Re: [PSES] Uncertainty in ESD testing
"If you can't stand the answer, don't ask the question." Oh how I wish you had been my lawyer during a couple of program manager inquisitions. I still would have been tarred and feathered, but the walk back to town would have been much shorter. Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, September 01, 2017 1:05 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Uncertainty in ESD testing I neglected to say in my previous post the obvious: we were discussing implementation of CS118, the new ESD requirement. Regarding charging in where angels fear to tread, MIL-STD-461 has since 1993 imposed measurement system integrity checks, wherein a known stimulus is applied to the transducer and the response at the EMI receiver is verified to be within +/- 3 dB, or the measurement system needs adjustment. For RE102, the radiated electric field requirement, that injection is always less the actual transducer, i.e., the antenna. The antenna is disconnected and the injection is made where the antenna would connect. This approach obeys a fundamental rule of life: "If you can't stand the answer, don't ask the question." Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Dranetz Hardware
A friend of mine is a consulting engineer in the hospital industry, and he has a sick Dranetz 626 Powerline Disturbance Analyzer. This unit is a boxy mainframe which accepts a dozen or so "input modules", a bit like the older Tektronix oscilloscopes had special purpose plug-in modules. Anyway, he would really like to get a schematic and documentation on the "AC to Neutral Line Monitor" plug-in (sorry, that's the best he can describe it, no model number) so that he can get his analyzer fully operational again. He has already tried Dranetz, but they said the early 80's hardware is no longer supported by them. Can anyone help out with some electronic documentation or maybe just some photocopies? Thanks in advance! Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Optical Viewing Product
I just bought a supply of paper/plastic solar eclipse “glasses” for the upcoming USA total solar eclipse (I’ll be in the desert in Idaho, hoping for clear skies). I thought you might be interested in the product markings on this product. [CE & ISO marks] Conforms to and meets the Transmission Requirements of ISO 12312-2, Filters for Direct Observation of the Sun. Meets the Transmission Requirements of EN 1836:2005 + A1:2007 € for an E15 Filter for the Direct Observation of the Sun. Meets the Transmission Requirements of AS/NZS 1338.1:2012, Filters for Eye Protectors. EC Type Examination by: SAI Global Assurance Services Ltd. (Notified Body No. NB2056. There’s more about addresses, and the vendor is identified as American Paper Optics of Bartlett, TN. www.3dglassesonline.com Also interesting that there is a warning to discard product after three years (although date of manufacture is not stated). We don’t often talk about optical standards, so I thought this marking, on a $2 consumer product (bought on Amazon), might be interesting for us. Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] USB dongle connector shield filtered grounding
Ken: I wonder which currency symbols could best be substituted for each of the many ground symbols? Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Wednesday, June 28, 2017 1:03 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] USB dongle connector shield filtered grounding Bill, thanks for the complement. One of my mentors, Dr. Tom Van Doren, of the University Missouri - Rolla, would say “the more different “ground” symbols he saw in a schematic, the more business he knew he would get”. Ken ___ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 56 Aspen Dr. Woodland Park, CO 80863 Phone: (719) 310-5418 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] RF CS High Current Test Level [General Use]
Can the low frequency portion (100 Hz to 50 kHz) be met with an iron-core transformer coupling method, such as for the CS101 Method? Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Thursday, May 04, 2017 7:35 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF CS High Current Test Level [General Use] And the FCC injection clamp I recommended suffices for that on the low side, which is why I made that comment. The OP seems to need/want a clamp that will inject 1.7 amps at 10 kHz, and into the calibration fixture 100 ohm load, that is just flat wrong. Ken Javor Phone: (256) 650-5261 _ From: "Price, Andrew (Leonardo, UK)" <andrew.p.pr...@leonardocompany.com> Date: Thu, 4 May 2017 14:22:45 + To: Ken Javor <ken.ja...@emccompliance.com>, "EMC-PSTC@LISTSERV.IEEE.ORG" <EMC-PSTC@LISTSERV.IEEE.ORG> Conversation: [PSES] RF CS High Current Test Level [General Use] Subject: RE: [PSES] RF CS High Current Test Level [General Use] Ken There is no requirement that is flat but there are a few that require such a high level 1A, 1.7A, 3.98A over the range 2MHz to 30MHz. Regards Andy Andrew Price Land & Naval Defence Electronics Division Prinicpal Environmental Engineer (EMC) Leonardo MW Ltd Sigma House, Christopher Martin Rd, Basildon SS14 3EL, UK Tel EMC LAB : +44 (0)1268 883308 Mobile: +44 (0)7507 854888 andrew.p.pr...@leonardocompany.com leonardocomapany.com HELICOPTERS / AERONAUTICS / ELECTRONICS, DEFENCE AND SECURITY SYSTEMS / SPACE P Please consider the environment before printing this email. From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: 04 May 2017 15:14 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF CS High Current Test Level *** WARNING *** This message has originated outside your organisation, either from an external partner or the Global Internet. Keep this in mind if you answer this message. Don't know what requirement/limit you are testing to, but a limit that is flat below 500 kHz at a level near 2 amps is wrong. Ken Javor Phone: (256) 650-5261 _ From: Richard Jones <r.a.jo...@ieee.org> Reply-To: Richard Jones <r.a.jo...@ieee.org> Date: Thu, 4 May 2017 09:34:43 -0400 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] RF CS High Current Test Level Thanks Ken, That's the first piece of the puzzle covered, so still looking for 10KHz-400KHz and above 10MHz. Not sure if Fischer have a full solution for this but will ring them back to see :-) Does anyone know of other vendors who may be able to help? Rich On Wed, May 3, 2017 at 6:10 PM, Ken Javor <ken.ja...@emccompliance.com> wrote: FCC (Fischer Custom Communications) makes a very large clamp for the purpose you cite. http://www.fischercc.com/products/f-040128-1008-1a/ Although they don't show a data sheet, you can derive from the max input power and insertion loss that it's capable of injecting 2 amps. But only between roughly 400 kHz to 10 MHz. Ken Javor Phone: (256) 650-5261 <tel:(256)%20650-5261> _ From: Richard Jones <r.a.jo...@ieee.org> Reply-To: Richard Jones <r.a.jo...@ieee.org> Date: Wed, 3 May 2017 17:33:10 -0400 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] RF CS High Current Test Level Hi Folks Does anyone have experience generating 1.7A CW (10KHz - 400MHz) using Bulk Current Injection? Wondering how people have achieved it, is there a BCI on the market able to sustain this level "off the shelf" or a vendor who custom builds them? A possible alternative was to use multiple BCI's and a Power Splitter, but I can see this problematic at higher frequencies due to wavelength/phase etc I realise that you would need separate BCI's, splitting the test into frequency bands as no one BCI could do it all Thanks for any help provided Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantw
Re: [PSES] Passive Loop Emissions [General Use]
Ralph: I'm afraid that your explanation didn't get through to me. When I think of an electric field, I think of two voltage levels separated by a distance, so Volts per meter seems very descriptive. For instance, two plates, one meter apart, with one plate at 5 Volts and the other plate at 15 Volts, yields a field strength of 10 Volts per meter. Going logarithmic is simply a convenience for thinking about widely differing voltage levels, so again, very straight forward. Of course, you have to set a reference foe the log scale, so Volts or microvolts are equally valid. OTOH, mho/cm for a field is pretty obscure to me. Who uses that metric, and how? Ed Price WB6WSN Chula Vista, CA USA It's about as obscure as using "dBuV/m" for field strength Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ed Price [ <mailto:edpr...@cox.net> mailto:edpr...@cox.net] Sent: Monday, February 27, 2017 5:37 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Passive Loop Emissions [General Use] Andrew: I thought that S/m was a unit of electrical conductivity, defined as 0.01 mho/cm. This seems like a useless unit for magnetic field strength. I did find one site: <http://www.mdltechnologies.co.uk/wp-content/uploads/2012/05/6512-datasheet. pdf> http://www.mdltechnologies.co.uk/wp-content/uploads/2012/05/6512-datasheet.p df which provides a side-by-side chart for "dBS/m" and Electric Field Strength in "dB/m". At 10 kHz, the antenna factor in db/m is about 86 dB, while the antenna factor in dBS/m is about 35 dB. This sounds like the old relationship of magnetic field strength, in dBuA/m, to electric field strength, in dBuV/m, of 51.5 dB. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Price, Andrew (Leonardo, UK) [ <mailto:andrew.p.pr...@leonardocompany.com> mailto:andrew.p.pr...@leonardocompany.com] Sent: Monday, February 27, 2017 4:16 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> mailto:EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Passive Loop Emissions [General Use] Hi All I need some help in obtaining the correct result. The customer has requested an extended magnetic field emission test over the range 100kHz to 2MHz with a limit defined in dBpT. The antenna to be used is an EMCO 6512 which has it correction factors provided in dBS/m which the emission software used does not recognise. So is there a conversion factor that enables the right correction factor to be entered or is the conversion factor only used once a result is obtained?? Regards Andy Andrew Price Land & Naval Defence Electronics Division Prinicpal Environmental Engineer (EMC) Leonardo MW Ltd Sigma House, Christopher Martin Rd, Basildon SS14 3EL, UK Tel EMC LAB : +44 (0)1268 883308 Mobile: +44 (0)7507 854888 <mailto:andrew.p.pr...@leonardocompany.com%3cmailto:andrew.p.price@leonardoc ompany.com> mailto:andrew.p.pr...@leonardocompany.com%3cmailto:andrew.p.price@leonardoco mpany.com> leonardocomapany.com HELICOPTERS / AERONAUTICS / ELECTRONICS, DEFENCE AND SECURITY SYSTEMS / SPACE * Please consider the environment before printing this email. Leonardo MW Ltd Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England & Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> mailto:emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> htt
Re: [PSES] Passive Loop Emissions [General Use]
Andrew: I thought that S/m was a unit of electrical conductivity, defined as 0.01 mho/cm. This seems like a useless unit for magnetic field strength. I did find one site: http://www.mdltechnologies.co.uk/wp-content/uploads/2012/05/6512-datasheet.p df which provides a side-by-side chart for "dBS/m" and Electric Field Strength in "dB/m". At 10 kHz, the antenna factor in db/m is about 86 dB, while the antenna factor in dBS/m is about 35 dB. This sounds like the old relationship of magnetic field strength, in dBuA/m, to electric field strength, in dBuV/m, of 51.5 dB. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Price, Andrew (Leonardo, UK) [mailto:andrew.p.pr...@leonardocompany.com] Sent: Monday, February 27, 2017 4:16 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Passive Loop Emissions [General Use] Hi All I need some help in obtaining the correct result. The customer has requested an extended magnetic field emission test over the range 100kHz to 2MHz with a limit defined in dBpT. The antenna to be used is an EMCO 6512 which has it correction factors provided in dBS/m which the emission software used does not recognise. So is there a conversion factor that enables the right correction factor to be entered or is the conversion factor only used once a result is obtained?? Regards Andy Andrew Price Land & Naval Defence Electronics Division Prinicpal Environmental Engineer (EMC) Leonardo MW Ltd Sigma House, Christopher Martin Rd, Basildon SS14 3EL, UK Tel EMC LAB : +44 (0)1268 883308 Mobile: +44 (0)7507 854888 <mailto:andrew.p.pr...@leonardocompany.com%3cmailto:andrew.p.price@leonardoc ompany.com> andrew.p.pr...@leonardocompany.com<mailto:andrew.p.pr...@leonardocompany.com > leonardocomapany.com HELICOPTERS / AERONAUTICS / ELECTRONICS, DEFENCE AND SECURITY SYSTEMS / SPACE * Please consider the environment before printing this email. Leonardo MW Ltd Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England & Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] lowest emissions 4k TV?
Brent & Jim: I am surprised that some compliance engineer from a TV or monitor company hasn’t stepped up, even if privately, to offer a purchase suggestion for a robustly quiet and immune test aid. Long ago, I had a contract testing big console Sony TV’s, and I sure knew that there were a few models that were more desirable (from a lab aid point of view) than other models. Somewhere around 2005, the CRT monitor which I used with the PC controlling my HP EMI data acquisition system suffered an expected fatal electrical injury. When I replaced it with a Viewsonic LCD monitor, I was pleasantly surprised to find that it did not increase the system noise level anywhere, and it also eliminated the 15.75 kHz harmonic train associated with the old monitor’s horizontal deflection frequency. BTW, I currently have two Toshiba 24SL410U combination TV/Monitors (one at my desk and another in my ham shack). Both have never shown any undesirable interactions with Wi-Fi, Bluetooth, cordless phones [yes, I still have one of those], iPhones or ham receivers (FWIW, anecdotal, no actual measurements ever made.) Ed Price WB6WSN Chula Vista, CA USA From: Brent DeWitt [mailto:bdew...@ix.netcom.com] Sent: Tuesday, January 10, 2017 1:11 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] lowest emissions 4k TV? I should have mentioned that, in this case, we (Bose Corp.) are the test lab and it's our equipment we're testing. We just came out with a couple of new audio-for-video devices that route HDMI through to pick out the 5.1 surround. Had a heck of a time finding good sources and sinks. Not sure there are very many test reports to be looked at since TVs are verification only device. I suppose that more might be found if they incorporate non-modular Wi-Fi or RF remotes.. Brent -Original Message- From: Jim Bacher Sent: Jan 10, 2017 8:15 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] lowest emissions 4k TV? It is ok to post recommendations on devices that are good for testing to this list. As the list is archived one can always search the archives for such things. I have used several approaches to finding good support devices. I have like others looked at FCC test reports. For the most part it was after getting recommendations to make sure it was a good choice. I look to make sure it was tested properly and had 6 dB of margin. That allows for production variations. I have on rare occasions looked for good support devices on the FCC website. I have also contacted compliance engineers at the company of interest to see what they recommend. In one case they told me not to use theirs. Not everyone supplies all support devices needed for testing. So the test labs do have support devices. Therefore you can ask your test lab as well, as they might have favorite support devices. Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Practical ethics? -- text version
Many years ago, my wife presented me with a 24” wide needlepoint plaque that still hangs above my computer today. The plaque depicts a scroll, emblazoned with the word “ENGINEER.” Below the scroll is the legend “FAULTLESS > ACCURATE” I am fairly certain that my wife had no knowledge of relational operators, yet this makes a comment on the engineering mindset that is sometimes painfully accurate. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Monday, December 26, 2016 5:58 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Practical ethics? -- text version Being ethical doesn't mean that you must have god-like insight and foreknowledge. You are still a human, with human limitations. With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] British question, about a BS1363 plug-in power supply
I assume that the TARDIS wiring plan is more complicated than external appearances suggest. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org] Sent: Thursday, December 15, 2016 12:20 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] British question, about a BS1363 plug-in power supply Some wiring can get more complicated. J. R. R. Tolkien's house had 9 rings for the humans, 7 for the dwarves and 3 for the elves. I presume that there was a fairly large circuit breaker for the one ring-main to rule them all. I heard that the electrician kept muttering something about his "precious" being missing when that main breaker tripped. Ted Eckert Microsoft The opinions expressed are my own and do not necessarily reflect those of my employer or Sauron. -Original Message- From: John Allen [ <mailto:john_e_al...@blueyonder.co.uk> mailto:john_e_al...@blueyonder.co.uk] Sent: Thursday, December 15, 2016 11:06 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] British question, about a BS1363 plug-in power supply Ralph Following on from John W's post, some larger properties will have more than 2 ring-mains, plus a number of dedicated branches/spurs/radials for larger loads such as cookers, fixed water heaters and so on. In additional branches/spurs/radials can be used for areas where the ring approach might not be appropriate for physical reasons - such as adjacent sheds, garages and so on - and these would be over-current limited to the cable ratings because the diversity principle obviously cannot be applied. Thus, normal domestic ring main circuits would be required in 2.5mm "twin and earth" cable (another fairly unique UK concept where the grounding conductor is reduced in size) and be protected by a 32A breaker, whereas branch/spur/radial using the same cable must be protected by 16A breakers. BTW: UK fuses and breakers generally follow the IEC standards approach and are rated for continuous running at the stated rating, in contrast to the N.American convention where the fuses/breakers are rated their blow-ratings - thus a 16A UK/IEC breaker can be run at 16A continuous whereas a N.American 15A breaker cannot be run continuously run at 15A. John E Allen W.London, UK. -Original Message- From: Ralph McDiarmid [ <mailto:ralph.mcdiar...@schneider-electric.com> mailto:ralph.mcdiar...@schneider-electric.com] Sent: 15 December 2016 18:30 To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] British question, about a BS1363 plug-in power supply An interesting design philosophy which has benefits, but it seems to rely on pluggable appliances having an appropriate size fuse in their cordage. You could for example wire an entire house with 3 or 4 of these circuits, rather than a panel full of circuit breakers so common in N.Am Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric *Please consider the environment before printing this e-mail -Original Message- From: John Woodgate [ <mailto:jmw1...@btinternet.com> mailto:jmw1...@btinternet.com] Sent: Monday, December 12, 2016 1:50 PM To: Ralph McDiarmid < <mailto:ralph.mcdiar...@schneider-electric.com> ralph.mcdiar...@schneider-electric.com>; <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] British question, about a BS1363 plug-in power supply A 32 A breaker connects to a loop of 2.5 mm^2 3-core cable (line, neutral and protective). A large number (there is a limit but it's complicated) of 13 A wall outlets can be connected to this ring, relying on diversity to keep the total current below 32 A. With best wishes DESIGN IT IN! OOO - Own Opinions Only <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -Original Message- From: Ralph McDiarmid [ <mailto:ralph.mcdiar...@schneider-electric.com> mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, December 12, 2016 7:34 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] British question, about a BS1363 plug-in power supply What's a "ring circuit" ? Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Richard Nute [ <mailto:ri...@ieee.org> mailto:ri...@ieee.org] Sent: Saturday, December 03, 2016 12:01 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] British question, about a BS1363 plug-in power supply I understood the fuse in the U.K. plug was to protect the power cordage. In the U.K., outlets are supplied by a ring c
Re: [PSES] aluminum vs copper wiring
Another factor is that aluminum oxide is much harder and tougher to break through than copper oxide, further tending toward less reliable connectors. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Monday, December 12, 2016 3:35 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] aluminum vs copper wiring The coefficients of expansion are sufficiently different between aluminum and traditional wiring devices that connections would go loose over time, yielding a resistive connection and fire. The outer surface of aluminum is aluminum oxide, a non-conductor. To make a low-resistance electrical connection, the termination must break through the oxide. (Oxidation is almost instantaneous; welding of aluminum must be done in an inert atmosphere.) Best wishes for the holiday season, Rich > -Original Message- > From: Ralph McDiarmid > [mailto:Ralph.McDiarmid@SCHNEIDER- > ELECTRIC.COM] > Sent: Monday, December 12, 2016 11:50 AM > To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] aluminum vs copper wiring > > I've just come across this statement in a user manual for a > small inverter product: > > "Do not use aluminum. It has about 1/3 more resistance > than copper cable of the same size, and it is difficult to > make good, > low-resistance connections to aluminum wire" > > I think both statements are wrong. Science Data Book by > Oliver, lists resistivity of aluminum at about 1.5X > that of copper. And, I don't see why electrical connections > would be less reliable using aluminum, although, I do > remember household wiring in the USA was done with Al > some years ago with questionable success. > > Thoughts? > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > > > This message was scanned by Exchange Online Protection > Services. > > > - > -- -- > This message is from the IEEE Product Safety Engineering > Society emc-pstc discussion list. To post a message to the > list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> > > All emc-pstc postings are archived and searchable on the > web at: > <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online > Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ > can be used for graphics (in well-used formats), large files, > etc. > > Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ > Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including > how to unsubscribe) > List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> > Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> > David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David H
Re: [PSES] Anteroom needed for testing?
David: Ante-chambers can be used for shielding the EMI measurement equipment from external noise and they can be used to isolate the support and monitor equipment (needed exercise and evaluate the EUT) from the external environment. Isolation of the EMI equipment is nice, but I never found it necessary to shield the measurement equipment; careful attention to cable shielding, penetration quality, selection of computer controllers, equipment grounding & bonding and isolation of the power feeds always let me test to the most stringent emission requirements. (For TEMPEST testing, you should have a good ante-chamber, but we aren't talking TEMPEST requirements here. Further, I am excluding the possibility that you have arc welding, plasma cutters or other exotica nearby.) In military testing, I frequently had EUT's which required digital and analog input data and required the monitoring of outputs such as RF power level, spurious energy content, harmonics content, frequency accuracy, modulation accuracy and bit error rate, as well as monitoring of physical motion and even acoustic output characteristics. I would often require a suite of general purpose signal sources, as well as live GPS data, and multiple monitoring instruments, including audio microphones and video cameras. Typically, I might need two assistants just to operate & monitor the support equipment. One of the realities of life was that the EUT may be a deliverable, but the support equipment is all overhead. A program (customer) would often arrive at my lab with the most outrageous Rube Goldberg collection of support equipment (some dedicated controllers, a couple of laptops, some Radio Shack stuff and a whole lot of junk-box stuff), not realizing that all of this equipment could well contaminate the test environment or provide a path into the test chamber for environmental signals. For susceptibility evaluation, it was imperative that the support equipment not be susceptible to test chamber environments and that energy within the chamber not affect the support equipment or leak out into the environment. You don't want to fail the EUT when it's just the support equipment going crazy; you also don't want to crash your company's payroll computer either. Having an ante-chamber allows you to at least isolate the support equipment from the general lab environment (including the environment outside your lab). Further, you can control the interfaces between the support equipment and the EUT. General precautions are bandwidth limiting all interfaces and being very careful about cross-coupling and the creation of ground loops (fiberoptic cables are a great help with this, but they also have the complication of a fiber/copper conveter at each end, with its own emission/immunity profile). For a lab which tests only in-house products (which have predictable, simple interfaces that require relatively simple support equipment and for which you have built up an experience base), you probably don't need an ante-chamber. However, for a general purpose test house like TUV, you will be limiting your capabilities by not having at least one chamber with an associated ante-chamber. Should you accept a complicated test job, the complications of immediately having to deal with false fails, random data glitches or signals which each need to be proven false, can be an economic disaster and a reputation tarnisher. At my last lab, I added a very credible ante-chamber to my main chamber by utilizing a discarded 8' x 8' bronze screen enclosure with a manual door. This gave me about 90 dB of SE from the environment at minimal cost. I think that everyone should at least provide the space for an ante-chamber when they build a test chamber; even if you think you won't need an ante-chamber, you will have the floor space to add one in should you see the flexibility and financial benefits some day. Ed Price WB6WSN Chula Vista, CA USA From: Schaefer, David [mailto:dschae...@tuvam.com] Sent: Friday, December 09, 2016 7:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Anteroom needed for testing? All, We've been having a spirited internal discussion on the use of or need to have anterooms when testing for RF susceptibility and emissions. It seems like chamber manufacturers are moving away from them, and some engineers I've talked to also aren't seeing the need for their use. We recently built a lab in Florida, and they don't have any anterooms. At my lab, we have customers that have to run cable through the bulkhead to monitor their equipment. We've seen radio, television, and other signals brought straight into the chamber, which was eliminated by closing the anteroom door. So I'm asking - what are your experiences? How do you eliminate potential noise sources? Is everyone just moving to using fiber, including manufacturers coming to commercial labs for testing? Are there any standards, technical reports, or white
Re: [PSES] EN 302 195 Distance Conversion Factor
As Gert points out, extrapolation is fraught with hazards of assumptions. If you absolutely must attempt to extrapolate data from extreme distances, like a 1-meter measurement to a 10-meter equivalent field, you should test the sanity of your extrapolation algorithm. For instance, it has been said that, at 10 meters, the emissions could not be measured (they were below the noise level of the detection system). The same was true at 3 meters distance. However, at 1 meter, signals were detected. My first thought is how certain are the 1 meter data? That is, were all measurements well above (maybe 6 dB) the noise level at 1 meter? However, let’s assume this is true. Since nothing was observed at 3 meters, it’s obvious that the field decay is greater than 6 dB over the 1 to 3 meter distance. It would greatly reinforce your claim of an accurate extrapolation algorithm if you had some empirical data to back up your scheme. For instance, could you show (and plot) the decay of the strongest emission, over the range of maybe ½ meter to 3 meters, at ½ meter increments? Once you have some field decay data, you could then try a regression to a formula for predicting decay. Since your emissions are likely not originating in a precisely defined antenna, the entire physical structure of your EUT is the antenna. Whatever extrapolation model you come up with will likely not be usable with other EUT’s, but it will probably be better than just assuming 1/(r^2) or 1/(r^3). I believe that the White EMC Handbook series had a formula for extrapolating from very near fields to far fields. The decay in the very near field was 1/(r^3), rolling off to 1/(r^2) as the wavelength decreased. The critical parameters were the distance to the EUT at the close distance, the wavelength of the emission and the distance to the EUT at the extrapolated distance. Perhaps this model is discussed in more modern EMC texts also. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Monday, December 05, 2016 10:46 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] EN 302 195 Distance Conversion Factor In the close field area E-field/H-field varies with 1/(r^2) OR 1/(^3) depending on the source and nature of it. In addition at close distances similar fields may have an opposite vector polarity (close to EUT) and may partially cancel each other. In general it is not a good idea measuring close field components to draw conclusions on radiated emission components at greater distances, as these components do not actually radiate. That is why you won’t find any conversion factors for frequencies below 30 MHz, at distances shorter than the close-far field transition zone. (lambda/2pi) Of course measurements in this area make sense about the EMI-level at the measurement point, and that is why some standards make measurements in the close field at a predefined distance. Changing that distance will make measurements incomparable. Regards, Ing. Gert Gremmen Approvals manager + ce marking of electrical/electronic equipment Independent Consultancy + Services Compliance Testing and Design for CE marking according to + EC-directives: - Electro Magnetic Compatibility 2014/30/EC - Electrical Safety 2014/35/EC - Radio & Telecommunication Terminal Equipment 99/5/EC Web: <http://www.cetest.nl> www.cetest.nl (English) <http://www.ce-test.nl> www.ce-test.nl (Dutch) <http://www.cetest.fr> www.cetest.fr (under construction) Phone : +31 10 415 24 26 --- This e-mail and any attachments thereto may contain information that is confidential and/or protected by intellectual property rights and are intended for the sole use of the recipient(s) named above. Any use of the information contained herein (including, but not limited to, total or partial reproduction, communication or distribution in any form) by persons other than the designated recipient(s) is prohibited. If you have received this e-mail in error, please notify the sender either by telephone or by e-mail and delete the material from any computer. Thank you for your co-operation. From: Grace Lin [ <mailto:graceli...@gmail.com> mailto:graceli...@gmail.com] Sent: Tuesday 6 December 2016 00:46 To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] EN 302 195 Distance Conversion Factor Dear Members, What is the appropriate distance conversion factor per EN 302 195, 9 kHz - 30 MHz? The limits were specified at 10m. Test data was too low to be detected at 10m and 3m. 1m distance was used to collect some data. EN 300 330 provides a chart for the distance conversion fact
Re: [PSES] Public view of this email server?
Doug: How would you feel if you knew that some law firm considering a lawsuit against your company, was searching for everything you might have said over the past 20 years, for evidence of utterances that might support their version of some item of contention? Or perhaps somebody was filing a complaint against your company, for reasons completely unrelated to you, but they searched for evidence of a “hostile corporate work environment” and found you making a joke about their purported sadness in 2007? I could see that one bad experience like that might make corporate legal departments put a chill on all participation in openly searchable forums like EMC-PSTC. I think what I’m saying is that I like the idea of my peers being able to search our archives, but beyond that, I see only liabilities. Ed Price WB6WSN Chula Vista, CA USA From: Doug Powell [mailto:doug...@gmail.com] Sent: Tuesday, November 22, 2016 2:15 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Public view of this email server? I have watched this conversation for a few days and now I am beginning to wonder what is all the angst about. I have been a member of the forum since about 1995 and the publically searchable archive is something I have used since the beginning. I find it very useful and have never assumed any level of privacy is expressed or implied. It is up to the individuals who make use of the forum to monitor their own privacy. Spam is generally not a problem but has occurred on occasion. In those cases a gentle reminder followed by a reprimand from the admins has been enough. In many ways this forum is patterned after the old BBSs or news groups (i.e. dejanews, yahoo groups) all of which were / are searchable. Best, Doug -- Douglas E Powell doug...@gmail.com http://www.linkedin.com/in/dougp01 From: d...@mac.com Sent: November 22, 2016 2:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Reply-to: d...@mac.com Subject: Re: [PSES] Public view of this email server? My policy has always been to never put anything in an email that I wouldn’t want to see on the front page of the newspaper. It’s served me pretty well so far… -- Doug Nix d...@mac.com When you put a thing in order, and give it a name, and you are all in accord, it becomes. >From the Navajo, Masked Gods, Waters, 1950 On 22-Nov-16, at 15:24, dward <dw...@pctestlab.com> wrote: Or say what you mean and don’t say it if you are afraid you will be embarrassed by it. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. From: Pete Perkins [ <mailto:0061f3f32d0c-dmarc-requ...@ieee.org> mailto:0061f3f32d0c-dmarc-requ...@ieee.org] Sent: Tuesday, November 22, 2016 10:47 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Public view of this email server? Dan et al, I hope that everyone realizes that in this day of wikileaks that no electronic correspondence is private anymore, whether or not you intend it to be. In this case we see clearly that the messages are archived and searchable – altho some may not have realized that prior to this time. Watch what you say – John Woodgate can supply the Latin phrase. :>) br, Pete Peter E Perkins, PE Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 <mailto:p.perk...@ieee.org> p.perk...@ieee.org From: Dan Roman [ <mailto:danp...@verizon.net> mailto:danp...@verizon.net] Sent: Monday, November 21, 2016 5:34 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Public view of this email server? See the footer attached to every message: All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html -- Dan Roman <mailto:dan.ro...@ieee.org> dan.ro...@ieee.org Original message From: "Kortas, Jamison" < <mailto:jamison.kor...@ecolab.com> jamison.kor...@ecolab.com> Date: 11/21/16 1:43 PM (GMT-06:00) To: <mailto:
Re: [PSES] Public view of this email server?
This does come as a surprise to me. I had thought that the email archive was searchable by being stored on the IEEE host, but I did not realize that anyone, anywhere in the World, could observe the conversations with a Google search external to the IEEE. I don’t think this is what we intended to do when this forum was set up as a private membership reflector email system. I would think that many compliance professionals, knowing that their affiliations and comments could be publicly observed, would be cowed into participating at only the most superficial level of technical and legal content. I generally believe in a free flow of information, but knowing that your every word can be monitored and used for whatever purpose by anyone capable of a keyword search simply has to have a chilling effect on candor within the regulatory compliance community. Or from a different perspective, what value does such openness return to our members and the regulatory compliance community? Since our forum still displays a notable lack of spam, I assume that membership in our forum (required for posting) is still personally controlled by our admins (and a word of thanks to them for their service). Ed Price WB6WSN Chula Vista, CA USA From: Dan Roman [mailto:danp...@verizon.net] Sent: Monday, November 21, 2016 5:34 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Public view of this email server? See the footer attached to every message: All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html -- Dan Roman dan.ro...@ieee.org Original message From: "Kortas, Jamison" <jamison.kor...@ecolab.com> Date: 11/21/16 1:43 PM (GMT-06:00) To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Public view of this email server? Hi All, Maybe I am the only one who didn’t know this, but I found a thread in which I had I participated in a Google search. I did not know these emails were public in some way, at least enough to be found and indexed by Google. Just an FYI. The thread I found: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/msg72464.html -Jamison - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Internal point of coupling
IPC sounds like the bureaucratic definition of a wall outlet. Ed Price Chula Vista, CA USA -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Friday, November 18, 2016 12:47 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Internal point of coupling Yet one more acronym to try to remember. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric *Please consider the environment before printing this e-mail -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Friday, November 18, 2016 6:49 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Internal point of coupling I'm not a power engineer, and I've had to learn their little ways, so perhaps I can explain. You have a dozen machines in one building. They are all connected to a busbar in that building, and from the busbar a cable runs to the power transformer feeding the whole site. That busbar is an IPC. It's significance for EMC is that if one machine causes voltage disturbances at the busbar due to large currents during start-up, or, as in the case I am writing about, injects currents at harmonics of the power frequency, other machines connected to that same busbar may be adversely affected. Machines in other buildings are somewhat protected from those effects by the impedances of the cables from the buildings to the transformer. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -Original Message- From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Friday, November 18, 2016 2:07 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Internal point of coupling This thread has tickled my interest. I have never heard of the term IPC used in this way nor do I understand the definition. Can someone provide context and give an example of how it would be used? When the definition refers to "network", is this the AC Mains network? And why is the Point of Coupling a significant point of concern? Thanks. The Other Brian -Original Message- From: Andre Gomes Videira [mailto:ago...@weg.net] Sent: Friday, November 18, 2016 7:06 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] RES: [PSES] Internal point of coupling Hello John, The definition is in IEC 61000-2-4. IEC 61800-3, which is the EMC standard for PDS, states that the IPC is defined in IEC 61000-2-4 as "In-Plant Point of Coupling". >From IEC 61000-2-4, item 3.1.7: IPC - "point on a network inside a system or an installation, electrically nearest to a particular load, at which other loads are, or could be, connected. Note: The IPC is usually the point for which electromagnetic compatibility is to be considered" André Gomes Videira Laboratório de Ensaios e Certificações Telefone: + 55 47 3276-7613 | Skype: agvideira WEG Drives & Controls - Automação Ltda. www.weg.net -Mensagem original- De: John Woodgate [mailto:jmw1...@btinternet.com] Enviada em: sexta-feira, 18 de novembro de 2016 08:59 Para: EMC-PSTC@LISTSERV.IEEE.ORG Assunto: [PSES] Internal point of coupling I am looking for a definition (preferably formal) of 'Internal point of coupling' for a proposed IEC Technical Report. It is not in Electropedia and is mentioned (as IPC) In IEC 61000-2-6 without definition. I am told that it might be defined in one of the IEC 61800 series standards, but there are several of them. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> Clique http://disclaimer.weg.net/; target=_blank>aqui caso voc no seja o destinatrio deste email, ou desejar conhecer nossa poltica de privacidade. Click http://disclaimer.weg.net/; target=_blank>here if you are not the intended recipient, or in case you want to know our privacy policy. -
[PSES] Server Magnetic Field Susceptibility
You might find these several videos interesting in that they show a very large Neodymium magnet (undefined field strength) being exposed to three commercial servers: https://www.youtube.com/watch?v=4l-6qWaZpVQ Shipping and handling issues related to the magnet: https://www.youtube.com/watch?v=1zO9nWgI_LY And a partial autopsy of a failed server cooling fan: https://www.youtube.com/watch?v=_n3pNjJovYA Are your customers playing with your products like this? If you have the time and interest, these videos have links to other imprecise, poorly planned H-field exposure tests. Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] CE for military aeronautical product
When the military (the UK MoD) makes a purchase, it is done as a contract between MoD and the vendor. The MoD can impose any requirement it wishes as a condition to the contract. Most of the time, a Test Procedure is a contractually required line item, and must be submitted to the MoD for approval. This TP will often have variations to normal military standards (they call it tailoring) to accommodate validating an unusual military system to the spirit of the military standard. Further, the MoD can impose requirements beyond the USA MIL-STD-461 or UK DEF-STAN 59-411. In this case, if the MoD wants you to state the uncertainty of measurements used to obtain your test data, they can stipulate that your TP define exactly how you calculate those uncertainties for every test. The customer is king, whatever he wants (subject to his agreement to pay for), he can demand, and if you want the sale, you will comply (although at the TP stage, considerable technical negotiation is possible, hopefully you and your customer are not adversarial). The MoD is not constrained to accepting only what is printed in 59-411 or 461. When I was selling combat instrumentation ranges to the MoD, they also required UK radiation safety standards and also had provisions for compliance with some UK civilian safety standards. How we intended to show compliance of a military system to those civilian standards was defined in the TP. Military products may use a lot of hazardous substances, so the contract should define if certain parts (or all) of the delivered system are subject to RoHS. Since military equipment will eventually be salvaged or sold commercially, subsystems may either be required to never contain hazardous substances, or, provision should be made for demilitarizing the subsystem at the end of its life. So, as John says, ask the customer (read the Request for Quotation in all its intricate glory) and clarify as required. Indeed, I often received RFQ's that were confusing, duplicative or even had impossible/conflicting stipulations built-in; the first order of business was to create agreement of the customer's desires with reality and what we thought was possible. Ed Price WB6WSN Chula Vista, CA USA From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Wednesday, October 19, 2016 2:36 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] CE for military aeronautical product I think you have to ask the military customer what they want. I'm not sure that RoHS even applies to military equipment. With best wishes DESIGN IT IN! OOO - Own Opinions Only <http://www.jmwa.demon.co.uk/> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. From: Amund Westin [mailto:am...@westin-emission.no] Sent: Wednesday, October 19, 2016 7:58 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] CE for military aeronautical product As far as I understand, military products shall be CE marked when used in Europe. What will be the case when CE marking a military computer used in a military aircraft? LVD does not apply (low DC voltage) and RTTE/RED does not apply because there is no wifi or any radio module inside. For EMC, the new 2014/30/EU says in Article 2: . shall not apply to aeronautical products, parts and appliances to the Regulation (EC) No 216/2008 .. I have to admit, I have not been through the entire Regulation (EC) No 216/2008, but it seems to me that EMC directive does not apply. So what is left? ROHS? . Should the DoC for a military computer installed in a military aircraft only makes reference to the ROHS directive? I would say yes. #Amund - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.
Re: [PSES] When is EMI testing performed?
Gert: Many years ago, I operated a little company building RF shielded rooms and buildings. I found that beer at the end of the job was a much better idea than beer during the job. Alas, I never developed a taste for beer, so I had to content myself with root beer. Ed Price WB6WSN Chula Vista, CA USA Thanks Ed, In spite of -not much to be learned- , I do appreciate sharing. May I conclude that many EMC/EMP tests have a happy end... and beer ? Regards, Ing. Gert Gremmen Approvals manager + ce marking of electrical/electronic equipment Independent Consultancy + Services Compliance Testing and Design for CE marking according to EC-directives: - Electro Magnetic Compatibility 2004/108/EC - Electrical Safety 2006/95/EC - Medical Devices 93/42/EC - Radio & Telecommunication Terminal Equipment 99/5/EC + Improvement of Product Quality and Reliability testing Education Web: <http://www.cetest.nl> www.cetest.nl (English) Phone : +31 10 415 24 26 --- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] When is EMI testing performed?
Gert: I really don't have all that much experience with EMP testing; in the past 12 years, I have put three systems through HIRF & EMP using the USN facilities at Patuxent River, MD. .System 1 was an airborne instrumentation pod that had a secure data link back to ground assets. We were lucky that the entire airborne portion of the system was contained in a streamline pod, so except for the intentional signal ports and the aircraft power interface, the pod provided complete metallic SE. We concentrated on bandwidth limiting the ports, filtering and limiting the power interface, and on mechanical build of the pod skin. We passed without incident, so it could be argued that we also didn't learn anything. .System 2 was the ground segment of an unmanned airborne vehicle secure data link. This was essentially a pedestal mounted parabolic tracking antenna with some signal processing boxes. During RS103, we found unexpected failures, tracing them to a rotary slip-ring joint on the azimuth axis of the pedestal. The cause was found to be the improper specification of a commercial slip-ring joint instead of the military version (which was carefully shielded). If this hadn't been caught in RS103, I'm sure this would have failed EMP. When a proper, much more expensive (J) joint was installed, RS103 was easily passed and so was EMP. But again, no specific EMP test lessons either. .System 3 was a secure data link that I won't describe. Despite what we thought was careful design, this system had RE102 & RS103 issues. We had to use several different modular power supplies, change the layout of an RF deck, double-shield two cables and use about 20 EESeal connector filters on internal cables. Finally (after a lot of schedule slippage), it went through RE102 & RS103 just fine, but failed one of the HIRF tests. We didn't have a clue, but in talking over the experience, someone said that lots of systems had been failing that one test recently. Hmmm, my suspicious nature came out. After talking in excruciating detail with the test lab personnel, we get them to run some tests with our system partially and then fully shut off, and miraculously, their lab monitor equipment reports another failure. The lab guys worked all night on the equipment test stand, their cabling and the shielded monitor hut, and with no further explanation, we passed the next day. (And that was the very last environmental qualification test to be finished, so many unhappy people began breathing again.) Lesson learned was "oh thank goodness, it wasn't my junk after all; beer for everyone." Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: ce-test, qualified testing bv - Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Tuesday, October 04, 2016 9:50 PM To: Ed Price; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] When is EMI testing performed? Hi Ed, Can you share with us some typical EMP caused defects, and their cause/fix ? Most of us do not share your experience in this Regards, Ing. Gert Gremmen Approvals manager + ce marking of electrical/electronic equipment Independent Consultancy + Services Compliance Testing and Design for CE marking according to EC-directives: - Electro Magnetic Compatibility 2004/108/EC - Electrical Safety 2006/95/EC - Medical Devices 93/42/EC - Radio & Telecommunication Terminal Equipment 99/5/EC + Improvement of Product Quality and Reliability testing Education Web: <http://www.cetest.nl> www.cetest.nl (English) Phone : +31 10 415 24 26 --- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] When is EMI testing performed?
Ken: Mostly, it was the fear that the system would fail EMP. We had no way of getting an exposure test any closer than 0.5% of the required level, so the risk of failure during the actual test was difficult to quantify, and this really frightens the program people. I would cajole best practices as strongly as I could, try to over-engineer what I could get away with, and closely look at cable routings and build quality, but I still was never sure what my odds were. A secondary reason was that scheduling an EMP test date was often longer than the rest of the environmental test program; the last couple of times, I had the hardware sitting around for over a month until the EMP testing was due. (And fortunately, both passed on the first try!) Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Tuesday, October 04, 2016 2:04 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] When is EMI testing performed? Ed, Was EMP last because it might break things, or because the EMP people wanted to see how the equipment fared after an accelerated life regime? Ken Javor Phone: (256) 650-5261 _ From: Ed Price <edpr...@cox.net> Reply-To: Ed Price <edpr...@cox.net> Date: Tue, 4 Oct 2016 12:13:31 -0700 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] When is EMI testing performed? In a military or space vehicle market, it was common for several systems to be moving in parallel through the environmental qualification test program. One system would often see rugged physical testing, where failures could be very serious setbacks (salt fog immersion, blowing rain, sand & dust, helium leak testing, solar exposure, transportation shock, drop testing, explosive shock exposure), while another system would be going through temperature cycling, vibration, and other more benign tests. This latter system would usually end up with me doing the acoustic noise and electrical tests (frequency & voltage extremes, power efficiency, start-up transients, and applicable powerline/EMC suite). I don't know how the reliability engineers factored in how one test affected another, but I do know that, although the sequence of tests before my lab wasn't always in the same order, the power & EMC tests were usually the last of the environmental suite. Further, if it was applicable, the NEMP exposure was the very last test. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Tuesday, October 04, 2016 7:35 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] When is EMI testing performed? Have any of you ever seen EMI qualification intentionally scheduled at the end of environmental qualification for the purpose of assessing EMI performance after the suite of environmental tests has taken its toll? Thank you, Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org <mailto:emc-p...@ieee.org> <mailto:emc-p...@ieee.org> > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html <http://www.ieee-pses.org/emc-pstc.html> <http://www.ieee-pses.org/emc-pstc.html> Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ <http://product-compliance.oc.ieee.org/> <http://product-compliance.oc.ieee.org/> can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ <http://www.ieee-pses.org/> <http://www.ieee-pses.org/> Instructions: http://www.ieee-pses.org/list.html <http://www.ieee-pses.org/list.html> <http://www.ieee-pses.org/list.html> (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html <http://www.ieee-pses.org/listrules.html> <http://www.ieee-pses.org/listrules.html> For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org <mailto:j.bac...@ieee.org> <mailto:j.bac...@ieee.org> > David Heald: <dhe...@gmail.com <mailto:dhe...@gmail.com> <mailto:dhe...@gmail.com> > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Att
Re: [PSES] When is EMI testing performed?
In a military or space vehicle market, it was common for several systems to be moving in parallel through the environmental qualification test program. One system would often see rugged physical testing, where failures could be very serious setbacks (salt fog immersion, blowing rain, sand & dust, helium leak testing, solar exposure, transportation shock, drop testing, explosive shock exposure), while another system would be going through temperature cycling, vibration, and other more benign tests. This latter system would usually end up with me doing the acoustic noise and electrical tests (frequency & voltage extremes, power efficiency, start-up transients, and applicable powerline/EMC suite). I don't know how the reliability engineers factored in how one test affected another, but I do know that, although the sequence of tests before my lab wasn't always in the same order, the power & EMC tests were usually the last of the environmental suite. Further, if it was applicable, the NEMP exposure was the very last test. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Tuesday, October 04, 2016 7:35 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] When is EMI testing performed? Have any of you ever seen EMI qualification intentionally scheduled at the end of environmental qualification for the purpose of assessing EMI performance after the suite of environmental tests has taken its toll? Thank you, Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Susceptible Immunity / Immune Susceptibility
Having dabbled in both the military and commercial markets of EMC, I had always heard the military define susceptibility and commercial define immunity. I assumed that the difference was solely in the eye of the beholder, either a pessimist or an optimist. Nobody wants to be susceptible while everyone wants to be immune. Is there an issue of difference between the two terms, that they may have some intrinsic bias toward, or from, a point of view? Ed Price WB6WSN Chula Vista, CA USA IEC/CISPR classes all of those as immunity. With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -Original Message- From: dward [ <mailto:dw...@pctestlab.com> mailto:dw...@pctestlab.com] Sent: Friday, September 30, 2016 7:26 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] [RFI] Part 15 isn't enough.. Do not confuse susceptibility of interference with immunity such as ESD, Fast Transient, etc. The susceptibility spoken of is that of Spectrum Protection, and the protection of licensed users, not ESD, RF immunity, etc. Again, this is not immunity in the sense of radiated immunity, ESD, Fast Transient etc., but susceptibility only in regards to protection of the spectrum. Dennis Ward - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] [RFI] Part 15 isn't enough..
Dennis: Not true. Congress passes a Communications Act, a law, and it directs the FCC to implement that law. These Acts may stand for years or may be superseded with a new Act whenever Congress wants to write a new one. The FCC proposes Rules which it thinks will implement the spirit and letter of that Communications Act, and then the maneuvering begins. The FCC currently has no basis of law to “protect the consumer,” but if Congress wishes to do so, the FCC will be mandated, funded and expanded to enforce Congressional wishes. Ed Price WB6WSN Chula Vista, CA USA From: dward [mailto:dw...@pctestlab.com] Sent: Friday, September 30, 2016 10:04 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] [RFI] Part 15 isn't enough.. Nor will there ever be anything in the FCC rules about immunity simply because that, as Gherry state, has nothing to do with the protection of the Spectrum. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, September 30, 2016 9:03 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] [RFI] Part 15 isn't enough.. The intent of the quoted statute is simply to protect licensed users of the spectrum from unlicensed unintentional “poachers.” The licensed user paid for their use of the spectrum, and any unlicensed “poacher” must cease and desist his use when it interferes with the operation of a licensed user. It also says that one unlicensed user has no protection from another unlicensed user, and certainly not from a licensed user. Basically just laying out a “pecking order” in terms of rights to use the spectrum. Nothing here about immunity at all. Ken Javor Phone: (256) 650-5261 _ From: "Paasche, Dieter" <dieter.paas...@christiedigital.com> Reply-To: "Paasche, Dieter" <dieter.paas...@christiedigital.com> Date: Fri, 30 Sep 2016 12:59:04 + To: <EMC-PSTC@LISTSERV.IEEE.ORG> Conversation: [PSES] [RFI] Part 15 isn't enough.. Subject: Re: [PSES] [RFI] Part 15 isn't enough.. In general I believe that changing part 15 will be very difficult since it is a legal (political) document and would need congress approval for changes. Different that than in the EU where you have directives and harmonized standards somehow separately. Also the US is part of international committees and heavily participates on emissions and immunity standards. However implementation and enforcing is always difficult. And finally, isn’t FCC indirectly stating that immunity has to be met as well? FCC Part 15.5 (b) §15.5 General conditions of operation. (a) Persons operating intentional or unintentional radiators shall not be deemed to have any vested or recognizable right to continued use of any given frequency by virtue of prior registration or certification of equipment, or, for power line carrier systems, on the basis of prior notification of use pursuant to §90.35(g) of this chapter. (b) Operation of an intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference is caused and that interference must be accepted that may be caused by the operation of an authorized radio station, by another intentional or unintentional radiator, by industrial, scientific and medical (ISM) equipment, or by an incidental radiator. (c) The operator of a radio frequency device shall be required to cease operating the device upon notification by a Commission representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected. (d) Intentional radiators that produce Class B emissions (damped wave) are prohibited. Sincerely, Dieter Paasche This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large fi
Re: [PSES] ELECTRIC SHOCK AS IT PERTAINS TO THE ELECTRIC FENCE
It would appear that the real problem was lack of a GFCI breaker on the motor circuit, which would have tripped open when the current in/out ratio became unbalanced. Ed Price WB6WSN Chula Vista, CA USA From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com] Sent: Wednesday, September 21, 2016 4:42 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] ELECTRIC SHOCK AS IT PERTAINS TO THE ELECTRIC FENCE Well here’s one recent electric shock effect, the cause of which may be more interesting to understand than the resulting death. http://www.newsobserver.com/news/state/north-carolina/article101748857.html Tragic death of a lifeguard getting electrocuted while reaching into the pool and then probably being incapacitated and drowning. The published laymen’s cause was due to a faulty pump motor that did not trip the circuit breaker due to a corroded wire. Bad bonding connection I assume. Imagine if the failure had occurred with a pool full of swimmers. -Dave From: Pete Perkins [mailto:0061f3f32d0c-dmarc-requ...@ieee.org] Sent: Wednesday, September 21, 2016 5:29 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] ELECTRIC SHOCK AS IT PERTAINS TO THE ELECTRIC FENCE Doug, et al, This fine early work is the foundation for later workers such as Dalziel, etc. which provides the basis for understanding electric shock effects. Note that you can only download the whole, very clear copy if your organization has a membership in the digital library in which this copy is stored. Papers such as these are the central core of work that is the basis for the development of IEC 60479 series which deals with the effects of electric shock on the human body. That group, IEC TC64/WG4, has a library of these important basic papers (including the Whittaker paper referenced here) which is used for reference in their work. Thanx to Rich for summarizing this paper. :>) br, Pete Peter E Perkins, PE Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 <mailto:p.perk...@ieee.org> p.perk...@ieee.org From: Douglas Nix [mailto:d...@mac.com] Sent: Wednesday, September 21, 2016 12:32 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] ELECTRIC SHOCK AS IT PERTAINS TO THE ELECTRIC FENCE You can view a good quality copy of this seminal work online at https://babel.hathitrust.org/cgi/pt?id=uc1.$b661851;view=1up;seq=3 -- Doug Nix d...@mac.com (519) 729-5704 Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind. - Dr. Seuss On 21-Sep-16, at 13:52, Richard Nute <ri...@ieee.org> wrote: Underwriters Laboratories did basic research in the field of safety and published the results of that research in a series of “Bulletins of Research.” At least 58 bulletins were published relating to fire, explosion, and electric shock. One of those Bulletins, “Electric Shock as it Pertains to the Electric Fence,” is a classic document in the field of product safety. The research was performed from 1936 to 1939 by Baron Whitaker, an Assistant Electrical Engineer at UL. Whitaker ultimately ascended to the presidency of UL. Whitaker’s research still stands today. While similar research has been done in support of modern IEC publications, such research is usually published only in IEC committee papers and is usually highly focused towards the specific standard or report the IEC is attempting to write. This UL Bulletin of Research on the electric fence contains much information that applies to much more than just the electric fence. This is why it is a classic work. Whitaker wanted to determine the maximum value of current, for both ac and dc, the frequency, and the duration that “can be considered as not being hazardous to human life.” Whitaker undertook to determine values for: 1. Body electrical resistance 2. Safe open-circuit voltage. 3. Effects of dc, interrupted dc, ac, and frequency of ac. 4. The maximum current and duration which will not cause bodily injury. 5. The minimum off time. <https://www.prisonlegalnews.org/media/publications/taser_ul_electric_shock_analysis_1955.pdf> https://www.prisonlegalnews.org/media/publications/taser_ul_electric_shock_analysis_1955.pdf Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used forma
Re: [PSES] Fire ants & Circuit Breakers
As I understand things (in my American-centric world), a GFCI duplex outlet protector contains a toroidal core that senses the differential current between the Hot and Neutral conductors. The magnetic field is pretty well-contained within that toroid core. Electric fields are dependent of the applied voltage and the physical structure of the conductors, but I don’t think there any reason to expect E-fields from a GFCI to be any different than E-fields from a standard duplex outlet. Also, the GFCI duplex outlet protector only senses differential current (which it assumes is attributable to a ground fault); it does not sense load current nor does it trip to open the circuit due to current overload. A typical 1-pole circuit breaker (in a home distribution box) senses load current and opens the circuit due to an overload. It uses two methods of current sensing, thermal and electromagnetic. The thermal sensing consists of a bimetallic leaf that carries the load current, experiences Ohmic heating and applies a force to a trip mechanism. The electromagnetic sensing consists of a solenoid coil that carries the load current, a straight cylindrical core and a lever that also exerts force on the trip mechanism. The thermal system is aimed at sensing long-term loads while the electromagnetic system is aimed at sensing short-term loads. As the thermal system deliberately generates heat, the breaker case will run a bit warm. As the electromagnet system uses an open, cylindrical core, it will create a non-uniform magnetic field. I have never tried to measure this field, but insects sensitive to magnetic fields would certainly sense the magnetic field around a loaded circuit breaker. (Perhaps some circuit breakers have shielded cases, but I have never seen anything other than plastic.) That’s a basic circuit breaker; they get more complicated with incorporating GFCI and AFCI sensing directly in the breaker. However, I’m speculating that the major H-field contribution comes from that solenoid current sensing subsystem. And that’s about all I know about shrimp, I mean GFCI’s. Ed Price WB6WSN Chula Vista, CA USA From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Thursday, September 15, 2016 5:42 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fire ants Does a GFCI also produce stronger electric fields than occur in other boxes? But magnetic field sensitivity is quite possibly the explanation. With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk/> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. From: IEEE [mailto:d...@ieee.org] Sent: Thursday, September 15, 2016 1:25 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fire ants I wonder if there are any entomologists that are studying this effect? Has anyone looked up any of the ant specialists to see if they’ve been exploring this phenomena? WRT to Don’s experience, I wonder if it’s the magnetic field that is attracting them more than the electric field? The GFCI has some toroidal current transformers that might be part of the attraction… I was also wondering if the abdominal signalling/pheromone release behaviour following the electric shock was a call to battle with a perceived enemy, against which they could not win. I guess if you pile on enough dead ants you can eventually trip the breaker feeding the circuit, and the ants “win”, at least in the moment. Anyway, sounds like we need some bug guys involved in this discussion… Doug Nix d...@ieee.org +1 (519) 729-5704 On Sep 15, 2016, at 06:14, Gies, Don (Nokia - US) <don.g...@nokia-bell-labs.com> wrote: Yes. I had a GFCI 20A circuit breaker in my panel feeding my pool pump motor. I went to open my pool last spring and the breaker kept tripping. So, I concluded that the breaker went bad. I opened up the breaker panel to change the breaker and found that the GFCI breaker was infested with ants (regular ones, not fire ants), but interestingly, the GFCI breaker was the ONLY breaker in the entire panel that had ants. DON GIES NOKIA Bell Labs SENIOR PRODUCT COMPLIANCE ENGINEER GLOBAL PRODUCT COMPLIANCE LABORATORY 600-700 Mountain Avenue Room 5B-104 Murray Hill, NJ 07974-0636 USA Phone: +1 908 582 5978 Mobile: +1 732 207 7828 <mailto:don.g...@nokia-bell-labs.com> don.g...@nokia-bell-labs.com From: Doug Powell [mailto:doug...@gmail.com] Sent: Wednesday, September 14, 2016 6:04 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Fire ants All, I was wondering if anyone has any real experiences with fire ant infestation in electrical equipment that they would be willing to share. <http://articles.extension.org/pages/30057/ants-and-electrical-equipment> http://articles.extension.org/pages/30057/ants-and-electrical-equipment It seems to me that for high current co
Re: [PSES] Fire ants
Plutonium is probably not a good answer; even if we could induce each ant to carry off a microflake of Plutonium, who knows what the little buggers might assemble from those grains? I think recent research on fire ants shows that they develop mega-colonies because the ants recognize members of other colonies by a protein on the exoskeleton. Thus recognized, the returning ants are not killed as would normally happen to a member of another colony. Instead of an insecticide, it’s possible to disrupt that exoskeleton protein and the returning worker ants will be killed by their own kind. Colonies will be put into civil war, with colony defenders killing off the colony food gatherers. We may have to consider negotiation. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Wednesday, September 14, 2016 8:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fire ants Two to three years to evolve a resistant strain. Then what? Plutonium? With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -Original Message- From: Nyffenegger, Dave [ <mailto:dave.nyffeneg...@bhemail.com> mailto:dave.nyffeneg...@bhemail.com] Sent: Thursday, September 15, 2016 1:44 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fire ants Just keep some Terro inside the electrical boxes. Can't imagine the wildlife peoples having an issue with that, not they would ever know. - - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Fire ants
My area is plagued by the Argentine ant, Linepithema humile. Wikipedia has a number of articles on various ants: https://en.wikipedia.org/wiki/Argentine_ant I was surprised to find that these ants have formed one huge mega-colony that extends from San Diego to San Francisco. We recently had good success putting out bait stations that function by allowing the ants to carry tiny bits of bait back to the colony, when the ants are killed by ingestion of the bait. This year, this technique has been very successful. I suppose, since the ants carry the poison away from your property to somewhere else, you could be accused of technically poisoning other species, and contaminating land, by inadvertant exposure. Sounds like a great area for legal adventures. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com] Sent: Wednesday, September 14, 2016 5:44 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fire ants Just keep some Terro inside the electrical boxes. Can't imagine the wildlife peoples having an issue with that, not they would ever know. -Original Message- From: Brian O'Connell [ <mailto:oconne...@tamuracorp.com> mailto:oconne...@tamuracorp.com] Sent: Wednesday, September 14, 2016 6:47 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fire ants Nothing ever reported from employer's customers. Twice during last 13 years have had to replace contactor for well pump due to red ants (dunno if they were solenopsis xyloni, but the horned lizards love them for lunch) that have become somewhat common in Riverside county. The first contactor flamed out, and breaker eventually opened. Afterwards, put large fuses in series and put contactor in separate box, so the second flame-out did much less damage, and only replaced contactor and wires to the TB. Am reticent to use insecticide, as the Kalifornia wildlife peoples consider mine and adjacent properties habitat for endangered/threatened species, and there can be big fines. Not certain for the reason the ants want to go into electrical boxes and conduits. As the owner of a 'wildlife refuge', wonder why ESPN has not offered to do a special series on "Tracking the Range and Behavior of the Untamed Engineer" ? Brian From: Doug Powell [ <mailto:doug...@gmail.com> mailto:doug...@gmail.com] Sent: Wednesday, September 14, 2016 3:04 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Fire ants All, I was wondering if anyone has any real experiences with fire ant infestation in electrical equipment that they would be willing to share. <http://articles.extension.org/pages/30057/ants-and-electrical-equipment> http://articles.extension.org/pages/30057/ants-and-electrical-equipment It seems to me that for high current contractors and electrical disconnects (not using self-wiping contacts) with contaminants between connection points can result in resistive connections, I^2R heating, potential arcing and if enough voltage is present, series arc faults which over time can erode connections and result in a fire. Does anyone have experience with this as a real problem? Thanks Doug -- Douglas E Powell <mailto:doug...@gmail.com> doug...@gmail.com <http://www.linkedin.com/in/dougp01> http://www.linkedin.com/in/dougp01 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Eng
Re: [PSES] Fuses can affect performance other than safety!
Rich: I once hired a new engineer whose family owned a really huge hog farm in Iowa. He told me that memories of having to drive the Bobcat hauling hog manure kept him motivated in his studies. I think we need a Bobcat to handle Synergistic’s claims. Ed Price WB6WSN Chula Vista, CA USA From: Richard Nute [mailto:ri...@ieee.org] Sent: Monday, August 22, 2016 4:12 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fuses can affect performance other than safety! If you put a carefully-chosen fuse in series with a loudspeaker, you can measure intermodulation distortion in the voice-coil current due to the element changing its resistance with temperature. What would be the parameters of a fuse that would minimize the element changing its resistance with temperature and still meet fuse operating requirements? How much resistance change would result in measurable intermodulation distortion? Can you explain any of the claims? “Synergistic Research Quantum Fuses employ a custom alloy treated with 2,000,000 volts of electricity! SR Quantum Fuses significantly outperform all other high-end fuses on the market and are guaranteed to deliver a noticeable increase in sound staging, resolution and air thanks to a lower noise floor and blacker backgrounds.” “Synergistic Research RED Fuses feature proprietary alloy burn wires and end caps encased in anti-resonant ceramic bodies. RED fuses are then treated with 2,000,000 volts of electricity in a process we call Quantum Tunneling that alters the conductor at a molecular level for optimum performance. Unique to SR RED Fuses is a new treatment process applied exclusively to SR RED Fuses that realigns the crystal structure of both the burn wire and the end caps for a refinement in high frequency characteristics and improved timbre linearity. All told SR RED fuses significantly outperform every other high-end fuse on the market and are the only fuses guaranteed to deliver a significant increase in system performance or your money back. When compared to our award winning SR20 Quantum Fuses, SR RED Fuses sound more refined with smoother highs and more linear frequency extension from the deepest bass to the highest highs; no small feat given the remarkable performance of our original SR20 Quantum Fuses.” Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Need a LARGE Chamber
Ken: “I can’t imaging ANYONE allowing you to test an incinerator in their chamber! Ha!” Well hah I say right back to you. J In the 80’s, I built a 50’ long shielded enclosure (Fred Nichols of LMI did the installation) for EMC testing of turbine APU’s (aircraft Auxiliary Power Units). Beyond the normal EMC considerations, the APU’s presented several really interesting issues: ·The shielded chamber had a 10’ x 10’ removable end panel to allow for rolling the APU’s in on a test cart. ·I had to install chain mail shields inside the enclosure to contain hurtling turbine blades, should the turbine wheel fail. ·I had to build a shielded hot exhaust port in the side of the shielded enclosure. ·I had to install a huge fume extractor system in the enclosure wall (in case of a false start, the chamber could fill with a fog of explosive/flammable fuel). ·I had to install multiple shielded air vents in the shielded enclosure walls because when that turbine gets running, its one heck of a vacuum cleaner. (The shielded enclosure wall loading with even a 0.1 psi pressure differential would have been 7 tons.) ·I had to install a resistive load bank within the enclosure to load the APU’s (lots of heat, but then air motion was great). ·I had to create a fuel farm of 55-gallon jet fuel drums outside the enclosure (with anti-spill containment berms). ·I had to provide for about 20 high-pressure air cylinders (each about the size of a welder’s oxygen tank) inside the shielded enclosure to provide for air-starting of some APU’s. ·And this being Southern California, I had to get a permit from the very cranky Air Pollution Control District to allow me to burn all that jet fuel in a non-aircraft application. And I had to create and get approved a hazardous materials abatement plan (in case I spilled some jet fuel). Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Friday, August 12, 2016 8:43 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Need a LARGE Chamber Hmmm Doug, well that’s an interesting one. You might consider doing what John McCloskey (Chief EMC Engineer for NASA’s James Web Space Telescope) did and perform the immunity tests on just the electronics control package, rather than the whole enchilada (in John’s case, the entire satellite). You should be able to simulate the actual incinerator in some way, such that the essential testing is done to just that part of the system that is most meaningful. You might want to listen to John’s keynote presentation at http://www.emclive2016.com as it may be directly applicable to your situation. You may gain some interesting insight. I can’t imaging ANYONE allowing you to test an incinerator in their chamber! Ha! Cheers, Ken - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Need a LARGE Chamber
Doug: Can you perhaps think outside the incinerator for a moment? Consider that a shipping container can be a decent shielded enclosure (with proper attention to penetrations, seams and door gasketing). It's my guess that you could achieve 80 dB SE across a wide spectrum, so a figure of 40 dB SE would be very conservative. Now think of what the shielded boxes are protecting from an external environment (a generator, electrical distribution and control system, air conditioning and environmental controls and a shredder with associated control electronics). If you want to operate this equipment in the presence of 50 V/M external fields, and you are living inside a 40 dB SE box, then your electronics would only have to withstand (50 V/M) / 100) or 0.5 V/M. Wow, do you think you can find industrial electronics that can withstand a half-volt per meter RF all on their own? So, the scenario that I'm suggesting is that you prove the capability of the unshielded electronics to work to say, 1 V/M, and you prove the SE of the containers / interconnections to provide 40 dB of SE. And don't forget that SE is symmetrical, so you can demonstrate SE "inside out" (that is, generating the strong RF field inside the enclosure, precluding RF environmental hassles). Do that, and you can claim immunity to 100 V/M external fields. Prove the immunity a bit higher (maybe 3 V/M) and the SE another 20 dB stronger, and your client can claim immunity to 3,000 V/M and sell this incinerator as capable of working on a carrier flight deck. BTW, it sounds like this incinerator will need external kerosene and obviously vents to the atmosphere. The fuel line can be treated like any other physical penetration that is a waveguide below cutoff. The exhaust vent will be perhaps 18" diameter and will transport very hot gasses. I would worry about particulate size, but you could install a high-temperature honeycomb structure inside the stack to maintain SE of the container. You may need to make the filter a quick-service module of the stack to allow for periodic cleaning or replacement. (I used this technique successfully for an NSA shielded "aircraft hangar" in Colorado which had its own dedicated power plant within the shielded volume.) It's mostly a mechanical engineering, not EMC, challenge. Ed Price WB6WSN Chula Vista, CA USA From: Douglas Nix [mailto:d...@mac.com] Sent: Friday, August 12, 2016 8:31 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Need a LARGE Chamber I am working with a client that is building a portable incinerator system that is built into three full-size sea containers and burns diesel fuel as the primary fuel. It has a stack that is about 60 ft when fully assembled. We need to do a fully assembled test, and I need access to either a BIG chamber with a hole in the roof, or a remote OATS where I can to a 50 V/m radiated immunity test. Oh, and it needs to be in Canada. Any help would be appreciated! -- Doug Nix d...@mac.com If you pick up a starving dog and make him prosperous, he will not bite you; that is the principal difference between a dog and a man. - Mark Twain - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> F
Re: [PSES] iNARTE EMC accreditation - thoughts?
Jim: You live in a World where accreditations are linked to market success. People are reassured by a flock of compliance markings on the back of a widget, even if those people are so dense as to strongly believe CE is the marking for "China Export." Since the ultimate "product" you want to dominate its market is yourself, it makes sense to know your customer and motivate him with a warm and fuzzy feeling about you. When you are flashing your BSEE in the competition of other BSEE's, I wouldn't hesitate to also make it known that I'm an iNARTE Certified such and such, and that I'm synergistic, lemon-flavored and play well with others. You are constantly being evaluated by others (many who will never meet with or talk to you), and many of them will be mightily impressed that you have iNARTE credentials and can emboss your iNARTE seal on your weekly reports. So, why not make them happy, secure and proud to employ you? And seriously, although I have not looked at iNARTE exam questions in a long time, I know that the exams are tough and I would respect anyone who earned those credentials. That's not such a bad deal; respect from expert customers and awe from consumer-grade customers. Regarding EMC accreditation itself, it began similar to a Roman Collegium and moved under the national aegis of NARTE. Perhaps this is the way of the World, but NARTE began expanding their accreditation business until EMC was just a small part of their empire. Then NARTE vastly improved their image (if not the ability of members to pronounce the acronym) by rebranding as an international organization, iNARTE. Soon iNARTE sold itself to an Australian accreditation group with the guaranteed unpronounceable acronym of RABQSA, and I began to feel like EMC accreditation was just a small brick in somebody else's ziggurat. The latest development is that RABQSA has rebranded to Exemplar to avoid strange-name jokes. Still, regardless of the etymology, Exemplar does provide the only (that I know of) EMC-specific accreditation credentials World-wide. (Of course, there is another career path that makes use of EMC skills. This is the NSA directed TEMPEST world [let's call it the Puzzle Palace's regulatory compliance World], and there is an Accredited TEMPEST Engineer program [but I don't think they want you using a neat paper embosser to advertise that]). Hmm, if you are the type of guy who worries about counting the levels of nested parentheses, you might be a TEMPEST kind of guy! So sure, sit for the exams and once you pass, you can claim the annual dues as an employee business expense (same for your IEEE & EMC Society dues [I'm assuming USA tax structures, YMMV.]). And if you become a consultant, the credentials may help bolster your image as a professional in tax matters such as an Office-in-Home situation. Ed Price Ex-iNARTE Certified EMC This J Ex-iNARTE Certified EMC That J Chula Vista, CA USA From: Pawson, James Sent: Wednesday, August 10, 2016 10:01 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] iNARTE EMC accreditation - thoughts? Hello fellow engineers, With an eye on the future, I am considering taking an iNARTE EMC qualification. Specifically, I'm considering one (or possibly both) of these accreditations. . iNARTE EMC Design Engineer Certification . iNARTE Electromagnetic Compatibility (EMC/EMI) Certification I'm looking for your advice and experience of . Gaining these qualifications . Views of the engineering community on the worth of these qualifications . Suggestions as to which one of these would be most beneficial for a career in EMC either working as a company employee or as a contractor/consultant in EMC testing and design I appreciate these are open questions and I would appreciate any and all opinions. If you feel more comfortable replying off list then please do. Thanks and regards, James Pawson Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Standard Gain Horn Antenna Calibration
I'd like to expand a bit on horn antenna calibration durability. Most horns will show obvious damage if geometrically distorted by a collision or fall, so a visual inspection of the corners and flat planes should be normal practice every time you begin to use a horn. OTOH, there is one very vulnerable design point that will not show any evidence of damage; I'm talking about the feedpoint transducer or wave launcher. Some antennas have a waveguide flange, so you need to use a waveguide to coax adapter (because almost nobody uses flex waveguide back to their analyzer equipment). Other horns will have this built into the antenna. Both have the same weak point, although it is cheaper to replace an external adapter than a whole antenna. Most all of the waveguide to coax adaption schemes use a small probe which extends into the waveguide and is contiguous with the center pin of the coaxial fitting. The position and length of the probe within the waveguide is critical, any variation will have large effects on efficiency (ACF) and SWR. Now, here's the danger; suppose you have a nice heavy coax cable, maybe like RG-213, but the tech who assembled the N connector was a bit sloppy and allowed the center coax pin to extend too far from the end of the connector. When you firmly mate that N male coax connector to the N female coax connector on the coax to waveguide adapter, you may apply axial pressure to the N female center pin. The result is that the N female coax pin pushes the little probe out of critical position, and you never notice it. Ken is right when he tells us that you can detect this by electrically looking down the coax. But how many of us regularly check our coax cable connectors for dimensions, even with a go/no go set of mechanical gauges, let alone do a VSWR/return loss test every time we hook up a horn antenna? I'll bet that very few engineers do a check like this (except for the ones who have already been bitten by this problem, and even then, you get complacent after a few years J). I'm not sure how probable this scenario is, but it can happen, it happened to me and I've seen this at other labs too, so it's something we should be aware of as long as horns are designed the way they are. BTW, getting back to horn calibration, I always left the external waveguide to coax adapter permanently affixed to any calibrated horn antenna. That way, the adapter was periodically calibrated as part of the antenna, and I eliminated the potential issues of cleanliness/conductivity of flange faces, bolt torques, and having to keep track of separately calibrated adapters. Adapters are cheap compared to the cost of an antenna, so dedicating an external adapter to a waveguide antenna makes sense to me. Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, August 08, 2016 6:55 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Standard Gain Horn Antenna Calibration Up-front disclaimer: I have zero knowledge of the cited IEEE standard. That being said, the title excludes antennas, and it would seem that a discussion of antenna critical dimensions would be outside its scope in any case. The critical dimensions of a horn are those affecting its gain and match to a transmission line. The gain is set by the open aperture dimensions, and the match is set by the flare angle and also (if applicable) the functioning of a waveguide-to-coax adapter. The latter can be checked measuring vswr into the horn from the transmission line, and that is easy to check measuring return loss mid-band using a directional coupler. Ken Javor Phone: (256) 650-5261 _ From: itl-emc user group <itl...@itl.co.il> Reply-To: itl-emc user group <itl...@itl.co.il> Date: Mon, 8 Aug 2016 04:30:04 + To: <EMC-PSTC@LISTSERV.IEEE.ORG> Conversation: Standard Gain Horn Antenna Calibration Subject: [PSES] Standard Gain Horn Antenna Calibration Hello All According to ANSI 63.4: 2014 Clause 4.7.3 "Standard gain horns need not be periodically recalibrated, unless damage or deterioration is suspected or known to have occurred. If a standard gain horn is not periodically recalibrated, its critical dimensions (see IEEE Std 1309-2005) shall be verified and documented on an annual basis." Can anyone point me in the direction of the clause in IEEE Std 1309-2005 which mentions critical dimensions? Thanks in advance. Regards, David Shidlowsky | Technical Reviewer Address 1 Bat-Sheva St. LOD 7120101 Israel Tel 972-8-9186113 Fax 972-8-9153101 Mail dav...@itl.co.il/e...@itl.co.il Web www.itl.co.il <http://www.itl.co.il/> <http://www.itl.co.il/> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchab
Re: [PSES] Safety requirements in US
Dave: “Common denominator” thinking would have the people of Ohio paying for a product that would have California earthquake protection capability. Also, I doubt that California customers would be happy with products that would withstand Ohio earthquake standards. A Federal installation code is possible, but then it would take a bureaucracy the size of the IRS to administer it and would likely contain loopholes and customization down to the County and City level (Google tells me that there are 3,144 Counties and 19,354 “incorporated places” in the USA). It certainly would help employment for compliance engineers (both writing and interpreting it). Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com] Sent: Wednesday, July 27, 2016 5:59 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Safety requirements in US Well you know, what may be fine for Ohio may not be so much in earthquake prone California. Perhaps a minimum common denominator would be fine for all 50 states. -Original Message- From: Richard Nute [ <mailto:ri...@ieee.org> mailto:ri...@ieee.org] Sent: Wednesday, July 27, 2016 3:45 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Safety requirements in US > I cannot see a reason not to have a federal installation code for all > 50 states. The hodgepodge of local rules and regulations seems, on > the surface, unnecessarily > complicated. NIH. Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] outdoor EMC testing - questions
Bill: Yes, that can be acceptable, until you get an over-spec level and think the product fails. Then, you have to prove that the emission is truly associated with the EUT, and not an arc welder in the next building or the site security’s handy talkie. Sometimes you have to schedule the test to start at 10 PM on a Saturday to minimize the probability of local human activity. Using the EMI analyzer’s Video output with an audio amplifier & speaker helps you correlate the emissions; fully automated systems believe anything. Ed Price WB6WSN Chula Vista, CA USA From: Bill Owsley [mailto:00f5a03f18eb-dmarc-requ...@ieee.org] Sent: Wednesday, July 27, 2016 1:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] outdoor EMC testing - questions I had a larger EUT tested by an accredited lab in a large warehouse and the antenna was walked around to a bunch of points for the measurements. Before turning the EUT on, the ambients were recorded. After turn on, the deltas were attributed to the EUT and measured. _ From: Ghery S. Pettit <n6...@comcast.net> To: EMC-PSTC@LISTSERV.IEEE.ORG Sent: Tuesday, July 19, 2016 6:34 PM Subject: Re: [PSES] outdoor EMC testing - questions Ralph, We had an indoor setup similar to what you describe back in the 1980s when I worked for Tandem Computers. The downsides of such a set-up are numerous. We had a Memorex facility on the other side of the wall (I have no idea what they did there) and whenever we found a signal the first question was, "Is it real, or is it Memorex?" In the middle of a parking lot you are going to have the same question, over and over again. Is the signal coming from the EUT or someplace else? I hope the EUT starts and stops operating quickly as I can see a lot of "Turn it off! Is the signal still there? Turn it back on and keep tuning." In your future. And good luck in the FM broadcast band and the television broadcast bands. Back in the days of analog TV testing in the TV bands wasn't too bad. You had a 6 MHz wide channel with a carrier for audio and a carrier for video. The actual video information was pretty low and generally not a problem. Now with digital stations basically owning that 6 MHz channel from one end to the other testing at an OATS (or in a parking lot) where TV stations are plentiful is difficult. Depending on where you are you may lose the ability to test in a fair amount of spectrum. You will need a metal ground plane. Without it your chances of meeting NSA, especially in the vertical polarity, are slim. Best of luck. Let me know if you need more help. Ghery S. Pettit, NCE Pettit EMC Consulting LLC gh...@pettitemcconsulting.com -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Tuesday, July 19, 2016 10:01 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] outdoor EMC testing - questions Dear group, We are planning to do radiated emissions on a large EUT (a large power converter) and use a portion of our outdoor, asphalt parking lot as an open area test site. We plan to walk an antenna around the EUT, since the EUT and its cabling are too large to rotate on a platform. It will be installed in a way very similar to actual use in the field, so I think this is quite close to in-situ testing. 1. has anyone tried this? 2. apart from a site attenuation test, and perhaps a ground plane metal mesh, what else would be needed? We have facility filters for AC and for DC and voltage probe, current probe, one "BiConilog" antenna and a nice new SA. We are working with a US EMC company, and they are a Notified Body under the MRA. Thanks, Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric This message was scanned by Exchange Online Protection Services. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ <http://product-compliance.oc.ieee.org/> can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html <http://www.ieee-pses.org/list.html> (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> -
Re: [PSES] Friday Question
Doug: Strange, but just a few days ago I was following up the claims of a soft-science news story which claimed robots with “nine degrees of motion.” I couldn’t find anything to back up that claim. As far as I know, I agree with your limit of six. Hmm, maybe we could get philosophical and call time a dimension? (Would that be translation along the Serling axis?) Ed Price WB6WSN Chula Vista, CA USA From: Douglas Nix [mailto:d...@mac.com] Sent: Friday, July 22, 2016 2:50 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Friday Question Rich, Many industrial robots have six axes or more. They are often not described in the Cartesian manner you are using as the robot actually operates in a set of spherical coordinates. They still use x, y, z, by convention, but often you’ll also find x1, y1, z1, x2, y2, z2, etc. Doug Nix d...@mac.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Oscilloscope probe calibration
I have had many occasions where I got a scope back from metrology and they had checked the calibration of each input channel (usually using the 50 Ohm option), always separate of the probes. But even worse, they never seemed to check the front-panel calibration port (they treated that just like the many ports on the rear which were never actually calibrated or validated). Does your current calibration source test the parameters of the front panel calibration port? (I found it interesting that there was a trend to de-emphasize those calibration ports, moving them to the rear or sometimes not even having one.) Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Tuesday, July 12, 2016 9:39 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Oscilloscope probe calibration Doug, you’re such a tease! :-) ___ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 56 Aspen Dr. Woodland Park, CO 80863 Phone: (719) 310-5418 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Antenna gain measurement standard
Stephen: I will have to defer to someone who knows what 2D & 3D means, because I don’t. I have also not heard of “maximum” gain. Gain is usually defined along the radial of maximum emission, and despite most antennas being rather obvious which direction that is, the best way is actual measurement. Perhaps you know this already, but you can visualize radiation as the power radiating through an imaginary transparent sphere enclosing the antenna. An antenna will usually create a main lobe and many lesser sidelobes. Identifying the axis of the main lobe can be time intensive, especially if you have a complex antenna structure and no initial idea of how it will perform. The antenna gain will be a combination of antenna efficiency and directional gain (think of how a flashlight may have internal losses and a very narrow emission beamwidth). If you have a high directional gain, the beamwidth may be only a half-degree in both the azimuth and altitude axes, and finding the center of this invisible beam may take hours of scanning (as you have to scan every radial around the sphere). Accurate jigging is a must, followed by methodical investigation. Ed Price WB6WSN Chula Vista, CA USA From: Stephen Whalen [mailto:scwha...@bellsouth.net] Sent: Friday, July 01, 2016 12:17 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Antenna gain measurement standard Ed, Thanks for the response. I am looking to measure the gain of an antenna in order to calculate EIRP of a product. As far as the 2D vs. 3D, I don't have any values. I was hoping some one who has made measurements using both 2D and 3D would be able to comment how much better 3D is over 2D when considering peak gain. I appreciate your feedback, thanks. Stephen On Friday, July 1, 2016 3:00 PM, Ed Price <edpr...@cox.net> wrote: Stephen: There are a number of ways to measure gain, with the basic one being a comparison to a theoretical isotropic radiator (yielding a gain number in dBi). However, the antennas used for EMI and compliance testing are usually used in the near field, where the standard you are testing to defines the acceptable measurement distance and styles of antennas. Thus, there is often a preferred gain measurement technique defined by the standard you are working to. In regard to what you told us, what is 2D & 3D (dimension) gain? And what is peak gain? What standard is defining these terms? Ed Price WB6WSN Chula Vista, CA USA From: Stephen Whalen [mailto:scwha...@bellsouth.net] Sent: Friday, July 01, 2016 8:01 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Antenna gain measurement standard Greetings, Does anyone know which standard is used for measuring antenna gain? Are 3D antenna gain measurements typically different than 2D with regards to peak gain? If so, what's typical delta, 0.5dB or less? Regards, Stephen - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> On Friday, July 1, 2016 3:00 PM, Ed Price <edpr...@cox.net> wrote: Stephen: There are a number of ways to measure gain, with the basic one being a comparison to a theoretical isotropic radiator (yielding a gain number in d
Re: [PSES] Antenna gain measurement standard
Stephen: There are a number of ways to measure gain, with the basic one being a comparison to a theoretical isotropic radiator (yielding a gain number in dBi). However, the antennas used for EMI and compliance testing are usually used in the near field, where the standard you are testing to defines the acceptable measurement distance and styles of antennas. Thus, there is often a preferred gain measurement technique defined by the standard you are working to. In regard to what you told us, what is 2D & 3D (dimension) gain? And what is peak gain? What standard is defining these terms? Ed Price WB6WSN Chula Vista, CA USA From: Stephen Whalen [mailto:scwha...@bellsouth.net] Sent: Friday, July 01, 2016 8:01 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Antenna gain measurement standard Greetings, Does anyone know which standard is used for measuring antenna gain? Are 3D antenna gain measurements typically different than 2D with regards to peak gain? If so, what's typical delta, 0.5dB or less? Regards, Stephen - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] EMO vs EPO
My rather amateur opinion would be that an EMERGENCY STOP should be a rapid cessation to a safe state, but not necessarily an EMERGENCY POWER OFF. I could imagine a process being stopped but power being maintained to continue to monitor, cool, brake to stop or lock in place, something on the order of “I’m not going to do anything further, but I won’t let anything get worse or loose” condition. Ed Price WB6WSN Chula Vista, CA USA From: Doug Powell [mailto:doug...@gmail.com] Sent: Monday, June 27, 2016 11:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] EMO vs EPO All, Is there an official fine point distinction between Emergency Off (EMO), Emergency Power Off (EPO) and Emergency Stop or are they all equivalent and interchangeable terms? To my thinking, if there is a distinction, it would seem that Emergency Stop is related to mechanical hazards or moving parts, EPO is related to electrical hazards and EMO would be a general "catch all" acronym for any type of hazard whether mechanical, electrical, radiation, chemical, etc. Thanks! Doug -- Douglas E Powell doug...@gmail.com http://www.linkedin.com/in/dougp01 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Brexit and the European Compliance Complex
Now that the UK has voted to withdraw from the European Union, how will this affect the regulatory compliance landscape of the UK market? I have heard that trade into the EU represents about 6% of the UK's GDP (is that true). If that is so, then will the UK assert its own national compliance structure? Will the UK simply copy the existing EU compliance Directives, Norms and Standards (as they were already published in UK versions), or will the UK feel it necessary to have a complete new system? (I recall that the British MoD decided on this second option, essentially rewriting the US MIL-STD-461 as their own DEF-STAN 59-41 and then 59-411.) Is there a sense within the UK that having to follow the numerous, complex and opaque EU regulations (sorry to have to say that, but that seems to be >80% of all our conversations now) has become onerous and that a move to UK national regulations would be a chance to simplify and eliminate burdens? The current UK government was not enthusiastic about Brexit, so are there any predictions about how happily and efficiently it will move to complete the withdrawal (I understand that they have 2 years maximum). However, assuming that the current government does move ahead to comply with the will of their nation, what are the first significant changes that will affect both UK companies and foreign companies trading with the UK? Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light
The most recent batch of dimmable LED light bulbs that I have bought contained two switchers. (These were cheap lamps, about 700 Lumens for $3, to replace 60 Watt incandescent bulbs.) First was a constant current DC source, which was followed by a variable duty cycle series switch. In effect, the first supply converted the AC main to a constant current DC, and then the second switcher duty-cycle modulated (at about 50Hz, well above the eye flicker threshold) the constant current DC to the LED’s. (This allowed the LED lamps to be controlled by a simple ON/OFF switch or a typical residential duty-cycle modulated lamp dimmer. I don’t understand how the first power supply section can supply “constant current” when that current is being turned on and off by the second power supply section, but it seems to work fine. I don’t notice any bad effects, but if you rapidly waggle a finger back and forth, you can see some strobe effect of the light. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Brian O'Connell [mailto:oconne...@tamuracorp.com] Sent: Wednesday, June 22, 2016 3:22 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light LED assembly typically powered by CC source (essentially DC), so should be no mains-frequency flicker. There are some dimming schemes using constant freq/variable duty cycle, but the unless the off period is very long, freq should be too high for persistency of human vision. The cheaper drivers are typically single-stage flybacks with current FB only, so some have EMI problems. Brian -Original Message- From: Ralph McDiarmid [ <mailto:ralph.mcdiar...@schneider-electric.com> mailto:ralph.mcdiar...@schneider-electric.com] Sent: Wednesday, June 22, 2016 3:06 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light This seems a reasonable idea, in an attempt to approximate the intensity of existing lamps. ( turn 'em down a little! ) "The AMA recommends an intensity threshold for optimal LED lighting that minimizes blue-rich light" Depending on how these things are powered, I wonder if there might be a flicker problem at 50Hz? (similar to the CRT television frame rate flicker that was so noticeable to those of us used to the 60Hz rate) Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric -Original Message- From: Richard Nute [ <mailto:ri...@ieee.org> mailto:ri...@ieee.org] Sent: Wednesday, June 22, 2016 1:07 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light Thanks for the URL to the AMA website. Unfortunately, the AMA doesn't give any color temperature or intensity numbers for "harmful human and environmental effects of high intensity street lighting." So, how are we to know what is acceptable to the AMA? As safety engineers, we cannot design a suitable safeguard without these numbers. How do the AMA numbers (if any) compare with sunlight, the defacto standard? We have an old fluorescent backlight TV in our bedroom that we watch at night before we fall asleep. Is this any different light than a tablet or laptop allegedly causing insomnia? (Or is it the use of the tablet or laptop that causes the insomnia?) The TV display does not cause us insomnia, as far as I know, while the content often does. Here is a treatise on color temperature: <http://www.feit.com/color-temperature> http://www.feit.com/color-temperature Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim
Re: [PSES] FW: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light
John said: “There have been lots of press reports of medics advising not to use computers late at night because the blue light from the display can cause insomnia.” Wait, isn’t the monitor being able to keep you awake a positive effect? I mean, who among us has never had to delete 856 pages of the letter “c” that you find attached to the end of your latest status report? Ed Price WB6WSN Chula Vista, CA USA From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Wednesday, June 22, 2016 11:59 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] FW: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk/> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Wednesday, June 22, 2016 6:46 PM To: 'John Allen' <john_e_al...@blueyonder.co.uk> Subject: RE: [PSES] AMA Warns of Harm from LED Streetlights’ Blue Light There have been lots of press reports of medics advising not to use computers late at night because the blue light from the display can cause insomnia. With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk/> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Magnetic Field at 400 A/m
Ralph: The field within a solenoid coil is very uniform and predictable (it’s a expansion of the Biot-Savart equation). I built my own 3-axis sensor using a magnetoresistive chip sensor similar to this Honeywell design: http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/HMC5883L_3-Axis_Digital_Compass_IC.pdf You can find similar systems in the “maker” marketplace for under $20; IIRC, Adafruit provides these mounted to boards that mate with Arduinos and other microcomputers. https://learn.adafruit.com/adafruit-hmc5883l-breakout-triple-axis-magnetometer-compass-sensor/overview I’m a bit hazy on what I did a decade ago; I seem to have lost my entire notes for that part of the project. Anyway, the Honeywell sensor can measure up to 8 Oersteds, so you can prove the “coil factor” to yourself with 1% accuracy. (Remember that H-field scales directly with current.) You can also move this sensor around inside the coil volume to check the field uniformity. I just downloaded a free ap from the Apple Store, called “TeslaBot” and it’s now running on my iPhone. It turns the iPhone’s 3-axis magnetoresistive sensor into a magnetometer, displaying each axis simultaneosuly in µT plus solving and displaying sum of all three axes. (The point being, why not? I’m sure somebody will ask me about magnetic field sensing at the next party I attend!) My desktop ambient is 38µT, and if I move my old wireless phone near it, it shoots up to over 500µT. Of course, I have no idea of the absolute accuracy of that reading, but it would be interesting for someone with a coil to verify how accurate the iPhone sensor really is. At the very least, TeslaBot makes a good demonstrator for convincing upper management that EMI is real and they shouldn’t fire you. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Tuesday, June 21, 2016 9:28 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Magnetic Field at 400 A/m But how to calibrate such a thing, to know how much magnetizing force is really being applied to the DUT ? Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Manny Barron [ <mailto:mbar...@integrity.com> mailto:mbar...@integrity.com] Sent: Monday, June 20, 2016 7:54 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Magnetic Field at 400 A/m Back in 1996 when I managed a 3rd party EMC test lab and when the IEC 1000-4-8 test became mandatory, I built my first magnetic field test setup using a "hula hoop" from Toys-R-Us. I wound the appropriate amount of insulated wire loops inside it, and added an appropriate power supply/transformer and some low resistance high wattage resistors. It worked great for small products and the 3 or 10 A/m test levels. Today there are more aesthetically appealing test setups available from various suppliers. Manny Barron Sr. EMC Engineer From: Ed Price [ <mailto:edpr...@cox.net> mailto:edpr...@cox.net] Sent: Monday, June 20, 2016 7:01 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> mailto:EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Magnetic Field at 400 A/m Grace: I used to regularly test equipment to MIL-STD-1399, which had a DC magnetic field strength exposure requirement of 20 Oersteds, applied for 60 seconds. Since 1 Oersted is about 79.5 Amps/meter, that was equivalent to a 1600 Amp/meter field exposure. I did that with a Sorensen 50 ADC power supply, a 0.001 Ohm sense resistor, a DMM and a custom solenoid coil. The coil was wound with 163 turns of #12 solid wire, with a coil length of 711mm and a diameter of 590mm. This was adequate to expose a several unit high 19” rack-mount EUT. FYI, this antenna had an “antenna factor” of 2.217 Oersteds/Amp or 175.8 Amps/meter per DC applied Amp, with about 1.6 Ohms resistance. I built the solenoid coil using a “hazardous chemical disposal carboy” (think big strong plastic garbage can) with a cheap Harbor Freight appliance dolly bolted to one end. (Not only does this make the antenna easy to move, but it also greatly aids you winding that 1000 feet of #12 wire onto the carboy during several hours of Zen meditation.) Of course, if your EUT is smaller, then you don’t need such a large solenoid; I have a spreadsheet describing the design and performance characteristics of six solenoid coils I have built over the years. If anyone is interested, I have a description of the coil and the spreadsheet which I can send off-list. Ed Price WB6WSN Chula Vista, CA USA 1961 Amphicar 770 2001 Fleetwood Storm 31W 2008 Ford Explorer From: Grace Lin [ <mailto:graceli...@gmail.com> mailto:graceli...@gmail.com] Sent: Monday, June 20, 2016 4:18 PM To: <mailto:
Re: [PSES] Magnetic Field at 400 A/m
Grace: I used to regularly test equipment to MIL-STD-1399, which had a DC magnetic field strength exposure requirement of 20 Oersteds, applied for 60 seconds. Since 1 Oersted is about 79.5 Amps/meter, that was equivalent to a 1600 Amp/meter field exposure. I did that with a Sorensen 50 ADC power supply, a 0.001 Ohm sense resistor, a DMM and a custom solenoid coil. The coil was wound with 163 turns of #12 solid wire, with a coil length of 711mm and a diameter of 590mm. This was adequate to expose a several unit high 19” rack-mount EUT. FYI, this antenna had an “antenna factor” of 2.217 Oersteds/Amp or 175.8 Amps/meter per DC applied Amp, with about 1.6 Ohms resistance. I built the solenoid coil using a “hazardous chemical disposal carboy” (think big strong plastic garbage can) with a cheap Harbor Freight appliance dolly bolted to one end. (Not only does this make the antenna easy to move, but it also greatly aids you winding that 1000 feet of #12 wire onto the carboy during several hours of Zen meditation.) Of course, if your EUT is smaller, then you don’t need such a large solenoid; I have a spreadsheet describing the design and performance characteristics of six solenoid coils I have built over the years. If anyone is interested, I have a description of the coil and the spreadsheet which I can send off-list. Ed Price WB6WSN Chula Vista, CA USA 1961 Amphicar 770 2001 Fleetwood Storm 31W 2008 Ford Explorer From: Grace Lin [mailto:graceli...@gmail.com] Sent: Monday, June 20, 2016 4:18 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Magnetic Field at 400 A/m Dear Members, Does anyone know which standard requires to have magnetic field evaluated at 400 A/m? Is there any commercial available instrument (loop) for the purpose? Thank you very much for your time and I look forward to hearing from you. Best regards, Grace Lin - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm
Alfred’s comment reminds me that I just bought a fairly decent DMM, a Uni Trend UT-61E. This is an auto-ranging 5 digit, 60k count DMM with 0.1% accuracy on DCV, and it cost only about $65. One important feature is that this DMM includes an optically isolated USB interface, plus a free data acquisition suite for my laptop. With just a bit of effort, you could have your laptop monitor the data stream and provide alerts as desired (the software is already set up to create Excel files and create extensive data graphs). Ed Price WB6WSN Chula Vista, CA USA From: alfred1520list [mailto:alfred1520l...@gmail.com] Sent: Monday, May 30, 2016 12:23 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm If none of these meet your needs, you can always find any number of those with a programming API and write a program to do whatever you want. Many support USB interface. You can get a cheap windows tablet as the buzzer and attach to the meter through USB. Best regards, Alfred On May 30, 2016 10:57:38 AM PDT, Ken Javor <ken.ja...@emccompliance.com> wrote: Ken & Dieter, Thank you, but none of those really met my criteria. I’m looking for a piece of stand-alone test equipment, a multimeter, where I can set a limit and have the thing generate an audible tone (like during continuity testing) if the preset level is exceeded (or if a measured value is below the preset minimum). Datalogging is not of interest – what I need is a real-time alarm which I don’t have to visually monitor. It just seems like this should exist, and would be extremely valuable for a test facility to have available, custom configurable for a wide variety of thresholds. Ken Javor Phone: (256) 650-5261 _ From: Ken Wyatt <k...@emc-seminars.com> Reply-To: Ken Wyatt <k...@emc-seminars.com> Date: Mon, 30 May 2016 10:12:47 -0600 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm Maybe one of these could work. http://www.poweringthenetwork.com/site-power-monitor/ https://www.gavazzionline.com/pdf/DIB71CB.eng.pdf https://www.microdaq.com/data-loggers/voltage-current.php www.westell.com/document/ <http://www.westell.com/document/dc-power-monitoring/?dl=1> dc-power-monitoring/?dl=1 <http://www.westell.com/document/dc-power-monitoring/?dl=1> <http://www.westell.com/document/dc-power-monitoring/?dl=1> ___ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 56 Aspen Dr. Woodland Park, CO 80863 Phone: (719) 310-5418 Email Me! <mailto:k...@emc-seminars.com> <mailto:k...@emc-seminars.com> | Web Site <http://www.emc-seminars.com> <http://www.emc-seminars.com> | Blog <http://design-4-emc.com/> <http://design-4-emc.com/> The EMC Blog (EDN) <http://www.edn.com/blog/The-EMC-Blog> <http://www.edn.com/blog/The-EMC-Blog> Subscribe to Newsletter <http://www.emc-seminars.com/Newsletter/Newsletter.html> <http://www.emc-seminars.com/Newsletter/Newsletter.html> Connect with me on LinkedIn <http://www.linkedin.com/in/kennethwyatt> <http://www.linkedin.com/in/kennethwyatt> On May 30, 2016, at 9:56 AM, Ken Javor <ken.ja...@emccompliance.com> wrote: Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm For an EMI test, I need to monitor direct current and set a limit above which I get an audible alarm. I don’t want to constantly have to watch an ammeter/voltmeter while also operating the susceptibility equipment. I also don’t want to have to connect a DVM to a PC; I want the limit setting function to be self-contained. Seems as if there ought to be such a device, but I can’t find it. Doesn’t have to be an ammeter per se; if it can measure dc millivolts, I can use a current shunt. Thank you, Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> <http://www.ieee-pses.org/list.html&
Re: [PSES] Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm
Ken: I had a hand-held DMM, back around 1992, which did something close to that. IIRC, it was made by Beckman (which later sold that division to Fluke). It had the ability to create a tone whose frequency was proportional to whatever function and range you had selected. I found it very helpful in tracking down cable shield problems because you could set it for a resistance measurement and then walk around some big system shaking cables and structure pieces while listening to the tone. Setting it for DCV and connecting it to the video output on an EMC receiver would give me an audible indication of RF signal strength. Unfortunately, it was only proportional and you couldn't set an alarm or trip point. Seems like in these days of microprocessors everywhere, somebody ought to have a DMM option that has high/low limit set-points and even speaks to you. If any DMM you have has an output of some sort (like the ancient Simpsons VOM's had), you could build a simple oscillator and comparator into a small box and use that connected to that "monitor" output of your DMM. Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, May 30, 2016 10:58 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm Ken & Dieter, Thank you, but none of those really met my criteria. I'm looking for a piece of stand-alone test equipment, a multimeter, where I can set a limit and have the thing generate an audible tone (like during continuity testing) if the preset level is exceeded (or if a measured value is below the preset minimum). Datalogging is not of interest - what I need is a real-time alarm which I don't have to visually monitor. It just seems like this should exist, and would be extremely valuable for a test facility to have available, custom configurable for a wide variety of thresholds. Ken Javor Phone: (256) 650-5261 _ From: Ken Wyatt <k...@emc-seminars.com> Reply-To: Ken Wyatt <k...@emc-seminars.com> Date: Mon, 30 May 2016 10:12:47 -0600 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm Maybe one of these could work. http://www.poweringthenetwork.com/site-power-monitor/ https://www.gavazzionline.com/pdf/DIB71CB.eng.pdf https://www.microdaq.com/data-loggers/voltage-current.php www.westell.com/document/ <http://www.westell.com/document/dc-power-monitoring/?dl=1> dc-power-monitoring/?dl=1 <http://www.westell.com/document/dc-power-monitoring/?dl=1> <http://www.westell.com/document/dc-power-monitoring/?dl=1> ___ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 56 Aspen Dr. Woodland Park, CO 80863 Phone: (719) 310-5418 Email Me! <mailto:k...@emc-seminars.com> <mailto:k...@emc-seminars.com> | Web Site <http://www.emc-seminars.com> <http://www.emc-seminars.com> | Blog <http://design-4-emc.com/> <http://design-4-emc.com/> The EMC Blog (EDN) <http://www.edn.com/blog/The-EMC-Blog> <http://www.edn.com/blog/The-EMC-Blog> Subscribe to Newsletter <http://www.emc-seminars.com/Newsletter/Newsletter.html> <http://www.emc-seminars.com/Newsletter/Newsletter.html> Connect with me on LinkedIn <http://www.linkedin.com/in/kennethwyatt> <http://www.linkedin.com/in/kennethwyatt> On May 30, 2016, at 9:56 AM, Ken Javor <ken.ja...@emccompliance.com> wrote: Handheld or portable voltmeter/ammeter with built-in and adjustable limit function with audible alarm For an EMI test, I need to monitor direct current and set a limit above which I get an audible alarm. I don't want to constantly have to watch an ammeter/voltmeter while also operating the susceptibility equipment. I also don't want to have to connect a DVM to a PC; I want the limit setting function to be self-contained. Seems as if there ought to be such a device, but I can't find it. Doesn't have to be an ammeter per se; if it can measure dc millivolts, I can use a current shunt. Thank you, Ken Javor Phone: (256) 650-5261 - - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org
[PSES] measurement of transient radiation emission
Li: I am always suspicious of the suitability of highly automated instruments for capturing unusual signals in poorly conditions. While the analyzer system you describe may be very convenient, it appears to be inflexible; you are trading versatility and control of the acquisition parameters for push-button answers. Your complaint that you “couldn't get any transient signal on the spectrum analyzer” is a sign that you need to go below the automation and take control of the acquisition parameters (if your analyzer system will even allow that). I suggest that you discuss your acquisition problem with the manufacturer’s technical experts. (I’m pretty sure I could capture your transients on an old HP-141T Analyzer; this was hot technology in 1975 and a system can be bought on eBay for $500 or so. Not so great for today’s complex modulation schemes, but darned good for transients.) BTW, you seem to have answered one of my earlier questions to you; the “transient” that you wish to measure the spectrum of appears to be a single specific event. I suggest you investigate that transient event at some convenient frequency using a storage oscilloscope. Can you reliably predict the occurrence and duration (are multiple pulses present, is the first or last typically the highest) of the event from some indication? Perhaps you may be able to externally trigger the oscilloscope from some test specimen condition; that trigger may be helpful in acquiring a spectrum by triggering a spectrum analyzer. Ed Price WB6WSN Chula Vista, CA USA From: Li Di [mailto:li...@conorthtech.com] Sent: Thursday, May 12, 2016 9:15 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] measurement of transient radiation emission Hi Mr. Doug and the group, First, thanks a lot for all kind replies. I tried Aaronia HF60105 with BicoLOG 20100 antenna. Its minimal sweep time is 1ms. I couldn't get any transient signal on the spectrum analyzer. I tried to change the distance and position but failed to record. So I think HF60105 is too slow and it is not a real time tool. My next plan is to get a real spectrum analyzer. To keep down the cost, I need to choose the configuration of spectrum analyzer and antenna carefully. For this case, it is not necessary to get a very accurate result. For the use of o'scope, I did not try this with antenna. I just tried spectrum analyzer with a current probe to catch the conducted transient. In the facility, I think there are radiated transient and conducted transient. But I got nothing becaseu of the spectrum. Anyway, I will think about all advice later to try again. Best regards, _ Li Di Conorth Technologies Co., Ltd. --- Address: Room 212, Building C, No.15 Baiziwan Road, Chaoyang District, Beijing Tel (Fax): 0086-10-60530811 (Office) Mobile: 0086-13701332910 Email: li...@conorthtech.com Website: www.conorthtech.com <http://www.conorthtech.com/> -- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] measurement of transient radiation emission
Li: This is a classic problem with data acquisition, and has always been a time-consuming task. (I recall spending a couple of weeks obtaining CE & RE data on a thermal switch which was embedded in an aluminum heat sink in a military system. I had to modify the case to allow me to put a small hose against the thermal switch body, whereupon I alternately blew hot air and CO2 gas to farce switch cycles. Cycle time was about 10 minutes; just long enough to get very bored when the single CLICK would occur.) First, let's consider what is meant by "transient" emission. Is this noise from some single, large event or is it associated with all the unintentional emissions of a continuously operating system? Capturing noise from a single event requires that you wait until that event happens. Can you "force" the event without disturbing the system? And when the event happens, how representative is the amplitude of any one given event? In short, if you do capture the peak of the event, will the next event be noisier or quieter than the one you captured? Traditionally, this requires the capture of multiple events so as to predict the event performance. But, let's say you can force this event to happen more often than normal, and you then determine that each event is fairly predictable in amplitude. You can measure this noise event with a traditional EMI Receiver by just sitting at a frequency and using peak hold during the event. Once you have a reliable sample, you can manually tune to your next sample frequency. Ahh, now you ask how far you can skip to that second sample frequency, and the answer is that I don't know. Traditionally, a technician might tune to three frequencies per octave, but that may be too much spacing to catch some resonant condition. You may decide that you need 5 or 7 or more samples per octave (based on what your data looks like). You might have one octave where the noise is quite flat, but then in the next octave, resonant conditions predominate and your data looks like a roller coaster. Is your client concerned about ALL frequencies, or do they have some especially sensitive ranges? You can do the same with a spectrum analyzer (operating it in zero Hz bandwidth as a tuned receiver). If you allow the spectrum analyzer to sweep, then you can let it sweep a band (perhaps limited by your transducer), using peak hold, and randomly capturing the event wherever the analyzer bandpass happens to be during its sweep. You may need to allow the analyzer to run all night or even several days, just to build up a contiguous view of the transient spectrum. Perhaps you can automate an acquisition system by having a computer control frequency hopping, flagging each successful sample and never returning to a sampled frequency; this will hasten the buildup of samples for every frequency sample point by preventing duplication. BTW, if you rely on automation, you may acquire noise from other than your test specimen. You might be in the position of trying to validate an unusual data point which you suspect might be extraneous. Will you be measuring in a controlled environment (shielded chamber) or on a shop floor or a field site? You could have multiple analyzers observing at once, or even a colossal multi-channel analyzer, but you sound like you need a practical solution. The next step might be to measure the event in the time domain and predict the spectrum with a Fourier transform. And since I have nearly zero experience in this, I will have to let someone else fill in the story about the efficacy and limitations of this technique. Ed Price WB6WSN Chula Vista, CA USA From: Li Di [mailto:li...@conorthtech.com] Sent: Wednesday, May 11, 2016 10:52 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] measurement of transient radiation emission Hello All, I need to measure the transient radiation emission from a big industrial system. There is a discharg between its two electrodes with high voltage difference. My client wants to measure the transient interference at their facility. I plan to use spectrum analyzer and antenna (or near field probe). But the scan time of some spectrum analyzers is long. It is not easy to catch the inteference. Could anyone give me some advice? Thank you very much. Best regards, _ Li Di Conorth Technologies Co., Ltd. --- Address: Room 212, Building C, No.15 Baiziwan Road, Chaoyang District, Beijing Tel (Fax): 0086-10-60530811 (Office) Mobile: 0086-13701332910 Email: li...@conorthtech.com Website: www.conorthtech.com <http://www.conorthtech.com/> -- - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc
Re: [PSES] Anechoic Chamber Questions
The US DoD has fairly deep pockets, as evidenced by the Benefield Test Chamber at Edwards AFB. The Benefield chamber is about 250’ x 250’ x 70’ high. See: http://www.edwards.af.mil/shared/media/document/AFD-141126-061.pdf Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Allen [mailto:john_e_al...@blueyonder.co.uk] Sent: Saturday, April 30, 2016 8:45 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Anechoic Chamber Questions I think that before the practical limits come into play, financial limits will stop the designed chamber from further growing.. ;<)) Regards, Ing. Gert Gremmen Approvals manager + ce marking of electrical/electronic equipment Independent Consultancy + Services Compliance Testing and Design for CE marking according to EC-directives: - Electro Magnetic Compatibility 2004/108/EC - Electrical Safety 2006/95/EC - Medical Devices 93/42/EC - Radio & Telecommunication Terminal Equipment 99/5/EC + Improvement of Product Quality and Reliability testing Education Web: <http://www.cetest.nl> www.cetest.nl (English) Phone : +31 10 415 24 26 --- This e-mail and any attachments thereto may contain information that is confidential and/or protected by intellectual property rights and are intended for the sole use of the recipient(s) named above. Any use of the information contained herein (including, but not limited to, total or partial reproduction, communication or distribution in any form) by persons other than the designated recipient(s) is prohibited. If you have received this e-mail in error, please notify the sender either by telephone or by e-mail and delete the material from any computer. Thank you for your co-operation. From: Ghery S. Pettit [ <mailto:n6...@comcast.net> mailto:n6...@comcast.net] Sent: Friday 29 April 2016 19:42 To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Anechoic Chamber Questions In the words of an old colleague, “chambers and race cars are alike in that there is no substitute for cubic inches.” That said, absorber material works best when the angle of incidence is a close to straight in as possible. Thus, for a given separation distance between transmit and receive antennas (or source/EUT and receive antenna) the wider and taller the chamber, the better (within practical limits, of course). Other answers are noted below in red. Best of luck. Have fun! Ghery S. Pettit Pettit EMC Consulting <mailto:gh...@pettitemcconsulting.com> gh...@pettitemcconsulting.com (360) 790 9672 From: Pawson, James [ <mailto:james.paw...@echostar.com> mailto:james.paw...@echostar.com] Sent: Friday, April 29, 2016 12:14 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Anechoic Chamber Questions Hello all, I have some questions about anechoic chambers that I need some help with and I’m sure there is some expertise in this group that can help. 1. My understanding is that an anechoic chamber is meant to simulate a reflection-less, free space environment. Therefore if you move a source towards / away from the antenna, the signal level should follow the inverse square law – correct? That is the theory, anyway. ☺ 2. When comparing absorber types (hybrid + ferrite tile vs. foam absorber) the return loss characteristic gives the amount of absorption at a particular frequency – correct? Correct 3. If I wanted to compare effectiveness of foam absorber with hybrid + tile absorber is it just a case of adding the return loss of the hybrid to the return loss of the tile to achieve a final figure? My understanding is that the hybrid helps match the wave impedance from free space to that of the tile. Is the return loss of hybrid + tiles _together_ greater than the individual return losses of the separate components? Manufacturers that I’ve looked at list the data separately. The only number that really matters is the performance of the combination. I’m not sure that you can simply add them. 4. I have been told that the distance between absorber and a reflective metal backing is important for ensuring that the returning wave is in anti-phase (or at least as much as possible) with the incoming signal. However information on acceptable limits for this distance seems sporadic or in rarefied scientific papers behind paywalls. Does anyone have any info or experience on this point? While this might be true, keep in mind that the required distance would be a function of frequency. So, I wouldn’t lose too much sleep over this question. Many thanks for your time, I’m trying to get a handle on our chamber’s performance
Re: [PSES] Anechoic Chamber Questions
Jim: if you move a source towards / away from the antenna, the signal level should follow the inverse square law correct? At most frequencies, the wavelength is long compared to the dimensions of the shielded enclosure, so moving relative to the source is not done in a far-field condition and thus far-field relations dont hold up. the return loss characteristic gives the amount of absorption Yes, sort of. You may get some reflection from the front surface of the absorber. Thats a result of the absorber, but not exactly an absorption effect. The signal that does go through the absorber material then has to reflect off the shielded enclosure wall and then travel back through the absorber. So, the return signal has actually experienced two passes through the absorber and likely some scattering at the reflection. Still, it all adds up to a return loss. J with hybrid + tile absorber is it just a case of adding the return loss of the hybrid to the return loss of the tile Just moved past my level of experience, but I would expect that to not be true. I think you will see reflections due to mismatch at the absorber/tile interface, and this will affect the overall return loss. We need an expert to say how much. the distance between absorber and a reflective metal backing is important for ensuring that the returning wave is in anti-phase The reflected signal will be shifted 180° by the massive impedance discontinuity (the metal wall), and I never heard of spacing the absorber off the reflective surface for any advantage. There will be some small phase shifting in propagation through the absorber, as the velocity of propagation will be different from air. I have heard of critical thickness and internal spacings for absorbers intended for stealth aircraft, but these are very frequency selective. Paywalls are more like absorbers than reflectors, right? Ed Price WB6WSN Chula Vista, CA USA From: Pawson, James [mailto:james.paw...@echostar.com] Sent: Friday, April 29, 2016 12:14 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Anechoic Chamber Questions Hello all, I have some questions about anechoic chambers that I need some help with and Im sure there is some expertise in this group that can help. 1. My understanding is that an anechoic chamber is meant to simulate a reflection-less, free space environment. Therefore if you move a source towards / away from the antenna, the signal level should follow the inverse square law correct? 2. When comparing absorber types (hybrid + ferrite tile vs. foam absorber) the return loss characteristic gives the amount of absorption at a particular frequency correct? 3. If I wanted to compare effectiveness of foam absorber with hybrid + tile absorber is it just a case of adding the return loss of the hybrid to the return loss of the tile to achieve a final figure? My understanding is that the hybrid helps match the wave impedance from free space to that of the tile. Is the return loss of hybrid + tiles _together_ greater than the individual return losses of the separate components? Manufacturers that Ive looked at list the data separately. 4. I have been told that the distance between absorber and a reflective metal backing is important for ensuring that the returning wave is in anti-phase (or at least as much as possible) with the incoming signal. However information on acceptable limits for this distance seems sporadic or in rarefied scientific papers behind paywalls. Does anyone have any info or experience on this point? Many thanks for your time, Im trying to get a handle on our chambers performance and any answers will help. Regards, James - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are a
[PSES] Pre-Amp mounted to antenna
I forgot to add this on my last post. Nobody asked about a good pre-amp for use with that bias tee, but my favorite for this application is a Nuwaves HILNAV1 pre-amp; really low 0.8 dB NF, and they will sell you the bare-board pre-amp, so you don't have to mess with the big heat sink and case (you really don't need a heat sink, as it only draws about 70 mA @ 12 VDC). Also, if you ask them, they will give you a customized pre-amp that starts at 30 MHz instead of the advertised 50 MHz (top end is 1500 MHz, but I only used this to 1 GHz). Cost was only around $275 IIRC. http://nuwaves.com/products/low-noise-amplifiers/ You can combine this pre-amp with the MiniCircuits bias tee in a small aluminum project box (aluminum tape the seams) and hang it by its coax connector to the antenna RF port. Obviously, since the pre-amp and two bias tees are in the signal chain, you will need to do a thorough characterization of path loss, but since the finished test aid is so portable, my external metrology lab had no problem with calibrating the cable, injection tee, extraction tee and pre-amp as a single system, and at no charge beyond what they normally charged me for a cable calibration. Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] FW: [PSES] Pre-Amp mounted to antenna
I have used these in the past, with excellent results. MiniCircuits Model ZFBT-4R2G+, 3 SMA ports, 10 MHz-4200 MHZ (I used them in the 30 MHz to 2 GHz range), currently $60 each, stock. Ed Price WB6WSN Chula Vista, CA USA From: Brent DeWitt [mailto:bdew...@ix.netcom.com] Sent: Tuesday, March 15, 2016 9:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Pre-Amp mounted to antenna Not exactly "turn key", but Mini-Circuits will sell you connectorized bias Ts and DC blocks that will get the job done. Hope that helps, Brent DeWitt Milford, MA From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Tuesday, March 15, 2016 1:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Pre-Amp mounted to antenna Greetings. I'm looking for a low noise Pre-Amp for Radiated Emissions 30Mhz to 1Ghz (or higher) with a gain of 20-30dB; but here's the catch. I want it to mount directly to the "N" connector on my BiLog Antenna and be powered by a downstream Power Supply box that sends DC down the coax. Just like how TV Antenna pre-amps work. Does anyone know of a turn-key over the counter product like this that is available? I know such a design can have great benefits and be plagued with troubles such as reflections so I know it has to be done right and done well. Any information would be most helpful. Thanks in advance. The Other Brian - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Recommendations for DC-DC converter
Scott: I didn’t want to drop names about vendors, but Vicor has been my favorite for smart power supplies since I crashed into the same problem (on a smart bomb system around 1990) that you are now seeing. Vicor made commercial and MIL grade units, and they even offered an auxiliary module (called maybe a filter or power factor correction module) that met Army ground RE102 limits. Unfortunately, this auxiliary module was almost the same size as the whole converter, and you needed to mount both modules physically close to each other. I would imagine that other vendors have addressed this, and maybe somebody now puts it all into one brick. The point is, you and your client are probably not power supply design experts, so trying to find fixes for this power supply problem issue is likely not going to be as cost-efficient as getting a more costly yet MIL compliant power supply from your vendor (who really IS a power supply expert). Whenever I had the opportunity (and when designers would listen), I would suggest that the system designers get a real sample of the power modules from each of the vendors that they might be considering, and I would give them all a quick RE102 comparison. It was instructive (for all of us) to see how some modules would just barely squeek by the limit, and how others had much lower emissions. The system designers could then use this info to add to their overall design risk analysis. (It was also a good time to discuss the importance of a dB, as in “hey, this brick is a full 1.8 dB under the limit at the 5th harmonic, so we don’t have any worries about this model!”) BTW, on the system I mentioned, the system designer paralleled about 10 identical Vicor power supplies on a single power source bus. Then, he used each power supply enable logic line to only turn on whatever power supply was needed at any given moment. This considerably reduced power consumption, and eliminated relays or power switching semiconductors. I was really impressed by elegant trick (although sometimes I’m easily impressed). Ed Price WB6WSN Chula Vista, CA USA From: S Drysdale [mailto:sdd...@gmail.com] Sent: Thursday, February 25, 2016 6:58 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Recommendations for DC-DC converter Hi Ed, I believe you hit the nail on the head, figuratively. The problem is the use of a commercial DC-DC converter that is not meeting the required specification. The product and components must fit in a tight space, and spacing is extremely tight, so there is limitations on the external components we can add to filter this. This is the main problem we are running into with the current DC-DC converter, and I think a different DC-DC converter may require substantially less external filtering, or hopefully none at all. I have found gaia and vicor power imply some degree MIL-STD compliance, but I was hoping for manufacturer or product recommendations from those familiar with the concern. Best Regards, Scott Drysdale, OOO - Own Opinions Only http://ca.linkedin.com/in/scottdrysdale On Wed, Feb 24, 2016 at 4:22 PM, Ed Price <edpr...@cox.net> wrote: Scott: First, can we assume that the converter itself has already been successfully tested to RE102? If you are trying to use a commercial converter in a MIL environment, you may be starting at a big disadvantage. Some converter vendors offer an auxiliary active filter module, so get the vendor involved in your problem. The RE problem is probably not originating from radiation directly from the converter case, but from radiation from cabling connected to the converter. You may be able to decrease common mode currents with external ferrites or inductance, twisted pair power feeds may help and you should carefully review the mounting of the converter to the platform frame. Ed Price WB6WSN Chula Vista, CA USA From: S Drysdale [mailto:sdd...@gmail.com] Sent: Wednesday, February 24, 2016 11:41 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Recommendations for DC-DC converter All, My client has a very tight imposed limit for radiated emissions. Let's assume MIL-STD RE102 army ground. We are exceeding emissions caused by the DC-DC converter. Shielding is difficult in this application, and something we would like to avoid.Space requirements are an issue, and we think it may be easier to switch the module altogether. Input 48Vdc, Output is 12Vdc, 1.7A (or ~20W). Size is somewhat important, where smaller is better, but meeting this radiated emission limit is essential. Any recommendations? Best Regards, Scott Drysdale https://www.linkedin.com/in/scottdrysdale OOO - Own Opinions Only - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org>
Re: [PSES] Spectrum analyzer and noise floor
Not wanting to sound like too much of a dinosaur, but back in the 1960's and early 70's, emission data was acquired by slowly tuning a receiver across the frequency range while listening to headphones and watching a meter. You would record the frequency and amplitude at several frequencies per octave, or more if you were feeling charitable, and also record any uniquely "interesting" emission peaks. When you were finished acquisition, you might have several pages of tabular data (perhaps 75-100 frequency / amplitude data pairs). Then, you could go back to your desk and break out your correction data, a set of graphs for each of the parameters of cable loss, gain flatness, bandwidth variation, pre-amplifier gain, antenna factors and maybe filter attenuation (nothing was flat in those days). Typically, you might have 5 of these variables, so that meant writing down (5 x 75) 375 numbers on your data sheet. Then, you added up the raw amplitude and all factors for each frequency and entered that corrected amplitude. Next, you used the limit of the standard to visually interpolate and enter a limit value for each measurement frequency. And lastly, you compared the amplitude value to the limit value, and entered the over-limit values if necessary. And, if this was a very formal test, you often had to break out that old pre-printed multi-cycle logarithmic graph paper and plot the corrected data and the limit. Data correction took as long, or longer, than data acquisition. I dread to think of the error budget! The first automation that I encountered was a box using a variable speed motor and a flexible speedometer cable connected to the tuning knob of a receiver. You would set a "reasonable" scanning speed and connect an analog plotter to plot detector amplitude versus scan progress (or the Volts/MHz receiver output if you had a very advanced receiver). In this case, you would make a master plot with a derived limit (as Ken Javor described), then make photocopies of that master for the working measurement plots. We have come a very long way in 40 years. Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Tuesday, February 23, 2016 5:13 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Spectrum analyzer and noise floor I agree. A modern machine adjusts the raw data or noise floor for any and all transducer/amplifier/attenuator factors, and if the transducer factor is not flat, neither will be the adjusted noise floor. The only reason we do things this way is an "embarrassment of riches" in processing power. Absent a digital controller, the sane way to take data would be to adjust the limit for the transducer factors and arrive at an adjusted limit in terms of dBuV, or dBm. Consider the number of computations involved in adjusting a thousand data points across a screen for the transducer factors, vs. a simple flat or log-linear limit and transducer factors that only need be reentered at the next frequency at which they have changed by some set amount from the last frequency, such as 1 dB, or 0.5 dB. The adjusted limit represents orders of magnitude less computation, plus one can reverse engineer an adjusted limit if one knows the transducers in use, whereas adding factors to a signal above noise renders this impossible. Ken Javor Phone: (256) 650-5261 _ From: "McDiarmid, Ralph" <ralph.mcdiar...@schneider-electric.com> Reply-To: "ralph.mcdiar...@schneider-electric.com" <ralph.mcdiar...@schneider-electric.com> Date: Tue, 23 Feb 2016 16:42:47 -0800 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Spectrum analyzer and noise floor I would like to explain to a colleague why the noise floor on a SA does not look flat as it sweeps across a given frequency range after antenna factors, cable factors, external gain and external attenuation are programmed into its display function. I think it breaks down to these fundamental points: 1. the SA receiver has noise in its attenuator, mixer and filter circuits (say -80 dBm, and maybe flat within a limited frequency range) 2. the external amplifier has some noise too, but its gain lowers the noise floor created by #1 (also flat within a limited frequency range) 3. the cables have losses which are frequency dependant, and those can be entered as loss factors into the SA (shapes the noise floor a little and those losses raise the noise floor) 4. the antenna has a gain which is frequency dependant with several dB of hills and valleys across its usable frequency range (that really shapes the noise floor more than 1, 2 or 3 above) 5. noise floor shape caused by #4 is the mirror image of the antenna factor vs frequency Is that a decent summary? . Ralph McDiarmid Compliance Engineering Residential/Commercial Solar Business Schneider Electric D +1 (604) 422 2622 x62622 E ralph.mcdiar...@s
Re: [PSES] Spectrum analyzer and noise floor
Ralph: That's a workable explanation for the variation from flatness. Those who spend a lot of their time acquiring emission data get very accustomed to the shape of the corrected noise floor, and any variation from expected is a reason to stop the test and examine everything that is going on in the signal and the data processing paths. However, there is a problem with your statement #2. A pre-amplifier is chosen primarily for it having a first stage which has a Noise Figure lower than that of the input stage of your spectrum analyzer. You could well have a pre-amp with a small-signal gain of 35 dB and a noise figure of 1 dB, but if you put that pre-amp onto a spectrum analyzer that has a noise floor of -15 dBuV, you will not be able to see emissions of -50dBuV at the input of that pre-amp. Regardless of pre-amp gain, the Minimum Discernable Signal through the pre-amp and SA system will be limited by the pre-amp's 1st stage Noise Figure. You can prove this, without any math, just by getting a signal generator that puts out say 60 dBuV. Now add another 60 or so dB attenuation on the signal generator output, the idea to be able to apply a very smal signal to your SA. Now, put the pre-amp into the circuit and see what happens to the SA amplitude. Then, begin reducing the signal generator amplitude while noting the SA response. This will show you where the Minimum Discernable Signal fades into the pre-amp Noise Figure. Perhaps Ken or Ghery can give us a more elegant mathematical description of this effect. Ed Price WB6WSN Chula Vista, CA USA From: McDiarmid, Ralph [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Tuesday, February 23, 2016 4:43 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Spectrum analyzer and noise floor I would like to explain to a colleague why the noise floor on a SA does not look flat as it sweeps across a given frequency range after antenna factors, cable factors, external gain and external attenuation are programmed into its display function. I think it breaks down to these fundamental points: 1. the SA receiver has noise in its attenuator, mixer and filter circuits (say -80 dBm, and maybe flat within a limited frequency range) 2. the external amplifier has some noise too, but its gain lowers the noise floor created by #1 (also flat within a limited frequency range) 3. the cables have losses which are frequency dependant, and those can be entered as loss factors into the SA (shapes the noise floor a little and those losses raise the noise floor) 4. the antenna has a gain which is frequency dependant with several dB of hills and valleys across its usable frequency range (that really shapes the noise floor more than 1, 2 or 3 above) 5. noise floor shape caused by #4 is the mirror image of the antenna factor vs frequency Is that a decent summary? . Ralph McDiarmid Compliance Engineering Residential/Commercial Solar Business Schneider Electric D +1 (604) 422 2622 x62622 E <mailto:ralph.mcdiar...@schneider-electric.com> ralph.mcdiar...@schneider-electric.com 3700 Gilmore Way Burnaby BC Canada - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Free Stuff
I have been trying to thin my hoard of essential treasures, and I have excavated a set of In Compliance Annual Compendiums which I am offering gratis to anyone interested. Specifically, I have the following years: .1987-2003 .2005 & 2006 .2010 & 2011 You can track the development of regulatory issues and maturing standards and see the state of the art hardware over the past 30 years. The whole set would be about 25 pounds shipped weight, 18 shelf-inches, 22 volumes. I would prefer to give them as a set. Email me off-list. Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Is your company doing enough to ensure adequate EMC complia nce?
OTOH, I was always uneasy with the term “compliance” because to me, compliance is a coercive, one-way street. You are expected to comply, without any negotiation; comply or suffer the consequences. You comply, but there is no business incentive to excel. This is not a free market, not capitalism as it should be. I’m not saying that Compliance is pure evil, just that over-emphasis on compliance can yield stultification, restraint of trade and terminal boredom. Ed Price WB6WSN Chula Vista, CA USA From: Doug Powell [mailto:doug...@gmail.com] Sent: Saturday, January 16, 2016 10:54 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Is your company doing enough to ensure adequate EMC complia nce? In generic terms Compliance is indeed nothing more than adherence to a set of rules. I once debated legal council at a company who wanted exclusive use of the term. I pointed out how this term is used in finance, medical, transportation, product safety, EMC and legal circles. Given a bit more time I'm certain I could come up with a list nearly as long as your arm. This one reason why I personally prefer the term Compliance Engineer. It is unique to this business sector. Among my peers, I like to be more specific and mention product safety engineer or EMC engineer. All the best, Doug Douglas E Powell doug...@gmail.com https://www.linkedin.com/in/dougp01 From: Brian Gregory Sent: Saturday, January 16, 2016 11:24 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Reply To: Brian Gregory Subject: Re: [PSES] Is your company doing enough to ensure adequate EMC complia nce? Ah yes, I recall a conversation with a bright one from Garrad Hassan about a mutual customer. He was establishing their compliance with GH's established financial qualifications for an undisclosed analysis. I picked on the distinction rather quickly and had to clarify to him what compliance meant to me, representing an NRTL. Colorado Brian -- Original Message -- From: Scott Aldous <0220f70c299a-dmarc-requ...@ieee.org> To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Is your company doing enough to ensure adequate EMC complia nce? Date: Fri, 15 Jan 2016 10:11:52 -0800 As is made somewhat more clear in this article <http://www.fcpablog.com/blog/2015/11/9/sec-we-protect-compliance-officers-except-when-we-prosecute.html> (linked to by the original), this has nothing to do with technical product compliance but is about securities compliance <https://en.wikipedia.org/wiki/Securities_regulation_in_the_United_States> . Sloppy use of the term "compliance" with no explanation of the specific meaning. Scott (am I the "other" Scott?) just made a similar point... I will post anyway. On Fri, Jan 15, 2016 at 9:52 AM, Brian Gregory <brian_greg...@netzero.net> wrote: If you read the article (and others) it can be read either way. The blog's purpose is to give Compliance Officers tools, reference information and background as to what is going on. That the SEC is getting involved in Compliance investigations indicates to me increased scrutiny of companies' compliance issues. As a technical issue, this appears to me to be bureaucratic overreach at the least, since SEC and DOJ aren't safety organizations like OSHA. I think out-of-compliance issues should be (1) safety based and (2) customer sourced. SEC or DOJ get involved when there's a user-related problem or clear malfeasance (altering of documentation, unsubstantiated claims, etc.), which are covered under existing laws. As I see IEC regulations leaning more towards risk management/aversion, I get the feeling that standards organizations are also contributing to this overreach by trying to solve problems, via regulation/standardization that haven't been proven yet to be problems in the actual marketplace of people, customers and products. If you've been involved in any STP's, it's hard to avoid the feeling that there are some making hay out of increased regulatory oversight, including many ways that help consultants more than end users. Colorado Brian -- Original Message -- From: "gdstuyvenb...@yahoo.com" <058ee1229c70-dmarc-requ...@ieee.org> To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Is your company doing enough to ensure adequate EMC compliance? Date: Fri, 15 Jan 2016 13:29:10 + Ken, wasn't suggesting increased government regulation, rather useful tips for our own consideration. Gary Stuyvenberg Thompson Consulting _ From: Ken Javor <ken.ja...@emccompliance.com> To: EMC-PSTC@LISTSERV.IEEE.ORG Sent: Thursday, January 14, 2016 10:59 PM Subject: Re: [PSES] Is your company doing enough to ensure adequate EMC compliance? “Last week was a good one for the compliance profession. “ Could not disagree more. This is bi
[PSES] Compliance
Ken: I disagree that we are getting off-topic. Most threads here are issues of regulatory compliance, although not always the little segment of compliance related to electromagnetics. We have branched out to include compliance in safety, workplace management and health. Although we may have to do many dissimilar things if the area of compliance is electromagnetics or securities, the techniques of compliance (planning, ensuring, reporting, documenting, lines of authority) are probably inherently the same. Perhaps there's a brotherhood of compliance workers, all unknown to each other. To paraphrase Steinbeck: "Ma, wherever they's some Regulatory Agency beating on some poor company, I'll be there!" Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Sunday, January 17, 2016 8:10 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Is your company doing enough to ensure adequate EMC complia nce? We are getting off-topic here, but I can't let this one go without comment. Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Fwd: [PSES] Current probe for CM currents
I would add a caution to Ken's comment about common mode cable currents creating RE. Yes, the CM currents certainly do create RE, but you need to probe the cables at several intervals to understand those current paths. It is not immediately obvious that all CM current flowing on a cable at one end of a cable does not necessarily flow at the other end of that cable. Especially where cables are bundled, or where they pass closely along a chassis or structural member, there are possibilities for that current to couple off of the cable. The current flow will follow the impedances, both at the ends and at other fortuitous nodes. This is one of the reasons that a ferrite absorber might work much better at one position along a cable than at another position and also why RE might be dependent on something as obscure as cable bundle tightness. Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, January 15, 2016 8:53 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Fwd: [PSES] Current probe for CM currents I think it is important to not lose sight of the original query that started this thread. The query was about whether placing a current probe around a cable perturbed the current to be measured. There is no doubt that radiated emissions can originate within an equipment enclosure separately from driving common mode currents on a cable, but that wasn't the query. In fact, the poster was probing cables within a large rack (enclosure) looking for a source within an enclosure. Ken Javor Phone: (256) 650-5261 _ From: Bill Owsley <00f5a03f18eb-dmarc-requ...@ieee.org> Reply-To: Bill Owsley <wdows...@yahoo.com> Date: Fri, 15 Jan 2016 07:26:08 + To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Fwd: [PSES] Current probe for CM currents If you can measure common mode noise on a cable, you have a problem from the port !! Note the world famous Ott's math on this effect in his 1st edition. Might be in his 2nd too. I have used both e-field and h-field (current clamp) at the same time. We are engineers so figure out how I did that! And since some of the work is below 30 MHz, I have also added a loop antenna for a 3rd measurement. My approach is if I find any emission, locally, near field, bench stuff, that varies by position over the area of the product, then I have a problem. E-field scan,using a o'scope probe. H-field scan usually using a personally built small loop, and any other sort of scan, conducted or radiated, that I can make up at the moment. I work for a homogeneous field in the scans over the area of the product. My assumption is that if I find a homogeneous field, then there are no or low emission gradients which can equate to a field at a distance. So get creative, and redundant, by different methods for measuring the emissions. Ironic, I am good at mashing all emissions, and then they hand me an intentional radiator and ask that I don't kill the fundamental. What ? You mean I have to pick what to mash, and what not to mash? Ok, so I caught on quick enough to keep the job. ps. I suffer from not being able to use a leaky enclosure. I don't get any shielding for the products. Cable shielding that is bogus terminated, but at the low frequencies of interests, it works. Then I have to deal with the higher frequencies, the harmonics !!! Plastic covers and pcb and cables up to 15 KW or more of digital BS to make an analog signal. And then 'normal' digital signals for the ADC circuits all in the middle of this. Management is like, we have done it this way for over 25 years and so we are not changing it now. It works (I have to make it work) so don't change anything. Sucks to be me - but I do like a challenge. _ From: Ken Wyatt <k...@emc-seminars.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] spacex EMC tst engr job
Yes, that 50 WPM typing requirement disqualifies me too. I only type with two fingers, and even that skill is degraded when I need to use one finger for signaling. Ed Price WB6WSN Chula Vista, CA USA From: McDiarmid, Ralph [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Thursday, January 14, 2016 2:41 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] spacex EMC tst engr job I though this funny that one of the preferred skills is, "Able to type at a rate of at least 50 wpm" I think my mom could do 60 wpm in about 1950 on a manual typewriter. I think I can do about 40 wpm on a good day on a keyboard; 50 would be take some training and dedication. ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: "Brian O'Connell" <oconne...@tamuracorp.com> To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 01/14/2016 01:57 PM Subject: [PSES] spacex EMC tst engr job _ Saw this on the SpaceX web site. <http://www.spacex.com/careers/position/8459> http://www.spacex.com/careers/position/8459 damn, makes me wish that my specialty is EMC. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] 208 split-phase?
When I had that same task, I just bought a several kW Variac, connected it across the 208 VAC phase of a 3-phase feed, and used the Variac to increase the needed 5% or so. A big fan for the Variac can be cheaper than buying a really big Variac. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Brian O'Connell [mailto:oconne...@tamuracorp.com] Sent: Wednesday, October 21, 2015 12:48 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] 208 split-phase? Brian, Any significant impedance differences between these two supply configurations? Brian Sr Burrito Quality Control Engineer -Original Message- From: Kunde, Brian [ <mailto:brian_ku...@lecotc.com> mailto:brian_ku...@lecotc.com] Sent: Wednesday, October 21, 2015 12:34 PM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] 208 split-phase? I've never heard of a Utility Company providing 208 "split-phase". I have heard the term "208 split-phase" many times from our customers who claim to have this but in reality what they have is 208 3-phase wired into a 230V split-phase receptacle but only using 208 Phase to Phase with the Grounded Neutral. In our EMC lab, we do not have a true 220 split-phase so we use 208 with a grounded neutral. It is the closest thing we have to test 220 volt household appliances like ranges, ovens, microwaves, and dryers. We know it is not exactly the same but close. The Other Brian -Original Message- From: Peter Tarver [ <mailto:ptar...@ieee.org> mailto:ptar...@ieee.org] Sent: Wednesday, October 21, 2015 10:22 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] 208 split-phase? Good morning. There are oftensmall, legacy grids that you come across or hear about. I was recently told that some areas of the Northeast US have a 208 V, split-phase power system to some residences and small businesses. Still 180° phase-to-phase and presumably 104 V phase-to-Neutral. A specific area cited was "around Boston." Has anyone heard of or directly experienced this voltage system? Is it split-phase or was I misinformed and it's from a WYE connected transformer? Peter Tarver <mailto:ptar...@ieee.org> ptar...@ieee.org - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Microwave Amplifier
Here's an interesting little amplifier for 1 GHz to 11 GHz, with a 1.5 dB NF, draws 55 mA @ 5VDC, has 16.5 dB gain and an output of +18 dBm. Cost of the amplifier chip, on a prototype board, with 50 Ohm SMA input/output is $920 from Digi-Key. You could slap this in a little can with a battery and have a decent little pre-amp. Also, it says that its input and output are DC blocked, so you could even feed 5 VDC power down the coax. http://www.digikey.com/product-search/en?mpart=122826-HMC753LP4E <http://www.digikey.com/product-search/en?mpart=122826-HMC753LP4E=1127> =1127 Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] FW: [PSES] QP Detector - how to confirm accuracy & functionality
I believe that you can fully characterize the response of a QP detector by exposing it to a regimen of varying pulse widths and repetition rates. I used an HP-85650A external Quasi-Peak detector module (perhaps obsolete now), and here is HP's advice on the response characteristics for compliance with CISPR QP requirements: (Sorry, but list rules prevent me including the graphic. Anybody who would like to see HP's advice should email me directly and I'll send it to you off list.) I would assume that whatever current hardware you may be using must have some similar manufacturer's procedure for verifying the detector response. Of course, this does not establish absolute calibration for a CW signal, it simply demonstrates the relation of the QP detector to CW. Ed Price WB6WSN Chula Vista, CA USA From: McDiarmid, Ralph [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, October 19, 2015 5:00 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] QP Dectector - how to confirm accuracy & functionality Pulse duty ratio must be important too. I've often seen Pk measurements 5 or 6dB higher than QP. ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: Ken Wyatt <k...@emc-seminars.com> To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 10/19/2015 03:49 PM Subject: Re: [PSES] QP Dectector - how to confirm accuracy & functionality _ Hi Chas, Might be a bit pricy, but the AET USDS spherical comb gen has a pulsed feature that can check QP detectors. See my review: http://www.edn.com/electronics-blogs/the-emc-blog/4439682/Review--The-AET-US DS-spherical-harmonic-comb-generator Alternatively, if you can find an RF generator with pulse modulation, set it to 2 Hz and the comparison between the sine (CW) signal with peak detection and the pulsed signal in QP detection should be about 3 dB lower. Put another way, a sine wave signal with either peak or QP detection should read the same. With the pulsed signal the QP detector will read lower by about 3 dB. Ken ___ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 56 Aspen Dr. Woodland Park, CO 80863 Phone: (719) 310-5418 <mailto:k...@emc-seminars.com> Email Me! | <http://www.emc-seminars.com/> Web Site | <http://design-4-emc.com/> Blog <http://www.edn.com/blog/The-EMC-Blog> The EMC Blog (EDN) <http://www.emc-seminars.com/Newsletter/Newsletter.html> Subscribe to Newsletter <http://www.linkedin.com/in/kennethwyatt> Connect with me on LinkedIn On Oct 19, 2015, at 3:17 PM, Grasso, Charles <charles.gra...@echostar.com> wrote: Hello, Does anyone know of a gizmo or procedure that provides a standard signal for checking the accuracy of a QP detector in a SA? Thanks in advance!! Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) <mailto:3032042...@vtext.com> 3032042...@vtext.com (e) <mailto:charles.gra...@echostar.com> charles.gra...@echostar.com (e2) <mailto:chasgra...@gmail.com> chasgra...@gmail.com - This - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] SV: [PSES] Stricter limits than legal (CISPR11, IEC, etc,) Where?
The ARRL (American Radio Relay League, the US national ham radio club) has its own shielded enclosure and EMI lab. They have recently tested agricultural "grow lights" and have found almost every sample exceeds CE limits (some by almost 60 dB). After no success in solving this condition with the manufacturers, the ARRL has submitted their data to the FCC and asked for recalls of the offending models. Hams also report problems with the switching power supplies associated with commercial LED light bulbs. It will be interesting to see how the FCC reacts to a request to recall large volumes of consumer products; as far as I know, the last time the FCC was faced with controlling a large and uncaring market was back in the CB radio era of the 1970’s, and that didn’t work out very well at all. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: CR [mailto:k...@earthlink.net] Sent: Thursday, October 15, 2015 6:27 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] SV: [PSES] Stricter limits than legal (CISPR11, IEC, etc,) Where? On 10/14/2015 10:25 PM, Ted Eckert wrote: > > It is fairly common to run into issues where one product causes > interference where it shouldn’t. > > <http://www.compliance-club.com/archive/old_archive/Bananaskins.htm> > http://www.compliance-club.com/archive/old_archive/Bananaskins.htm > Do note that the archive only covers up to 2004. I've had occasion to cite entry 3. I suspect the relative scarcity of reported problems may be ascribed to proactive standards that are revised when the need becomes evident; one reason I got a contract in 2004 -- and why it was extended. Those of us who are Amateur Radio operators will have perhaps gotten involved in the myriad issues of new technology versus existing. I filed comments in the FCC's rulemaking on BPL (UK:PLT/PLC), which agency in the past has acted as if it had gotten orders to ignore some kinds of complaints -- a non-technical issue, eh? Some complaints answer the "why margin?" question, if possibly for a different reason than why we sometimes want it. About 15 years ago, residents of a New Jersey neighborhood started complaining about hearing a local AM station (really local: 10KW in the middle of the development) on their answering machines and telephones.The odd thing was that this apparently coincided with its switch from an "Easy Listening" music format to Korean language evangelism (I suspect a power increase as well). In any case, when the customer ordered equipment for that neighborhood he could (and IMO should) have considered proximity of pole-mounted power and other wiring to a high power RF source not anticipated by standards-writers. Cortland Richmond - - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Arc flash to earthed parts
As the appliance is a toaster, could the switch area have been contaminated by carbonized bread particles and/or burnt residue (raisins, glaze drippings)? This might account for the length of arcing, although you would think that good design would include a shield to keep such residue away from the contacts. Rich, would you talk a little about reforming of the switch contacts by the molten metal? If I were to imagine that I was looking at the center of a contact (along the axis of the arc), the current should set up a circular magnetic pattern. So, are you saying that the molten metal is "swept" around in a circle until it cools to the solid state? And just for fun, how many microseconds might it take for the molten metal to solidify? Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Richard Nute [mailto:ri...@ieee.org] Sent: Thursday, October 01, 2015 11:12 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Arc flash to earthed parts Hi Scott: When a switch opens (at something other than the zero-crossing), an arc is created and molten metal of the contacts is likely. (In fact, some contact designs use the molten metal to re-form the contacts.) The molten metal is accelerated (at right angles to the current direction) by the magnetic field. What is unusual is the length of the arc -- 1 inch. And, that the arc was from the switch contacts to the earthed parts. The current through the arc to the earthing conductor can be sufficient to trip the RCD. One hypothesis is that the current in the contacts created an excessive amount of molten metal which allowed the arc to also go through the molten metal droplets to the earthed metal. This would explain both the metal on the earthed part and the arc. Excessive contact heating could be caused by contact resistance being high (but not too high). Based on your description, I would hypothesize that the switch contact resistance was high; the switch is worn out, or has inadequate ratings. I don't know of any standard that would address this issue. The situation is analyzed by science and engineering, and appropriate changes to the construction to prevent recurrence. Good luck and best regards, Rich > -Original Message- > From: Scott Xe [ <mailto:scott...@gmail.com> mailto:scott...@gmail.com] > Sent: Wednesday, September 30, 2015 11:22 PM > To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG > Subject: [PSES] Arc flash to earthed parts > > Dear Members, > > I recently encountered a symptom on a toaster. When > turning off by pressing the quit button, there was an arc > flash from the mains switch contacts to earthed parts > where the separation greater than 1 inch apart in air > occasionally. The mains contacts have a sign of carbonisation on the > open/close contact points and > melted in a small area of the contact leaf. The switch > and the earthed parts are inside the plastic case without > the access by the users. It may trip the RCD during arc > flash. In addition, there was vaporised copper layer on > the earthed part. It did not have immediate danger to > the user and definitely not a good product. How should we categorise > this type of fault and is there any > reference standard for it? > > Thanks and regards, > > Scott > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Soci
Re: [PSES] Unexplained High Fallout of Power Supplies
Just a thought about contactors. Any mechanical contactor will allow some arcing as the contacts open. Further, in a 3-phase contactor, not all phases will actuate at the exact same time. At a given instant, you might have one phase open, another arcing and the third still a solid conductive path. Modeling sounds daunting. An electronic contactor should have fewer problems, but I wonder, in the example of a 3-phase electronic contactor, do all three phases get switched at once or is there some delay scheme to allow each phase to switch at its own zero-crossing time? Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Wednesday, September 23, 2015 5:33 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Unexplained High Fallout of Power Supplies John, Very interesting. We'll have to keep this in mind. We do have a dual pole contactor in the furnace circuit but the furnace also has a SSR for phase control. The contactor only opens and closes when the SSR is open (no current). The harmonic emissions from the phase control is why we have the large RF Line Filter. Thanks for the information. The Other Brian -Original Message- From: John Barnes [mailto:jrbar...@iglou.com] Sent: Tuesday, September 22, 2015 11:53 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Unexplained High Fallout of Power Supplies Brian, How is the furnace shut off? If you are using a contactor between the main line filter and the furnace, a phase line might open when it is carrying high current. The inductance of the line filter will try to keep this current flowing, generating a very-high kickback spike at the *output* of the line filter. Or, since the contacts in the contactor are unlikely to open/close at exactly the same time, a common-mode choke in the line filter can act as a transformer putting noise on the open phase(s) if only 1 or 2 phases are connected to the load. Some years ago, Bill Kimmel and Daryl Gerke wrote about a case where a 3-phase product had a contactor between a line filter and the load, which generated horrendous Conducted Emissions noise every time the contactor opened or closed, because of this transformer action. The solution was to replace the common-mode choke with 3 separate chokes, one for each phase line. John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, Master EMC Design Eng, SM IEEE (retired) Lexington, KY http://www.dbicorporation.com/ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not perm
Re: [PSES] 3115-PA & 3116C-PA Horn Antennas with Pre-amplifiers
Grace: Putting the pre-amp directly on the antenna is the best way to use a pre-amp, and the calibration data is what tells you if the system is good enough for what you need. Assuming you can trust the manufacturer’s data, look at the sensitivity (the minimum discernable field strength) that the combination of the antenna design and the pre-amp design yields. Of course, the noise floor is determined by the pre-amp’s first stage. Remember that you still will have to adjust for cable loss between the pre-amp output and your analyzer input. Be cautious about overloading the pre-amp, both in-band and out-of-band (just because the 3115 is a 1 GHz to 18 GHz antenna doesn’t mean that it also isn’t a 300 MHz antenna; it is, it’s just a poor 300 MHz antenna). Lindgren cautions you about that. I wonder how the amplifier handles fast pulsed or transient RF? I’m surprised that the manufacturer provides data only for the combination of the antenna AND pre-amp; I could often want to use the antenna without any pre-amp. If I sent this out for periodic re-calibration to an antenna cal lab, I would request antenna factors for the bare antenna and the antenna plus pre-amp. In fact, unless you are digging for the last few dB of sensitivity, it’s good practice to not use the pre-amp. Always try for simplicity in measurements. Remember that you always pay for bandwidth with sensitivity. Sure, it’s nice to cover 1-18GHz with one antenna, but I found those broadband antennas often were very inefficient at their band edges. My choice was to use a 3115 style antenna only from 1-12 GHz, and then switch to a K-band traditional pyramidal horn for 12-18 GHz. The 3115-style antenna AF starts to climb badly above about 15 GHz. (I always used octave-band horns above 18 GHz, so I don’t have any experience with the 3116-style antennas. However, the same cautions apply.) Before I would buy a broadband antenna and pre-amplifier, I would study what’s available by using several antennas to cover that range. True, this slows you down, and that is also money, but only you can assign what that means to your decision. BTW, that’s a honking big external box for the pre-amp. I certainly hope that the box shields the pre-amp from any possible stray RF pickup. Lindgren vaguely mentions an “AC-DC power supply” and that tells me that the big box doesn’t have an internal battery. Well, I can picture a wideband, K-band pre-amp about the size of a ceramic postage stamp, so Lindgren must use that box for something (maybe they need that area to dissipate the heat). And remember that you will be tied to that power pack, so that means an extra wire snaking up to your antenna. There likely will be some times when that extra dangling cable could cause you some measurement issues (like worrying how a strong 300 MHz field might couple into the pre-amp via its DC power cord). It also makes field use of the antenna a problem (unless maybe you build yourself a battery pack). Lastly, how do you do a head-end validation of the measurement system? Do you plan to face the new antenna into some standard emitter, or do you plan to inject a signal into the pre-amp input? I didn’t see if Lundgren uses an SMA, N or something exotic between the antenna output and the pre-amp input; you might need a couple of coax adapters. Ed Price WB6WSN Chula Vista, CA USA From: Grace Lin [mailto:graceli...@gmail.com] Sent: Sunday, September 20, 2015 3:45 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] 3115-PA & 3116C-PA Horn Antennas with Pre-amplifiers Dear Members, Does anyone have experience using the 3115-PA and 3116C-PA? http://ets-lindgren.com/3115-PA http://ets-lindgren.com/3116c-PA More specifically, does the amplifier work good with the antenna? The design eliminates a cable between the antenna and the preamplifier. Thank you very much and I look forward to hearing from you. Best regards, Grace Lin - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org
[PSES] Complaint-Driven Immunity
To paraphrase Monrad and John: "The only justification for regulations is consumer complaints." Does anyone have any experience in filing a consumer complaint with their applicable national agency? Was it easy to find the place to enter your complaint? Did you get the impression the agency was simply trying to get you to go away? Did you feel as though your input was going to a null-bucket? Did you receive any follow-up? Was the process something reasonable for an average consumer? In short, does "no complaints" really indicate no problems? Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Tuesday, September 15, 2015 11:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF Common Mode Immunity Test Question In message <cy1pr03mb14701aee786ef1ef0a0689e994...@cy1pr03mb1470.namprd03.prod.outlo ok.com>, dated Wed, 16 Sep 2015, Ted Eckert < <mailto:ted.eck...@microsoft.com> ted.eck...@microsoft.com> writes: >As such, I am taking the lack of visible complaints for a possible lack >of the problem of interference. The *only* justification for emission limits and immunity requirements is complaints of interference. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] Complaint-Driven Immunity
John: I was thinking more about how the evidence of problems is chewed through an official bureaucracy. Specifically, how much of a barrier is put up to Joe Consumer when his computer flutters? If the regulatory agency makes it hard to register a complaint, or discards complaints for multiple bureaucratic whims, then how do spec writing groups even know there is a problem? For instance, in the USA, no sane person accepts the official data about inflation or unemployment rates. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, September 16, 2015 12:00 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Complaint-Driven Immunity In message < <mailto:000e01d0f0af$afa53fd0$0eefbf70$@ieee.org> 000e01d0f0af$afa53fd0$0eefbf70$@ieee.org>, dated Wed, 16 Sep 2015, Richard Nute < <mailto:ri...@ieee.org> ri...@ieee.org> writes: >In short, does ?no complaints? really indicate no problems? > It indicates no problems prominent enough to come to attention. This is not liked by hard science but it's the way the world wags. Do you want your taxes spent on pursuing non-compliant products that no-one has found defective? > >Carl Sagan: ?Absence of evidence is not evidence of absence.? Yes, this is hard science and no-one in EMC circles denies it. But applying it to emissions or susceptibility that no-one notices enough to complain doesn't make economic sense. -- OOO - Own Opinions Only. With best wishes. See <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] RF Common Mode Immunity Test Question
Dennis: The rationale that you don’t need consumer electronics with a modicum of immunity works only for you, because you are what I would call an expert customer. You have the knowledge to ameliorate immunity problems, but most of the population does not have this capability. Ed Price WB6WSN Chula Vista, CA USA From: dward [mailto:dw...@pctestlab.com] Sent: Monday, September 14, 2015 8:20 AM To: 'Ed Price'; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] RF Common Mode Immunity Test Question I for one would never want the US to get into this arena. Too much regulation in the US as it is. Don’t need more and don’t want more. I’ll decide what is best for me, not the government. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. From: Ed Price [mailto:edpr...@cox.net] Sent: Saturday, September 12, 2015 1:41 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF Common Mode Immunity Test Question John: Unfortunately, American consumer electronics has no E-field immunity requirement. The only help a consumer gets is that little paragraph of legalese that advises you to re-orient your device and move further away from emitters. OTOH, most consumer equipment design which takes emission compliance into account will also yield reasonable immunity levels. My personal experience indicates that most immunity problems with consumer electronics is not a design problem but a reliability problem. As an example, last year a friend asked me to repair his semi-pro mixer board (used in a church environment); he had problems “everywhere” with distortion, low gain and external RF susceptibility. However, the mixer board was fine; it was his patch cords that were horribly abused and leaky. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Saturday, September 12, 2015 11:47 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF Common Mode Immunity Test Question In message < <mailto:FCA549BE3ECF9D4CB8CB8576837EA48920AF42@ZEUS.cetest.local> FCA549BE3ECF9D4CB8CB8576837EA48920AF42@ZEUS.cetest.local>, dated Sat, 12 Sep 2015, "ce-test, qualified testing bv - Gert Gremmen" < <mailto:g.grem...@cetest.nl> g.grem...@cetest.nl> writes: >A Ham never can be a source of interference, by definition (if they >respect their limits- in more than one way). It is clearly not true, given the unlimited lack of immunity exhibited by some products. Immunity isn't even controlled in the Americas. > >To me an amateur is not a HAM, but that is a matter of language I >suppose. Yes. 'Amateur' is the larval form. (;-) > >My example showed a (spiced up) example of lack of immunity in a >professional audio installation , that due pragmatic testing, too >cables with average screening properties Was it definitely due to cables? Much professional PA equipment is none too good on immunity. And there are far too many installations that don't exclusively use balanced lines. > -- OOO - Own Opinions Only. With best wishes. See <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For
Re: [PSES] Getting 2 emails for many posts on the forum - is it just me?
John: Probably much further than 111 million miles. I'm very hopeful that any decent alien race will have finagled the speed of light limit. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Monday, September 14, 2015 11:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Getting 2 emails for many posts on the forum - is it just me? In message mailto:cP12fcBAA==@blueyonder.co.uk> cP12fcBAA==@blueyonder.co.uk>, dated Mon, 14 Sep 2015, John Allen < <mailto:john_e_al...@blueyonder.co.uk> john_e_al...@blueyonder.co.uk> writes: >I started noticing this happening a few days ago, and it has been >consistent all today for posts from US contributors, but there seems to >be about a 2 minute gap between the 1st post and the 2nd post - but >that does not seem to be happening from UK/European contributors, where >I am getting only 1 post. > >Anyone have any idea why? US posts are being monitored and relayed by aliens on an asteroid 111,160,000 miles away. You read it here first. -- OOO - Own Opinions Only. With best wishes. See <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] RF Common Mode Immunity Test Question
Gary: True, the FCC is essentially still following the Communications Act of 1934 in its scope. However, telegraph rates aren't so important anymore, while the issue of consumer electronics immunity certainly is. We expect our laws and regulations to evolve to address the important issues of the day, junking the obsolete and helping with new conflicts. Immunity problems may manifest themselves as product quality issues (fitness for use, truth in advertising) or safety issues (inadvertant activation, erratic reliability, failure to respond), so maybe the FCC shouldn't be the lead agency. OTOH, immunity control is technically so closely related with established FCC emission regulations (and our industry that helps enforce them) that I don't see it making any sense to get another authority involved. Agency cooperation isn't unheard of; for example, the FCC and FAA share requirements for radio tower marking, lighting and location. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Gary McInturff [mailto:gary.mcintu...@esterline.com] Sent: Monday, September 14, 2015 11:30 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF Common Mode Immunity Test Question IMO - The FCC was commissioned with protecting the public airways only - a far different scenario than in the EU. As such they worry about emissions coming from any unintentional or intentional radiator that would be detrimental to the public airways recivers or transmitting equipment. They were never set up or intended to protect the general public - even the CB and Ham radio stuff was to protect the public communications and not our neighbors TV. Although proper design, frequency allocation and usage would cut down on that type of interference. They do mention immunity but only in so much as to let you know that properly operating public communications equipment could cause problems - and the consumer should deal with it because the FCC has no authority to mandate it for non- public telecommunications equipment. Whether it should be granted that power or not is the discussion of the minute I suppose. -Original Message- From: John Woodgate [ <mailto:j...@jmwa.demon.co.uk> mailto:j...@jmwa.demon.co.uk] Sent: Monday, September 14, 2015 10:45 AM To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF Common Mode Immunity Test Question In message <sn1pr12mb07357121e3850ada9346ec6380...@sn1pr12mb0735.namprd12.prod.outlo ok.com>, dated Mon, 14 Sep 2015, Rodney Davis < <mailto:rodney.da...@mitel.com> rodney.da...@mitel.com> writes: >Hi guys, in simple English.. the FCC does state in section >15.17 Susceptibility to interference..., you are responsible for >reducing the susceptibility for receiving harmful interference. Who is 'you', and how does anyone know what level of immunity is 'enough' without immunity standards? -- OOO - Own Opinions Only. With best wishes. See <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
Re: [PSES] RF Common Mode Immunity Test Question
John: Unfortunately, American consumer electronics has no E-field immunity requirement. The only help a consumer gets is that little paragraph of legalese that advises you to re-orient your device and move further away from emitters. OTOH, most consumer equipment design which takes emission compliance into account will also yield reasonable immunity levels. My personal experience indicates that most immunity problems with consumer electronics is not a design problem but a reliability problem. As an example, last year a friend asked me to repair his semi-pro mixer board (used in a church environment); he had problems "everywhere" with distortion, low gain and external RF susceptibility. However, the mixer board was fine; it was his patch cords that were horribly abused and leaky. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Saturday, September 12, 2015 11:47 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] RF Common Mode Immunity Test Question In message < <mailto:FCA549BE3ECF9D4CB8CB8576837EA48920AF42@ZEUS.cetest.local> FCA549BE3ECF9D4CB8CB8576837EA48920AF42@ZEUS.cetest.local>, dated Sat, 12 Sep 2015, "ce-test, qualified testing bv - Gert Gremmen" < <mailto:g.grem...@cetest.nl> g.grem...@cetest.nl> writes: >A Ham never can be a source of interference, by definition (if they >respect their limits- in more than one way). It is clearly not true, given the unlimited lack of immunity exhibited by some products. Immunity isn't even controlled in the Americas. > >To me an amateur is not a HAM, but that is a matter of language I >suppose. Yes. 'Amateur' is the larval form. (;-) > >My example showed a (spiced up) example of lack of immunity in a >professional audio installation , that due pragmatic testing, too >cables with average screening properties Was it definitely due to cables? Much professional PA equipment is none too good on immunity. And there are far too many installations that don't exclusively use balanced lines. > -- OOO - Own Opinions Only. With best wishes. See <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < <mailto:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:sdoug...@ieee.org> sdoug...@ieee.org> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> dhe...@gmail.com> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
[PSES] Dimmable LEDs
I recently bought several Cree 815 lumen lamps with Edison style bases as replacements for some compact fluorescent lamps (which were replacements for incandescent lamps). Anyway, the Cree lamps have an internal switched mode constant current power supply to adapt the 120 VAC 60 Hz clean sine wave mains power to DC for the LED array. This SMPS probably can accept some pretty distorted power and yet hold the LED load at proper current. However, I also have a duty cycle electronic dimmer on this circuit, creating a delayed turn-on (on both half cycles) sine wave. Interestingly, the Cree SMPS somehow tracks the amount of sine wave delay and lowers the LED current so as to mimic how an old incandescent lamp would dim. I'm curious how the Cree SMPS manages this, so does anyone have a link to an explanation of how a dimmable LED SMPS works or even what the circuit looks like? Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] International EMF Scientist Appeal
This has all the hallmarks of irrationality. It starts with it's killing us and it's getting worse, then moves on through save the children to conspiracy theories and suppression of evidence. While some of their points (prudent avoidance) are valid, I don't agree with any call for strong action. BTW, have you ever met any of the petition signatories? Personally, they lost me when they started the petition by addressing the UN Secretary as His Excellency. Ed Price WB6WSN Chula Vista, CA USA (still not dead after 55 years of intense RF exposure) Letter that appears to be designed to enable more UN/WHO influence over EMC standards. http://www.emfscientist.org/index.php/emf-scientist-appeal www.emfscientist.org/index.php/emf-scientist-appeal Dunno what to think about this stuff. Much of their basis comes from 15 to 20 year old studies, at least one of which seems to have been recently discredited Personally, prefer to keep my phone close to head - keeps the brain warmer. And am looking at buying some land near the Sunrise HV distribution line (500kV) so that we can bask in SLF 'radiation'. Whom is the bigger idiot - myself or these scientists? Brian - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Murata EMIFIL BNX022
Amund: The filter can be installed with either side facing the EUT; however, this is the decision of the equipment designer. (He may want more attenuation from LINE to EUT or vice versa, so he decides which way he prefers. OTOH, he may have just put in whatever filter that physically fit the volume he had.) You test it as it’s delivered to you. BTW, that 35dB figure is probably measured in a 50 Ohm system, so the actual filtering will be dependent on the impedance of the EUT and the LISN (which may go very strange above 10 MHz). Ed Price WB6WSN Chula Vista, CA USA From: Amund Westin [mailto:am...@westin-emission.no] Sent: Monday, May 18, 2015 1:39 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Murata EMIFIL BNX022 From datasheet: Insertion Loss Characteristics 1-1000MHz is 35dB. Seems that this loss is measured as noise is approaching from the power supply side. The EMIFIL BNX is not a symmetrical filter, so for conducted emission purpose, do we have to switch BNX022 input / output to maintain the 35dB loss? B.regards Amund - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] EMC and Data Center
Monrad: My idea of treating the data center as one big box seems to be consistent from an engineering viewpoint, but may not be acceptable to the lawyers who approve the work. It seems to me that, once you establish that you have a bi-directional loss of maybe 100 dB due to a shielded enclosure, you can add as many sort-of-similar radiating elements as you like into that environment without changing what leaks out. Added gadgets do not affect the shielding integrity (so long as the shield doesn't melt). Of course, this would require an engineering analysis of each new added gadget (for similarity to previous gadgets and for risk of compromise of the shield integrity). So maybe this path would be more trouble than alternatives. Ed Price WB6WSN Chula Vista, CA USA From: Monrad Monsen [mailto:monrad.mon...@oracle.com] Sent: Thursday, May 14, 2015 9:36 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] EMC and Data Center Hi Eugene, I'll take a stab at answering your questions. Should I test just one rack of a type on the turn table for RE? How many racks should be tested together for CE? Or just one? I test the worst-case maximum configuration that can be mounted in a single 19-inch rack. FCC would refer to this as a composite system [47CFR15.31(k) in http://www.gpo.gov/fdsys/pkg/CFR-2014-title47-vol1/pdf/CFR-2014-title47-vol1 -sec15-31.pdf]. While FCC talks about composite systems having separate enclosures connected by wire, I do not believe one needs to extend that to everything in an IS shop (or everything in the world) that is connected by wire. Hence, I stop at a more reasonable place of a single 19-inch rack. Generally, a single rack would have a couple of servers, couple of disk arrays, a couple of Ethernet and/or Fibre Channel switches, and the rest of the rack filled with disk arrays. What standards are to be applicable for this situation? FCC? Bellcore GR-1089? Both? More? Only FCC has the force of law, so this is the only one that is mandatory. However, your e-mail indicates that you intend to sell to telephone companies in USA, and some telephone company customers will only buy products that are NEBS compliant (GR-1089). NEBS would be a marketing requirement, not a regulatory requirement. Please note that you can sell non-NEBS verified products to telephone companies (even ATT and Verizon) if they plan to use it in their IS shop away from their telecommunications network control facilities, but you will be a step ahead of the competition if you did go ahead and get NEBS for those customers. Be forewarned that you need to check on a lab's accreditation to confirm they can test for NEBS, and some telephone companies also require the Verizon accreditation for the test labs with Verizon's extra requirements. Complying with NEBS will add cost to your products both in the testing and in the design. Again, this is a marketing decision. Ed Price adds an interesting discussion about treating the entire data center as a single product. I don't think this is practical from from a sales perspective because it would require doing on-site emissions testing every time the data center changes (installs extra equipment). Hope this helps. Monrad Monsen Disclaimer: Everything expressed in this e-mail are strictly my own opinions and are not necessarily those of any employer I work for. On 5/14/2015 1:42 AM, Ed Price wrote: I'm not an expert on this, but here's a starter. Shouldn't a data center be within an RF shielded enclosure, with power and signal ports bandwidth limited by filters and couplers? (Wouldn't the data I/O be fiberoptic?) A moderate enclosure should give you 80dB isolation from the environment, and physical isolation will add to that. You could consider the whole enclosure as one device. For RE, standing just outside the enclosure, I doubt you could even prove the data center internal systems were working. I'll let others add/correct this, but to me, a data center looks like a factory in a box, with its own dedicated power feed (not shared by residential or light industrial users) and can be treated as Part 18 ISM. I don't know what your client expects of you, but I think they should be concerned with self-compatibility of the various subsystems installed within that shielded volume. Will each rack of processors or routers have its own UPS? What interactions will happen with multiple UPS's connected in parallel, and what will be the RE environment among those racks? And if this equipment is all USA origin, what further assurances of RS can the vendors provide? Ed Price WB6WSN Chula Vista, CA USA From: Eugene Peyzner [mailto:epeyz...@sbcglobal.net] Sent: Wednesday, May 13, 2015 8:56 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] EMC and Data Center Dear experts, Could you please share your knowledge about a philosophical or logical approach to EMC testing of a data center. To simplify my question let's talk about just
Re: [PSES] Interference Caused by Microwave Oven
Old microwave ovens (like the one from 1988) were electrically quite simple; a relay applied AC power to a step-up transformer, and the secondary output was grounded (one side) and connected to a diode (other side). The diode allowed a low-capacitance HV capacitor to charge and the magnetron to produce RF output. It was a simple half-wave rectifier circuit. When the door safety switch open, the relay would drop out (anywhere along the AC sinewave), and the magnetron would continue to produce RF until the capacitor voltage dropped below the minimum magnetron excitation voltage. I can't recall magnetron current nor the capacitor size, but the decay was pretty darn fast. I wonder if the capacitor was large enough to sustain RF output through the negative half of the AC power? So, although electrical shut-down was quick, you have to take slack in the door safety switch mechanism into consideration. Best if the switch was linked to a safety latch, but not so good if the switch was sensing door position. New microwave ovens, more computer than appliance, and with a switching power supply, might have a larger HV capacitor, and thus longer decay time when being shut down. People who have built their own ham gear or have built lab equipment such as pulse generators, know the hazards of HV and interlock systems, but when your whole experience is built around 5 3.3 VDC equipment, RF door leakage may come as a big surprise. I think EMC engineers would be aware of this, but the issue is much more under the domain of safety. If nothing else, an EMC engineer should flag this to the safety guy for proper evaluation. Interestingly, many news sources quote the oven emission as 1.4 GHz which is very unlikely for a consumer oven. They didn't mention if the telescope was being used in the 2.4 GHz band (again unlikely), so I wonder if the telescope was being overloaded by the out-of-band 2.4 GHz oven fundamental, if the oven harmonics were to blame or if the telescope data-processing equipment was actually the victim. One story at least admitted that researchers were suspicious of the signals, as they only were a problem during working hours. Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Friday, May 15, 2015 8:55 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Hi All, I recently wrote an article on wireless interference, with microwave ovens being one source of that interference. Fortunately, the use cycle of microwave ovens is relatively short, so any interference is short-term. However, any leakage is certainly an issue for those standing nearby - maybe listening to popcorn, etc.? http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-inte rference--analysis--and-optimization In this article, I show a real-time spectral plot of microwave oven leakage at 12 inch distance from the oven. The peaks were around -20 dBm using a short rubber duck antenna on the Tek RSA306 analyzer. The leakage limit is 1 mW/cm^2 with a test load (water) and 5 mW/cm^2 without a test load (measured at 5 cm from the oven surface). I measured mine just now at 0.1 mW/cm^2 loaded and 0.5 mW/cm^2 unloaded. The Australian Government did a study on the subject in 2004 and includes some interesting background on the door interlock designs: http://www.arpansa.gov.au/pubs/emr/microwave.pdf Health Canada also did a survey of several new and used microwave ovens in the Ottawa area: http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/i ndex-eng.php Cheers, Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! mailto:k...@emc-seminars.com | Web Site http://www.emc-seminars.com | Blog http://design-4-emc.com/ The EMC Blog (EDN) http://www.edn.com/blog/The-EMC-Blog Subscribe to Newsletter http://www.emc-seminars.com/Newsletter/Newsletter.html Connect with me on LinkedIn http://www.linkedin.com/in/kennethwyatt On May 15, 2015, at 9:00 AM, Ken Javor ken.ja...@emccompliance.com wrote: My microwave oven used correctly interferes with wi-fi and Bluetooth, but with blue tooth if I bring the devices close together I can overpower the incidental oven radiation, right next to the oven. I can't do that with wi-fi at home, because of the fixed location of the wi-fi base station at the other end of the house from the oven. Obviously I can bring the wi-fi device closer to the base station and at the same time farther from the oven and make the problem go away, but that is hardly surprising. But the point of the news item was that it seemed the interference was tied to the oven door opening, which is problematic, at least to me. I don't buy the delay thing someone posited - I'm thinking that it is a switch activating a relay interrupting power to the magnetron, and that happens before any
[PSES] Oven Sinicism
Yes, it's Friday, so let's route all this into its own Sinicism thread! Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: dward [mailto:dw...@pctestlab.com] Sent: Friday, May 15, 2015 12:34 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Sinicism - a word made up from Latin for Chinese (sinicus) and Greek for belief, ideology or style (ism). Meaning - a Chinese method or style extended meaning - a certain negative belief about products made in China - of which may result in missing the good things. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, May 15, 2015 12:16 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven And I'm not disappointed. Ken Javor Phone: (256) 650-5261 From: John Woodgate j...@jmwa.demon.co.uk Reply-To: John Woodgate j...@jmwa.demon.co.uk Date: Fri, 15 May 2015 19:50:26 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002e01d08f35$4068c0f0$c13a42d0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: May your Sinicism not cause you to miss the good things in life. I'm not Chinese! And I'm not of the canine persuasion, which is what the word you aimed at originally alluded to. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] EMC and Data Center
I'm not an expert on this, but here's a starter. Shouldn't a data center be within an RF shielded enclosure, with power and signal ports bandwidth limited by filters and couplers? (Wouldn't the data I/O be fiberoptic?) A moderate enclosure should give you 80dB isolation from the environment, and physical isolation will add to that. You could consider the whole enclosure as one device. For RE, standing just outside the enclosure, I doubt you could even prove the data center internal systems were working. I'll let others add/correct this, but to me, a data center looks like a factory in a box, with its own dedicated power feed (not shared by residential or light industrial users) and can be treated as Part 18 ISM. I don't know what your client expects of you, but I think they should be concerned with self-compatibility of the various subsystems installed within that shielded volume. Will each rack of processors or routers have its own UPS? What interactions will happen with multiple UPS's connected in parallel, and what will be the RE environment among those racks? And if this equipment is all USA origin, what further assurances of RS can the vendors provide? Ed Price WB6WSN Chula Vista, CA USA From: Eugene Peyzner [mailto:epeyz...@sbcglobal.net] Sent: Wednesday, May 13, 2015 8:56 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] EMC and Data Center Dear experts, Could you please share your knowledge about a philosophical or logical approach to EMC testing of a data center. To simplify my question let's talk about just EMI testing for USA. A data center contains computer systems and associated components, such as https://en.wikipedia.org/wiki/Telecommunication telecommunications and https://en.wikipedia.org/wiki/Computer_data_storage storage systems, air conditioning, fire suppression and various security devices. Servers are mounted in https://en.wikipedia.org/wiki/19_inch_rack 19 inch rack cabinets. Some equipment such as https://en.wikipedia.org/wiki/Mainframe_computer mainframe computers and https://en.wikipedia.org/wiki/Computer_storage storage devices are often as big as the racks themselves, and are placed alongside them. Should I test just one rack of a type on the turn table for RE? How many racks should be tested together for CE? Or just one? What standards are to be applicable for this situation? FCC? Bellcore GR-1089? Both? More? Thank you for your time and help. Best regards, Eugene - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
[PSES] Toy Directive
I was at a symposium recently where hundreds of (strictly non-electrical or otherwise powered) puzzles and games were being rated (for aesthetics such as age level, fun and intellectual challenge). However, nobody at this event gave any consideration to the familiar regulatory compliance issues such as choke hazard, biological safety, stored energy or unintentional uses. I began thinking about this when I examined a very simple toy consisting of 16 equal ¼ diameter, 4 long polystyrene tubes strung in series on a thin bungee cord. The string of tubes can be torqued into forming many (over 200 claimed) stable wire frame three dimensional objects. I was sitting there, twisting this thing into cubes and polyhedrons, when I realized that it could also form a very credible slingshot! I then noticed a very prominent CE on the box. I wonder if anyone in our group has ever done a product compliance with the Toy Directive. Maybe my background in defense is showing, but it seems to me that only a great toy can stimulate, amuse, educate and also be converted to a weapon. Ed Price WB6WSN Chula Vista, CA USA - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] SV: [PSES] Germanwings crash
John: could those in the cabin area be provided with a system whereby, in cases where the cockpit gets taken over, it could allow them to communicate with the someone somewhere to alert them of the problems Hmm, like posting a sign on the bulkhead something like 1-800-gutentag? Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Allen [mailto:john_e_al...@blueyonder.co.uk] Sent: Wednesday, April 01, 2015 3:06 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] SV: [PSES] Germanwings crash John You do have a point - but, actually, there is a much wider one that IACO could consider: that is, in such cases, could those in the cabin area be provided with a system whereby, in cases where the cockpit gets taken over, it could allow them to communicate with the someone somewhere to alert them of the problems - but it would still not prevent the person still remaining in the locked cockpit to do whatever they want, unless a remote unlocking facility is incorporated. Again, maybe in the future, and then again subject to all the communications-related issues mentioned in my first post on this subject. -Original Message- From: John Woodgate [ mailto:j...@jmwa.demon.co.uk mailto:j...@jmwa.demon.co.uk] Sent: 01 April 2015 22:41 To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] SV: [PSES] Germanwings crash In message !!AAAYAEGjmYsMtGZAuvo7rFLQ++figAAAEIikrBPlu6RNlut8A mailto:ucpoOcBAA==@blueyonder.co.uk ucpoOcBAA==@blueyonder.co.uk, dated Wed, 1 Apr 2015, John Allen mailto:john_e_al...@blueyonder.co.uk john_e_al...@blueyonder.co.uk writes: you think they could conceivably operate consistent and reliable systems whereby a pilot says I need a cr*p, please open the cockpit door in 30s, and someone, somewhere, has to say OK, and do that? I'm sure that isn't what was meant. The ground control would operate only in exactly the Germanwings emergency case - lockout of an officer due to the other officer being mentally disturbed or having, for example, fainted and fallen on the switch. It does require the locked-out officer to be able to send a suitable Mayday, but that's not so difficult. Even so, I think my proposal for lockout being invoked only by both officers is simpler and possibly more reliable. -- OOO - Own Opinions Only. With best wishes. See http://www.jmwa.demon.co.uk www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to mailto:emc-p...@ieee.org emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas mailto:sdoug...@ieee.org sdoug...@ieee.org Mike Cantwell mailto:mcantw...@ieee.org mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: mailto:j.bac...@ieee.org j.bac...@ieee.org David Heald: mailto:dhe...@gmail.com dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to mailto:emc-p...@ieee.org emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas mailto:sdoug...@ieee.org sdoug...@ieee.org Mike Cantwell mailto:mcantw...@ieee.org mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: mailto:j.bac
Re: [PSES] Basic instruction in EMC and safety requirements for the non-professional
John: I beg to differ with you when you say that a conviction of technical superiority is a 50-year old dinosaur attitude . Do you recall a recent highly popular smartphone which provided an insanely excellent experience, but only if you held it the right way so as to not block its communication link? Further, we have accepted the software industry model that technical superiority trumps many aggravating features. A new set of proud lizards enters management every year. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Tuesday, March 31, 2015 2:54 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Basic instruction in EMC and safety requirements for the non-professional In message !!AAAYAEGjmYsMtGZAuvo7rFLQ++figAAAEGclIn6IPpdMlDLZ1 mailto:GnjPVEBAA==@blueyonder.co.uk GnjPVEBAA==@blueyonder.co.uk, dated Tue, 31 Mar 2015, John Allen mailto:john_e_al...@blueyonder.co.uk john_e_al...@blueyonder.co.uk writes: - unfortunately, the cost without a sale argument is prevalent, But since the cost is necessary for market entry, the real point is 'no sale without this cost'. and not only amongst the marketing men but also amongst some of the senior technical management because of their conviction that the technical superiority of their products will overcome any minor legal issues with problems in selling those products! That attitude was 'dinosaur-like' 50 years ago. -- OOO - Own Opinions Only. With best wishes. See http://www.jmwa.demon.co.uk www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Basic instruction in EMC and safety requirements for the non-professional
Brian: Yet it must be noted that Mr. Coyote never brought suit against the Acme Company, despite a long history on non-compliant and generally unsuitable products whose use often resulted in grave physical injuries. This would probably be counter-productive to Ken's quest. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Brian Oconnell [mailto:oconne...@tamuracorp.com] Sent: Tuesday, March 31, 2015 1:31 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Basic instruction in EMC and safety requirements for the non-professional Mr. Nute, As this is probably for management, respectfully suggest that the premier exposition for PHBs is none other than a reference to some Wile E. Coyote videos. This is well within the MBA attention span and their required level of understanding for product performance and conformity. Brian From: Richard Nute [ mailto:ri...@ieee.org mailto:ri...@ieee.org] Sent: Tuesday, March 31, 2015 12:57 PM To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Basic instruction in EMC and safety requirements for the non-professional Hi Ken: Oh, boy. EMC and safety requirements are a cost without a sale. That is what a VP of marketing told me. For the most part, management would prefer to keep the costs at a minimum. EMC, ROHS, and safety requirements are rules that the products must comply with in order to sell in various countries. 1) The requirements must be included in the design of the product. 2) Tests verify that the product complies with the requirements and determine whether the product can bear certification marks. 3) Marks applied to the product attest to compliance with the requirements. 4) For some countries, documents accompanying the product attest to compliance with the requirements. 5) Some countries and certification houses require factory inspection as a condition for marking the product. 6) Some certification houses require periodic factory surveillance. 7) The cost of compliance at our company is. The number of full-time employees in this activity is. I'm sure that you can amplify on any of these points if asked. Good luck, and best regards, Rich From: Ken Javor [ mailto:ken.ja...@emccompliance.com mailto:ken.ja...@emccompliance.com] Sent: Tuesday, March 31, 2015 10:39 AM To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Basic instruction in EMC and safety requirements for the non-professional Can anyone out there suggest either some texts or urls covering the subject matter for management at a higher level not interested in details? Especially as to impact on selling equipment outside a country's own borders. Thank you, Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to mailto:emc-p...@ieee.org emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas mailto:sdoug...@ieee.org sdoug...@ieee.org Mike Cantwell mailto:mcantw...@ieee.org mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: mailto:j.bac...@ieee.org j.bac...@ieee.org David Heald: mailto:dhe...@gmail.com dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe
Re: [PSES] LISN Bonding to Ground Plane for CEMI Testing per ANSI C63.4
Chris: I most recently used Solar LISNs; these models had an approximately 1/8 thick aluminum baseplate that extended beyond the front and rear edges. I could get completely adequate bonding resistance by just using a clamp to hold the aluminum flange snugly to the copper ground plane. I would just use a Scotch-Brite pad to shine up the copper and aluminum faces prior to attaching the clamps. I would verify my bond each day during long test programs, but after establishing an initial good setup, I never saw the bond degrade. I also used some LISNs which used a single ¼-20 bolt as the ground point. I used flexible copper straps with these LISNs, with the only caveat being that I used a large washer to clamp the strap against the LISN body instead of relying solely on the threaded stud. I was also very fond of the Keithley 580 Microohmmeter; it was stable and reliable, although the spring-loaded Kelvin probes were delicate. I bought various probe tips and alligator clips to make my own custom Kelvin probes; take a look at http://www.probemaster.com/ Ed Price WB6WSN Chula Vista, CA USA 1961 Amphicar 770 2001 Fleetwood Storm 31W 2008 Ford Explorer From: Chris Bramley [mailto:christopher.bram...@us.bureauveritas.com] Sent: Thursday, March 12, 2015 3:47 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] LISN Bonding to Ground Plane for CEMI Testing per ANSI C63.4 ANSI C63.4-2014 clause 5.2.2 requires a direct current resistance of less than or equal to 2.5 milliohms between the LISN being used for CEMI measurements and the reference ground plane. Is it possible to achieve this low level of resistance by simply bolting the LISN to the ground plane(after thoroughly cleaning the LISN and ground plane contact points)? I am looking for a solution that allows the LISNs to remain reasonably portable as they are regularly transferred between test sites. Also, what combination of Kelvin probes and milliohm meter works best to take quick, repeatable measurements of the resistance between the LISN and the ground plane? Christopher Bramley EMC Test Engineer I Bureau Veritas - Consumer Products Services Littleton Distribution Center 1 Distribution Center Circle, Suite 1 Littleton, MA 01460, USA 978.486.8880 x6135 christopher.bram...@us.bureauveritas.com This message contains confidential information. To know more, please click on the following link: http://disclaimer.bureauveritas.com; - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Ferrite Cores on cables and possible reduction
Chuck: I would delete that particular rule of thumb from my mayonnaise jar full of rules. 3 dB is easy to get with a ferrite on a high impedance data line at 800 MHz, but a lot harder to obtain at 37 MHz on a stepper motor drive line. Ed Price WB6WSN Chula Vista, CA USA From: Grasso, Charles [mailto:charles.gra...@echostar.com] Sent: Tuesday, March 03, 2015 9:38 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Ferrite Cores on cables and possible reduction Hello all, It is generally reported (at least as far as I can remember) that a ferrite bead clamped on a cable will provide - typically- only about 3db of improvement as a general rule. I am now in a position of looking for the source of that common knowledge .. Does anyone have such a reference? Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com (e) charles.gra...@echostar.com (e2) chasgra...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Used Screen Room?
FW: Pardon if this sounds too commercial, but you did ask. My first choice for RF enclosures, antenna ranges and modification/service work is Hi-Tech Services, run by Henry “Ozzy” Osgood. He is based in Ferndale, Washington, although he’s temporarily at an undisclosed location in Virginia. Ozzy is totally reputable and capable, and has done several enclosure jobs for me over the past 30 years, so give him a call at 360-220-5803 (or email ozziee...@aol.com) and fill him in on what you need. Spring has sprung The grass has ris, I wonders where My absorbers is? Ed Price WB6WSN Chula Vista, CA USA From: FW Miller [mailto:012cd6de8c7b-dmarc-requ...@ieee.org] Sent: Tuesday, March 03, 2015 10:59 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Used Screen Room? Ah, yes, Spring is in the air here on the Left Coast, with dreamy thoughts of an installation of a used screen room/anechoic chamber. Have any vendor recommendations for such used equipment? Many thanks, FW Miller - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Serrated head screws for grounding/bonding
I won't try to pose as an expert on electrochemical activities of bonded dissimilar metals, however, I have built a lot of non-deliverable jigs and test aids which had to function in really rotten conditions. There is some type of MIL approved coating (dare I call it a shellac or a varnish?) which works great on protecting the assembled stack of a ground/bond assembly. It has a relatively low viscosity (like light oil) and really likes to work itself into crevices. That said, for many projects, I have found that coating the assembly with liquid plastic (the red, viscuous goop sold at Radio Shack for coating handles on pliers, which air-cures to a very protective, flexible rubber layer) to work quite well. Just yesterday, I changed out an auto battery and coated the terminals with this goop. I have never had any other type of terminal protection work that well; it applies easily, a second layer is also easy, and it removes like a rubber glove. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Sunday, March 01, 2015 12:20 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Serrated head screws for grounding/bonding In message mailto:752831402.610104.1425186818324.javamail.ya...@mail.yahoo.com 752831402.610104.1425186818324.javamail.ya...@mail.yahoo.com, dated Sun, 1 Mar 2015, Bill Owsley mailto:00f5a03f18eb-dmarc-requ...@ieee.org 00f5a03f18eb-dmarc-requ...@ieee.org writes: ps. and use compatible metals that are less than ?? emf volts apart, Note that the table of contact potentials in some IEC safety standards does not relate to the real world but to lab conditions where no contaminants, particularly chlorides, are present. The connector industry has much more data on this subject, including the effects of contaminants, but it's not for publication. What this means is that any combination of metals or platings that isn't known from experience to be satisfactory should go through relevant environmental tests. -- OOO - Own Opinions Only. With best wishes. See http://www.jmwa.demon.co.uk www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Serrated head screws for grounding/bonding
Doug: I first learned about the non-intuitive value of metal displacement from the now almost forgotten technology of wire-wrap, and then I found it had been in use for quite a while on telephone push-down wire connectors. Both of those technologies yielded long-term reliability, so I can't see why that wouldn't work for star washers too. OTOH, there is still that possibility of a heavy fault current blasting away tiny point-contact conduction paths. Hmmm. Maybe commercial standards have been overly influenced by arguments of cost, as it's certainly cheaper to just use a serrated skirt bolt in place of an assembled stack of components. We might be in the land of maybe not the best, but good enough for us. BTW, the military system also emphasizes that you are not done when you torque the fastener; you still have to protect the assembly with some coating (like varnish or liquid plastic or paint). I suppose this is acknowledging the issues of joint capillary action and not being gas-tight. I never cease to be amazed at how many EMC questions depend on answers from mechanical engineers. Ed Price WB6WSN Chula Vista, CA USA From: Doug Powell [mailto:doug...@gmail.com] Sent: Saturday, February 28, 2015 9:18 AM To: Ed Price Subject: Re: [PSES] Serrated head screws for grounding/bonding Ed, The idea of not using a star washer for military use may be at odds with some of the international standards I use. I fully agree that clean non-painted surfaces are important but restrictions on the use of stars or serrated bolts may be the issue. From your mil-std quote and the description of flat smooth surfaces, it would seem that the goal of these statements is to achieve a high conductivity connection. For international standards work I am involved in doing the goal is to achieve adequate conductivity for safety even after years of non-current carrying operation. One of the issues with flat surfaces is corrosion control. The star washer is a way of biting into metal connections with an oxygen free connection. This cannot be guaranteed with smooth metal surfaces. I would be interested to hear other thoughts on this. Doug On Fri, Feb 27, 2015 at 7:47 PM, Ed Price edpr...@cox.net wrote: Constantin: The military practice is to never use a star washer or ribbed underside bolt to cut into a painted, plated or unknown surface to achieve a ground bond. I would show you a nice view of the fastener stack from the very old MIL-B-5087 Bonding standard, but the server does not allow graphics within posts, so we'll just have to imagine it. MIL-HDBK-1857 is much more current; it has a number of examples of bonding and says essentially the same thing: 3.2.6 Grounding requirements. A ground stud shall be provided on equipment. The ground stud shall provide the electrical ground connection to the chassis or frame and shall be mechanically secured to insure low resistance joints by soldering to a spot welded terminal lug or to a portion of the chassis or frame that has been formed into a soldering lug, or by use of a terminal by a screw, nut and lock washer. The ground stud shall be of a size to allow electrical connection of size AWG 10 wire. All hardware used for grounding or other electrical connections shall be made from copper or copper alloys. Terminal luge shall be tin plated or hot tin dipped. Paint, varnish, lacquer, etc., shall be removed from the vicinity of the fastening point to insure metallic contact of the two surfaces. Corrosion protection shall be provided for all ground connections. Internal or external lock washers shall not be used on any grounding or other screw type electrical connections. Lock washers shall not be located between the metal plate and terminal lug or other part being grounded, so as not to interfere with the full and direct contact between these two members. Neither locking terminal lugs nor self-locking nuts shall be used for grounding. Flat washers shall be inserted next to any part having insufficient contact area with its adjacent part. The way I read all this is that the military does not consider any ground or bond proper if it doesn't start out with surfaces prepared for good conductivity. If you have a painted chassis or box, you should either mask the intended ground location before painting, or remove that paint in a separate operation before assembly of the fastener stack. Maybe the commercial codes (NEC?) allow for fasteners which cut their own bond path (I see that a lot in appliances and residential wiring). Remember that I'm thinking of a bond as doing two things; first, providing a low-impedance RF path, and second, providing a low-impedance and high current path, so as to pass heavy fault current to allow protective devices to activate. I agree that multi-toothed star washers, when really torqued down, seem to do a good job of cutting through coatings and oxides; it's just that the military doesn't see that as good
[PSES] Serrated head screws for grounding/bonding
Constantin: The military practice is to never use a star washer or ribbed underside bolt to cut into a painted, plated or unknown surface to achieve a ground bond. I would show you a nice view of the fastener stack from the very old MIL-B-5087 Bonding standard, but the server does not allow graphics within posts, so we’ll just have to imagine it. MIL-HDBK-1857 is much more current; it has a number of examples of bonding and says essentially the same thing: 3.2.6 Grounding requirements. A ground stud shall be provided on equipment. The ground stud shall provide the electrical ground connection to the chassis or frame and shall be mechanically secured to insure low resistance joints by soldering to a spot welded terminal lug or to a portion of the chassis or frame that has been formed into a soldering lug, or by use of a terminal by a screw, nut and lock washer. The ground stud shall be of a size to allow electrical connection of size AWG 10 wire. All hardware used for grounding or other electrical connections shall be made from copper or copper alloys. Terminal luge shall be tin plated or hot tin dipped. Paint, varnish, lacquer, etc., shall be removed from the vicinity of the fastening point to insure metallic contact of the two surfaces. Corrosion protection shall be provided for all ground connections. Internal or external lock washers shall not be used on any grounding or other screw type electrical connections. Lock washers shall not be located between the metal plate and terminal lug or other part being grounded, so as not to interfere with the full and direct contact between these two members. Neither locking terminal lugs nor self—locking nuts shall be used for grounding. Flat washers shall be inserted next to any part having insufficient contact area with its adjacent part. The way I read all this is that the military does not consider any ground or bond proper if it doesn’t start out with surfaces prepared for good conductivity. If you have a painted chassis or box, you should either mask the intended ground location before painting, or remove that paint in a separate operation before assembly of the fastener stack. Maybe the commercial codes (NEC?) allow for fasteners which cut their own bond path (I see that a lot in appliances and residential wiring). Remember that I’m thinking of a bond as doing two things; first, providing a low-impedance RF path, and second, providing a low-impedance and high current path, so as to pass heavy fault current to allow protective devices to activate. I agree that multi-toothed star washers, when really torqued down, seem to do a good job of cutting through coatings and oxides; it’s just that the military doesn’t see that as good enough. Maybe another thing the military has against star washers is that, by cutting their own bond path, they are actually doing a small machining operation, and the paint and base metal micro-debris could be considered FOD. I can’t cite any prohibitions, but I can’t recall military products using any lock washers other than the split-ring style (not getting into locknuts here J). Hope this helps! Ed Price WB6WSN Chula Vista, CA USA From: Bolintineanu, Constantin [mailto:cbolintine...@tycoint.com] Sent: Friday, February 27, 2015 5:59 AM To: Ed Price Subject: RE: [PSES] Serrated head screws for grounding/bonding Dear Ed, I red your posting and I have a question: you specified “The washer is placed between the nut and the top face of the flat lug, never between the lug and the ground surface.” My question regards the correctness of the above underlined and highlighted statement in the light of penetrating the paint in a such design solution that you stated. In my opinion, the washer plays this role in almost each and every situation. Sure, I know that there are situations when it is not necessary to penetrate the paint etc. but generally speaking I think it shall. Could you please be so kind and comment on it? As well, there are situations when a lock washer shall be used in conjunction with a tooth washer and maybe you are talking about it within the above statement. Do you have a drawing showing the GROUND (PE) connection within a Class I appliance structure? Please accept in advance my many thanks for the clarifications. Sincerely, Constantin Bolintineanu P.Eng. iNARTE CERTIFIED ENGINEER Tyco Security Products Tel: +1 905 760 3000 / 2568 3301 Langstaff Road / Concord, Ontario, L4K 4L2 / Canada mailto:lmansillok...@tycoint.com cbolintine...@tycoint.com / http://www.tycosecurityproducts.com www.tycosecurityproducts.com From: Ed Price [mailto:edpr...@cox.net] Sent: February-26-15 12:25 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Serrated head screws for grounding/bonding Peter: The military doesn’t like that method. I think the primary reason is that the serrations form small point
Re: [PSES] Serrated head screws for grounding/bonding
Peter: The military doesn’t like that method. I think the primary reason is that the serrations form small point-contact connections, and, under heavy fault current, these little points will melt and/or vaporize. The military prefers a strap which terminates in a flat ring-lug, with the lug being clamped against the physical ground structure with a heavy nut and split-ring compression washer. The washer is placed between the nut and the top face of the flat lug, never between the lug and the ground surface. The purpose of the compresion washer is to maintain pressure of the lug against the ground structure. Ed Price WB6WSN Chula Vista, CA USA Good morning. I am reviewing the suitability of serrated head screws in grounding and bonding applications. I am aware that these screws are good at resisting vibration, but I've not seen them used for grounding and bonding purposes. I question this application since, while the serrations oppose loosening of the screw, they do not bite into the metal beneath the head and also seem unlikely to form a gas-tight connection, allowing degradation of the grounding/bonding interface over time. What are your opinions? Are you aware of any evidence of the reliability of an grounding/bonding connection using such screws? The screw will secure a wire, possibly with a crimp-on ring connector. (I also question the value of using a single toothed washer in these applications.) Regards, Peter L. Tarver This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message in error, please contact the sender by reply email and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to mailto:emc-p...@ieee.org emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas mailto:sdoug...@ieee.org sdoug...@ieee.org Mike Cantwell mailto:mcantw...@ieee.org mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: mailto:j.bac...@ieee.org j.bac...@ieee.org David Heald: mailto:dhe...@gmail.com dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Preamplifiers
Grace: It’s best to have your pre-amplifier right at the output of your transducer (antenna). This way, you can minimize losses ahead of the pre-amp (losses which can never be recovered regardless of pre-amp NF gain). This technique also results in a surprising advantage. If your try to buy a very wideband pre-amp, it will be very expensive. But, if your pre-amp is used with just one (or a couple of antennas), then you can buy several pre-amps. Oddly enough, several relatively narrow pre-amps can have better NF’s and still cost less than one magnificent wide badnwidth pre-amp. I took a quick look at Keysight, and it looks like the pre-amp you are thinking about starts at about $8000. Wow. For instance, I needed a low-noise pre-amp to help my biconical antenna (30 MHz to 200 MHz) and my double-ridged horn antenna (200 MHz to 1 GHz). I bought a HILNAV1 amplifier from Nuwaves Company for about $400: http://www.nuwaves.com/hilna/ This amplifier had a NF of about 0.8 dB and a nominal gain of 40 dB. Also very impressive 3rd order intercept and 1 dB compression figures. (Nuwaves sold me a custom model which was usable down to 30 MHz; their advertised low end is 50 MHz.) I removed its case and mounted it in a custom box that I could hang off the antenna coax connector. I also included a “bias T” device, so that I could eliminate batteries by feeding DC power down the coax from next to my spectrum analyzer (no concerns about battery life now). After a couple of evenings of work, I had a very decent pre-amp system ready to be formally characterized. I also bought some microwave pre-amps later, doing the same thing for my other horn antennas. The whole set of amplifiers was much less than $8000. I’ll send you my spec sheets on the Nuwaves amplifier, as I did some gain compression and linearity studies on that unit. You might be interested to see what kind of performance you can get for several hundred dollars. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Grace Lin [mailto:graceli...@gmail.com] Sent: Wednesday, February 25, 2015 8:07 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Preamplifiers Dear Group Members, I try to figure out the differences (from performance point of view) between an old preamplifier and a new preamplifier. Your comments and help are highly appreciated. An HP 8449B preamplifier was very popular 20 years ago. Its replacement is 83017A according to the Keysight webpage. Website information for these two models was copied and pastes to the bottom of this email for convenience. Page 11 of Agilent AN 1315 states: ... There are two important factors to consider when choosing a preamplifier: gain and noise figure. The noise figure (NF) of the preamplifier must be lower than the NF of the spectrum analyzer... It seems there are not much differences for the gain and noise figure between 8449B and 83017A. It seems there is a big difference for the gain compression. My questions are: 1) How does the role of gain compression play in the measurement? 2) Are there any other parameters to be consider when choosing a preamplifier? I did note a lot of spectrum analyzers and EMI receivers have a built in preamplifier. Thank you very much for your time and I look forward to hearing from you. Best regards, Grace Lin 8449B Microwave Preamplifier, 26.5 GHz http://www.keysight.com/en/pd-101909%3Aepsg%3Apro-pn-8449B/microwave-preamplifier-1-ghz-to-265-ghz?cc=USlc=eng http://www.keysight.com/en/pd-101909%3Aepsg%3Apro-pn-8449B/microwave-preamplifier-1-ghz-to-265-ghz?cc=USlc=eng Key Features Specifications • Sensitivity for MIL-STD radiated measurements • Noise Figure: 1.0-12.5 GHz - 8.5dB; 12.5-22.0 GHz - 12.5dB; 22.0-26.5 GHz - 14.5dB • Minimum Gain: 23.5dB • Gain Flatness: 1.0-26.5 GHz - ±4.5dB; 2.0-22.0 GHZ ±3.5dB • Gain compression: 1 dB for output signal of ≤ +7 dBm • Connector Type: ACP - 3.5 male Description The Keysight 8449B microwave preamplifier is a high-gain, low-noise preamplifier that provides additional sensitivity for any RF/microwave spectrum analyzer for detection and analysis of very low signals. The improved sensitivity can dramatically reduce measurement time. 83017A Microwave System Amplifier, 0.5 to 26.5 GHz http://www.keysight.com/en/pd-101780%3Aepsg%3Apro-pn-83017A/microwave-system-amplifier-05-to-265-ghz?nid=-32708.536880733.00cc=USlc=eng http://www.keysight.com/en/pd-101780%3Aepsg%3Apro-pn-83017A/microwave-system-amplifier-05-to-265-ghz?nid=-32708.536880733.00cc=USlc=eng Key Features Specifications Superior RF performance • Gain of more than 25dB • P1dB of more than 18dBm to 20GHz • Noise figure of less than 8dB to 18GHz,13dB to 26.5GHz (typ) Connectors Type • Rf connectors: 3.5mm(f) • DC Detector output
Re: [PSES] RS FSP Spectrum Analyzer
Grace: I would think that the fastest answer should have been asking your friend “why” regarding his assertion. Was he basing his advice on the FSP model specifically, or on spectrum analyzers in general? Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Grace Lin [mailto:graceli...@gmail.com] Sent: Monday, February 16, 2015 1:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] RS FSP Spectrum Analyzer Dear Members, Is anyone familiar with the RS FSP spectrum analyzer ( http://www.rohde-schwarz.com/en/product/fsp-products_63492-8043.html http://www.rohde-schwarz.com/en/product/fsp-products_63492-8043.html) and would like to share comments/experience? A friend advises me that this is not good for my purpose (taking data for regulatory compliance of wireless devices). I am looking/searching for justifications to request a new one. Thank you very much. Best regards, Grace Lin - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] SSL - shielded chamber
Just a guess, but since they have a lot of absorber material temporarily strung on the non-flight support structure, I think they are not doing RS but rather antenna pattern testing. You really don't need to do much high-level RS testing on a whole satellite platform, since the platform will be rather far away from any potential emitters during its operational phase. During the launch phase, the satellite is probably powered down, and the strongest local emitters will be vehicle command and telemetry, which are not very strong emitters either. Of course, the various RF ports will be bandwidth and amplitude proteted. If the platform was a vital national asset, I think I would be more concerned with a kinetic or laser attack instead of HIRF. That is an impressive facility (maybe 30' high by 50' wide), although it may not necessarily be a shielded enclosure; we may just be looking at an open alcove with a lot of absorber material. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Amund Westin [mailto:am...@westin-emission.no] Sent: Thursday, February 12, 2015 11:49 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] SSL - shielded chamber I was reading an article today about a new broadcast satellite that will go into space in April 2015. Manufacturer and designer is SSL located in Palo Alto. From the SSL web site photo gallery, we can see a huge shielded chamber. Anybody who know the dimensions of this room and what kind of field strength they can produce? Just curious ... http://sslmda.com/images/photo_gallery/index.html http://sslmda.com/images/photo_gallery/index.html #Amund - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
[PSES] Google Earth Pro Now Free
FYI: Google has now made their Google Earth Pro available for free (it used to cost $400 for a 1 year license, but demand is so low that it looks like they gave up trying to squeeze some money out of this version). Heres what the Pro can do that the non-Pro version cant: * Print images at 4800×3200; non-Pro is capped at 1000×1000. * Automatically import a few thousand addresses at once to be pinned on a map. You can create a club membership maps or special interest maps, like show every Wal-Mart in Manitoba. * Capture HD videos of whats on screen. * Measure distances/areas using lines, paths, polygons, circles, and more. Non-pro can only handle lines/paths. This is really handy if you want to measure real estate or estimate construction projects. All you have to do is go to https://geoauth.google.com/gev0/free_trial.html and fill out the registration form. Ignore anything about costs and buying and free trials. After filling out the form, Google will send you your key by email. Then, go to http://www.google.com/earth/download/gep/agree.html to start the INSTALL. Google Earth Pro will install onto your machine (if you have Google Earth already, it will preserve your preferences and locations) and automatically remove the old Google Earth. Totally painless and quick installation. Ed Price WB6WSN Chula Vista, CA USA 1961 Amphicar 770 2001 Fleetwood Storm 31W 2008 Ford Explorer - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Speaking of EMC Immunity
Cortland: .and I'm writing a memoir, yes I am. Remember to get your lawyer to verify statute of limitations first! Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: CR [mailto:k...@earthlink.net] Sent: Wednesday, January 28, 2015 12:49 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Speaking of EMC Immunity On 1/28/2015 3:19 PM, Rick Busche wrote: I was talking with an EMC engineer at our facility and he introduced me to a site called Banana Skins. This is a list of EMC immunity problems that should be considered for product design. Apparently complying with the standard (if there is one) can have rather disastrous results. As an example, a lady died as a result of EMC sensitivity between the warlike talkie in the ambulance and the heart machine. For your reading review: http://www.compliance-club.com/archive/old_archive/Bananaskins.htm http://www.compliance-club.com/archive/old_archive/Bananaskins.htm Lots of us here; I'm one and few of mine are in there. Do be aware that a good many of those Banana Skins were just High School Physics -- at least for an experienced military tech and longtime Ham Operator (guilty on both counts). Lots of fun. There was one time I got a whole SW engineering team to sit on wet seat cushions, and another I found a product problem by using a disconnected hot plate... certifiable Mad Scientist type, and I'm writing a memoir, yes I am. Cortland Richmond KA5S - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Design by committee disasters!
Remember that the LISN started out in the pre-semiconductor age, so LISN transients were much less of a danger. My major concern in using LISN's was that I was usually testing large military systems, and the test specimens were often rather buggy when they reached my lab. Unexpected modes and surprise shutdowns could be expected, so sudden 100% drops of current could create a dangerous transient. OTOH, the LISN should now be standardized with built-in measurement port protection. I would suggest that the design should have a serious high-pass filter (to minimize AC line harmonics from overloading the receiver) and transient limiting. Perhaps it should include a 3 dB attenuator; I think the traditional external 10 dB is a bit of overkill; it's nice to be able to note throw away any more sensitivity than is necessary. This protection might be a problem for anyone still doing injections through the measurement port (does anyone still do that). Ed Price WB6WSN Chula Vista, CA USA From: Doug Powell [mailto:doug...@gmail.com] Sent: Tuesday, January 20, 2015 4:59 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Design by committee disasters! I would agree as well. However, it is possible to put heavy filtering (capacitive) ahead of the LISN on the utility side to help absorb transients of external origin. If the EUT/DUT generates transients you could be in trouble. A simple 30 amp three phase contactor can cause this very problem. I've known many EMC engineers who have a habit of disconnecting the BNC at the input of the receiver only after energizing the EUT. Another problem with the 50 uH LISN is the high source impedance. When working with large power conversion equipment, it is often the case that the EUT presents a negative impedance load on the LISN. By definition an inductor in series with a negative impedance load is an oscillator at some frequency. Usually this frequency is the unity gain bandwidth of the closed loop control within the EUT. In years past, this was sometimes called a the input filter oscillation, Dr. David Middlebrook wrote several papers on the subject. I have personally experienced this problem on a 120/208V, 100 Amp three phase feed from a motor gen set. The resonances in the circuit cause the line voltages to Q up over +/- 500 VAC. Mainly because the motor generator added to the total inductance. I ended up putting 3 x 60 uF motor run capacitors in a delta configuration on the three phase lines on the line filters outside the test chamber. Inside we used a 5 uH LISN (CISPR 16) to do the measurements. Since then, I designed and calibrated a tastkopf voltage probe with an inherent 20 dB pad and this seemed to help protect my reciever very well. Thanks ~ doug On Tue, Jan 20, 2015 at 4:40 PM, Ken Javor ken.ja...@emccompliance.com wrote: Have to disagree with Doug, and do so with some trepidation. The original LISN was a 5 uH model designed for use on 28 Vdc power modeling an aircraft power-distribution system. Typical application was in a shield room utilizing filtered power, or at least a dedicated 28 Vdc power supply, so I can't see where the original design was fraught with danger. The same LISN was retained when aircraft went to ac power and used transformer-rectifier units to derive 28 Vdc power. Again, the application used filtered power. The same 5 uH LISN was used to evaluate conducted emission limits for office equipment leading up to the imposition of CE/RE requirements on non-antenna connected automatic data processing and office equipment in 47 CFR Part 15 back around 1980. The 50 uH LISN (to which Doug must be referring) was an attempt to keep the impedance closer to 50 Ohms over the range of the requirement, which at the time was 530 kHz to 30 MHz. I don't know if the ten-fold increase in inductance causes the problems to which Doug refers. Just that there wasn't a problem such as he describes in the original application. Ken Javor Phone: (256) 650-5261 tel:%28256%29%20650-5261 _ From: Doug Smith d...@emcesd.com Organization: D. C. Smith Consultants Reply-To: d...@dsmith.org Date: Tue, 20 Jan 2015 14:35:51 -0800 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Design by committee disasters! Hi All, Here are some thoughts of mine on two examples of design-by-committee in the EMC field which ended, in my opinion, a poor outcome: First, is the LISN (line impedance stabilization network), used in conducted emissions testing. I can't believe that a design would be included in standards that can easily source a 1000 Volt transient out of an innocent looking BNC connector intended for connecting to a spectrum analyzer. But that is what happens and many people have burnt out the input of their spectrum analyzer by connecting it to a LISN. The LISN design should not rely on people realizing the BNC output cannot be connected to a spectrum analyzer and putting in various protecting
Re: [PSES] FCC and immunity
Very broadly, the USA FCC regulates (both intentional and unintentionable) emitters and not receivers when it promotes that efficient use concept. That's the way that the underlying Communications Act is applied. OTOH, they sometimes do get into control of receivers when they specify technical content like blocked frequency bands, minimum signal-to-noise ratios and tuning requirements. If that type of regulation on receivers was acceptable, then I don't see any barrier to the FCC someday deciding to impose immunity regulations on communication receivers. However, it would be a philosophical reach to try to apply immunity to all electronic devices in general. Ed Price WB6WSN Chula Vista, CA USA -Original Message- From: Bill Stumpf [mailto:bstu...@dlsemc.com] Sent: Monday, January 19, 2015 8:51 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] FCC and immunity That is correct. The FCC does not regulate immunity of equipment. The FCC's function is to regulate interstate and international communications and promote the effective and efficient use of the frequency spectrum in US territories (and of course enforce FCC regulations!). Bill Stumpf D.L.S. Electronic Systems, Inc. 166 South Carter Street Genoa City WI 53128 Ph: 262-279-0210 -Original Message- From: Paasche, Dieter [ mailto:dieter.paas...@christiedigital.com mailto:dieter.paas...@christiedigital.com] Sent: Monday, January 19, 2015 10:33 AM To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] FCC and immunity It is my impression that FCC's would leave the immunity as a self-regulated requirement between manufacturer and user and just mentioned that the device must accept harmful interference. Sincerely, Dieter Paasche Advanced Product Developer, Electrical CHRISTIE 809 Wellington Street North Kitchener, Ontario N2G 4Y7 Phone: +1 519-744-8005 Ext 7211 http://www.christiedigital.com www.christiedigital.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] test errors
Doug: I took the liberty of severely editing you response, but I think the essence of your story is: “someone who goes to labs with no knowledge of how these tests are run are at a real disadvantage” I thought that the whole purpose of accreditation was to provide protection to the customer who is not an EMC expert and who cannot personally evaluate the quality of the EMC test services. Some 3rd party would police the test labs, and, to the extent that you trusted this 3rd party, you could trust the quality of accredited services. Sure, humans make mistakes, but the frequency of these mistakes should be statistically down in the same range as say, the number of times your test lab had a fire in the past year. However, since you know that it is necessary for a test services customer to be well-informed, then that’s evidence that the accreditation system is failing to deliver on its promise of a safe test environment. Perhaps accreditation can’t deliver what we expect, or perhaps we aren’t applying accreditation correctly. We have had about 35 years of EMC lab accreditation experience, and yet we still can’t, in good conscience, send an innocent customer through the process. Your solution is to make your clients smarter (which I don’t argue with at all), but what does that say of the efficacy and value of accreditation? Ed Price WB6WSN Chula Vista, CA USA From: Douglas Smith [mailto:d...@emcesd.com] Sent: Wednesday, December 17, 2014 10:28 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Brick power supplies and test errors (two topics) Hi Ed and the Group, Ed said: Did you create a write-up on what those errors specifically were, and how it happened that you noticed them in time to control them? I have not specifically written them up although I do tell them as war stories during my presentations. The biggies I remember were antenna placement, wrong antenna factors, and injecting more current in the conducted immunity test than was called for Other biggies are ESD test setups non-compliant (the lab test area) and the EFT test run with the clamp backwards. But someone who goes to labs with no knowledge of how these tests are run are at a real disadvantage. Recently I have rolled up a lot of this information in to a short web presentation I give to my clients so they can avoid these problems. Doug University of Oxford Tutor Department for Continuing Education Oxford, Oxfordshire, United Kingdom -- ___ _Doug Smith \ / ) P.O. Box 60941 = Boulder City, NV 89006-0941 _ / \ / \ _TEL/FAX: 702-570-6108/570-6013 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o | Email: d...@dsmith.org \ _ /]\ _ / Web: http://www.dsmith.org - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
