RE: IEC and EN standard relationships
I don't think anyone is dictating to ANSI that they must adopt IEC standards; however, both ESDA and IEEE Working Groups that I belong to have been told that they must harmonize with IEC wherever practical to do so... (ANSI adopts and publishes standards written by both ESDA and IEEE). (I think I said, ANSI and others have been told..., but really meant: Those writing standards for ANSI and others have been told) I suspect the pressure to harmonize comes down from ANSI with pressure from industry and (indirectly) from the government to adopt one set of international standards. A number of years ago, I attended a couple of meetings in New York and Washington that involved people from the US State Department, FCC, ANSI and the EU where the topic of discussion was reciprocity agreements where we would accept testing done by European Test Labs and Europe would accept testing done by US Labs. In order to achieve this, it seemed to be agreed that both would adhere to international standards as the basis of testing and test data I'm only guessing, but this was probably the beginning of the pressure on US standards development organizations to start the harmonization process. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com www.thermo.com/esd One Thermo, committed to integrity, intensity, innovation involvement From: Peter L. Tarver [mailto:peter.tar...@sanmina-sci.com] Sent: Tuesday, November 25, 2003 1:09 PM To: emc-p...@majordomo.ieee.org Subject: RE: IEC and EN standard relationships Mike - I'd like to understand who is making any such commands to ANSI, et al. While I understand there is a move (and has existed for some time) to migrate to the IEC format for standards, there is no entity that I am aware of issuing dicta to standards bodies in the US. ANSI -- ANSI sponsors the US TAGs to the IEC. ANSI Procedures for the Development and Coordination of American National Standards, §1.2.9, states that standards developers, if appropriate, base their standards on or consider the adoption of an ISO or IEC standard as an American National Standard. Reference is also made to ISO/IEC Guide 21 - Adoption of ISO or IEC Standards as regional or national standards. Similar text is found in ANSI Procedures for the National Adoption of ISO and IEC Standards as American National Standards, §1.0. Further information may be gleaned from ANSI's National Standards Strategy at http://www.ansi.org/standards_activities/nss/nss.aspx?menuid =3 or at http://public.ansi.org/ansionline/Documents/News%20and%20Pub lications/Brochures/national_strategy.pdf CSA -- SCC and CSA in Canada made formal statements that they intend to increasingly adopt IEC standards, where there are not conflicts with preexisting national standards and to work toward harmonization otherwise. CSA also is producing more standards in the IEC format. In fact, the ANSI committee membership that developed the Z136 series of standards that went into creation of the CDRH requirements, also sat (and probably continue to sit) on TC76. The differences are relatively narrow, but the marking logotype requirements for higher power lasers are taken another ANSI document. UL -- UL has also decided to adopt the IEC format for new and revised standards; I recall hearing so, but I'm not certain it's across the board (some standards committees' membership may resist this, for their own reasons, but if it doesn't change the content, it should be of little account). For both CSA and UL, Code and regulatory based national differences will continue to exist for the foreseeable future. CDRH -- The CDRH requirements long preexisted IEC 825, though the CDRH have, in Laser Notice 50, made it clear that IEC 60825-1 may be used for laser evaluation (with a somewhat more onerous certification marking requirement). It was expressed to me in 1997 by Jerome Dennis that the single largest barrier to thorough harmonization with IEC 60825-1 is related to Class IIIa and the behavior of the cornea at invisible wavelengths that the IEC refuses to take into account. It is important to keep in mind that the CDRH is a federal agency and its requirements must be published in the Federal Register to have the force of law. The Federal Register has been in its present format for decades and is unlikely to change any time soon. Regards, Peter L. Tarver, PE ptar...@ieee.org From: Mike Hopkins Sent: Tuesday, November 18, 2003 12:42 PM Info from outside the EU: In the US, ANSI and others have been told that any new standards written must be harmonized with the equivilent EN's or IEC documents (which are supposed to be the same but aren't always). From: Richard Hughes Sent: Tuesday, November 18, 2003 5:50 AM It has disappointed me
RE: Effective length of half wave dipole
I think the length of a 1/2 wave dipole in feet is basically 468/f(MHz) where the ratio of the length to diameter is very large (wire antennas in the HF region, for example). Making the diameter of the elements larger does two things: it reduces the overall length of the antenna and increases the bandwidth of the dipole. Sounds like a new product: and infinately short dipole useable over an infinately large range of frequencies! The only drawback is the diameter needs to be infinately large Oh well, can't have everything Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com www.thermo.com/esd One Thermo, committed to integrity, intensity, innovation involvement From: robert Macy [mailto:m...@california.com] Sent: Wednesday, October 29, 2003 1:54 PM To: kcc...@hkpc.org; emc-p...@majordomo.ieee.org Subject: Re: Effective length of half wave dipole From Dave Cuthbert's comments to me regarding a 1/4 wavelength dipole; he said that the current moves down the rod as the rod becomes thicker, which implies that the current distribution absolutely determines the effective length. Was that effective length or tuned length? hmm However, the whole thing may start with the conductivity of real life materials... Interesting to see the others' comments. - Robert - Robert A. Macy, PE .. m...@california.com 408 286 3985 . . . .. . . fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 On Wed, 29 Oct 2003 16:59:20 +0800 kcc...@hkpc.org wrote: Dear all I got confused with the effective length of a half wave dipole. 1) It is due to non-constant current distribution, or 2) It is due to the wave velocity in materials different from that in vacuum. What do you think which one is correct? Regards KC Chan This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: ESD for a dev lab work place
Not aware of any standards for ESD related to development; however, since new products will likely need to meet existing international and national standards, that would be the place to start In my experiance, engineering labs tend to use the standards (IEC 61000-4-2 being the most prevelant, but ANSI C63.16 is widely used in some U.S. industries), then raise the voltage, shorten the repetition rates and/or add many more tests per point. I think if you do some research, you'll find real ESD from people rarely gets to the 15kV level, but is typically faster (rise times) than the standards. (Think of how many times you've drawn a 1/4 inch arc off your finger anywhere except on the doorknob!) Most commercial ESD simulators have the capability of getting faster than standard rise-times, since to meet the requirements of 61000-4-2 things are done to slow it down. Anyway -- good luck, and I'd be interested to know if you find any standards I don't know about. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Systems One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation and involvement From: lfresea...@aol.com [mailto:lfresea...@aol.com] Sent: Thursday, October 16, 2003 10:52 AM To: emc-p...@ieee.org Subject: ESD for a dev lab work place Hi all, I've been asked to advise on ESD standards to impose on a development lab, not a manufacturing area. Are there such Standards? Thanks, Derek N. Walton Owner, L F Research EMI Design and Test Facility Poplar Grove, IL 61065
RE: SURGE testing, disturb. meas.
Not sure I understand the question Once the line is disconnected and the surge performed, one need only re-connect the line to determine if the port is still functional. I don't think it matters if the system keeps trying to resume the link -- in fact, I'd think that would be desirable... One concern brought up at the last meeting was a system that simply shuts down when the link is removed... Don't know what system actually does this, but it was brought up by someone in the telecom industry Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: GARY MCINTURFF [mailto:mcinturff3...@msn.com] Sent: Friday, September 19, 2003 7:13 PM To: Mike Hopkins; Konrad Stefanski; emc-p...@ieee.org Subject: Re: SURGE testing, disturb. meas. So is an ethernet line considered disabled when disconnected since it will drop the link (although it keeps trying to establish link and resume the idle data pattern? Gary - Original Message - From: Mike Hopkins mailto:michael.hopk...@thermo.com To: Konrad Stefanski mailto:kstef...@poczta.onet.pl ; emc-p...@ieee.org Sent: Friday, September 19, 2003 8:58 AM Subject: RE: SURGE testing, disturb. meas. There are couplers available from a number of manufacturers; however, none work at data rates much above 100kHz. For that reason, the current draft of 61000-4-5 revision 2 (not yet circulated) inlcudes the following -- keep in mind, it is an EARLY draft, but it will appear in a CD by the end of this year but with some clarification added regarding systems where disabling a port shuts down a system: Because of physical constraints, most coupling/decoupling networks are limited to handling data rates of up to about 100kHz. In cases where no adequate coupling/decoupling network is commercially available, surges shall be applied to the high-speed communication data port directly. First the port is determined to be functional, data lines are then removed, and the surge applied. After the surge, the data port must be re-tested to insure functionality. The EUT should be functional during the surge test with the port disconnected. The coupling method shall be selected as a function of the circuits and operational conditions. This has to be specified in the product specification. High speed communication lines such as ISDN or xDSL require low impedance in the decoupling network path in order to operate and an example of a suitable coupling/decoupling network is given in figure 13. This will only work for the 1.2/50us combination wave since the inductors will likely saturate with the longer 10/700us telecom waveform. The coupling/decoupling network referred to in a figure 3 is from an ETSI standard, but keep in mind, it will only work with very well balanced lines and with the 1.2/50us wave -- most telecom requirements for IEC specify using a 10/700us waveform. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Konrad Stefanski [mailto:kstef...@poczta.onet.pl] Sent: Friday, September 19, 2003 3:20 AM To: emc-p...@ieee.org Subject: SURGE testing, disturb. meas. Hello list. What is the simplest way to couple Surge pulses (EN 61000-4-5) with telecomunication lines? I haven't got proffesional coupling network. And the second question, what is the simplest way to measure voltage of disturbances from telecomunication lines without proffesional ISN? Thank You for answers. Konrad Stefanski PCBC SA Warsaw kstef...@poczta.onet.pl
RE: SURGE testing, disturb. meas.
There are couplers available from a number of manufacturers; however, none work at data rates much above 100kHz. For that reason, the current draft of 61000-4-5 revision 2 (not yet circulated) inlcudes the following -- keep in mind, it is an EARLY draft, but it will appear in a CD by the end of this year but with some clarification added regarding systems where disabling a port shuts down a system: Because of physical constraints, most coupling/decoupling networks are limited to handling data rates of up to about 100kHz. In cases where no adequate coupling/decoupling network is commercially available, surges shall be applied to the high-speed communication data port directly. First the port is determined to be functional, data lines are then removed, and the surge applied. After the surge, the data port must be re-tested to insure functionality. The EUT should be functional during the surge test with the port disconnected. The coupling method shall be selected as a function of the circuits and operational conditions. This has to be specified in the product specification. High speed communication lines such as ISDN or xDSL require low impedance in the decoupling network path in order to operate and an example of a suitable coupling/decoupling network is given in figure 13. This will only work for the 1.2/50us combination wave since the inductors will likely saturate with the longer 10/700us telecom waveform. The coupling/decoupling network referred to in a figure 3 is from an ETSI standard, but keep in mind, it will only work with very well balanced lines and with the 1.2/50us wave -- most telecom requirements for IEC specify using a 10/700us waveform. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Konrad Stefanski [mailto:kstef...@poczta.onet.pl] Sent: Friday, September 19, 2003 3:20 AM To: emc-p...@ieee.org Subject: SURGE testing, disturb. meas. Hello list. What is the simplest way to couple Surge pulses (EN 61000-4-5) with telecomunication lines? I haven't got proffesional coupling network. And the second question, what is the simplest way to measure voltage of disturbances from telecomunication lines without proffesional ISN? Thank You for answers. Konrad Stefanski PCBC SA Warsaw kstef...@poczta.onet.pl
RE: SURGE testing, disturb. meas.
Prices depend on the design: Some contain coupling and backfilter elements for 4 lines plus circuitry to allow coupling using either capacitors (still the preferred method in 61000-4-5) or arrestors. They also allow the addition of clamps of various levels to reduce or eliminate surges back to the auxillary equipment that is driving the line to be tested. Biasing of the clamping diodes allows virtually any clamping level Several resistor networks are also included to allow coupling to either 2 or 4 lines and still maintain the required 25 ohm loading for the 10/700us waveform and the 40 ohm loading required for the 1.2/50us waveform. A coupler like this is $5200 USD. Others contain a simple 0.5uF capacitor and a few resistors -- this coupler is available for about $1k. You get what you pay for. If anyone wants more details, let me know... and I'll answer outside the PSTC Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Bailey, Jeff [mailto:jbai...@mysst.com] Sent: Friday, September 19, 2003 9:42 AM To: emc-p...@ieee.org Subject: RE: SURGE testing, disturb. meas. This subject is also close to the top of my list of things to investigate... I've recently priced out a professional coupling network and to my surprise it weighed in with a hefty 10k (canadian) price tag. Does anyone have any reference designs for their own home grown solutions that they would be willing to share, or suggestions for manufacturers of surge coupling networks that may be more reasonably priced? I just have a hard time beleiveing that a passive surge coupling unit could be anywhere near ten thousand dollars complex... Thanks, Jeff Bailey Compliance Engineering Woodhead Software Electronics Phone: (519) 725 5136 ext. 363 Fax: (519) 725 1515 email: jbai...@mysst.com Web: www.mysst.com -Original Message- From: Konrad Stefanski [mailto:kstef...@poczta.onet.pl] Sent: September 19, 2003 3:20 AM To: emc-p...@ieee.org Subject: SURGE testing, disturb. meas. Hello list. What is the simplest way to couple Surge pulses (EN 61000-4-5) with telecomunication lines? I haven't got proffesional coupling network. And the second question, what is the simplest way to measure voltage of disturbances from telecomunication lines without proffesional ISN? Thank You for answers. Konrad Stefanski PCBC SA Warsaw kstef...@poczta.onet.pl
RE: antennas
Agreed -- keep the dipoles high enough so no one can walk into them... Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, August 29, 2003 2:49 PM To: emc-p...@majordomo.ieee.org Subject: Re: antennas I read in !emc-pstc that Mike Hopkins michael.hopk...@thermo.com wrote (in 49CD487E8BA9D31181190060081C6B8FA271C3@COMSERVER) about 'antennas' on Fri, 29 Aug 2003: I believe amateur radio products are exempt from the EN's. someone correct me if I'm wrong. Not exactly. Non-commercial constructions are not subject to the EMC Directive. Commercial products are so subject. Amateur constructors should certainly strive to make their constructions electrically safe! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Lightning Surge Characterization/Standards
For lightning in the power grid, see ANSI/IEEE C62.41.1 - 2002 Guide on the Surge Environment in Low-Voltage (1000V and Less) AC Power Circuits ANSI/IEEE C62.41.2 - 2002 Recommended Practice on Characterization of Surges in Low-Voltage (1000V and Less) AC Power Circuits ANSI/IEEE C62.45 -2002 Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage (1000V and Less) AC Power Circuits These deal with the AC power grid. I'm not aware of any equivilent documentation regarding the telecom line, other than early documents that pre-date the Bellcore 1089 stuff Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Stephen Phillips [mailto:step...@cisco.com] Sent: Tuesday, August 05, 2003 1:45 PM To: n...@world.std.com; t...@world.std.com; emc-p...@majordomo.ieee.org; a...@occamnetworks.com Subject: Re: Lightning Surge Characterization/Standards Anil, Remember, some of those tests you mention assume a Primary Protector is also in place. In the U.S. maybe you can assume this is true, but can you worldwide? Also, for some of those tests, the criteria for failing are fragmentation/fire, obviously the product would not continue to work then - but you may still hold a passing test report. In short, meeting those requirements assures a very limited degree of safety presented to the user and quality of the product, not a thoroughly robust lightning proof design. Best regards, Stephen At 12:37 PM 8/5/2003, Anil Allamaneni wrote: Greetings folks, We have products that meet all the Surge requirements of NEBS GR-1089, FCC-68 and EMC 4-5. But, the same products are continuously failing in the field due to real-world lightning strikes. I have spoken to four other manufacturers who make similiar interfaces (DSL) and they all have the same problem : they meet the standards, but fail in the real world. I have two questions for the esteemed people here : 1) Were these standards written based on somebody doing some field evaluations? Has IEEE/Bellcore done any research into what the waveforms really are for actual *real-world* lightning strikes? How do they do that? 2) Is somebody working on re-charaterization of lightning strikes throughout US (eg, the surges seem to be more lethal in TN as opposed to CA)? Would you have the contact details of Working Groups? Thanks a...@occamnetworks.com __ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com http://sitebuilder.yahoo.com/
RE: voltage dips
There is a new document in the works, IEC 61000-4-34, for dip interrupt testing of products drawing greater than 16A. It is currently a CD (Committee Draft). TC77A WG6, who is responsible for this document, meets in Spain in September, after which a CDV (Committee Draft for Vote) is possible. It is essentially the same as the 2nd revision of IEC 61000-4-11, now in the CDV stage. This revision will also be dealt with at the September meeting. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Paolo Peruzzi [mailto:paolo.peru...@esaote.com] Sent: Tuesday, July 22, 2003 6:45 AM To: emc-p...@majordomo.ieee.org Subject: voltage dips Hi all, Is there any basic standard concerning voltage dips and short interruptions immunity for equipment with input current larger than 16 amps per phase? And more: can a product standard prescribe such test for equipment with more than 16 amps per phase and still refer to 61000-4-11 as basic standard? Thanks, Paolo Peruzzi Esaote S.p.A. Research Product Development - Design Quality Control via di Caciolle, 15 I- 50127 Florence tel: +39 055 4229469 fax: +39 055 4223305 e-mail: paolo.peru...@esaote.com This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: FCC's inquiry for broadband over the powerlines (BPL)
All I know is that it seems to be a major problem in Europe, with lot's of HF spectrum uses seeing high levels of interference to services. Amateur Radio organizations world-wide are fighting it (including ARRL in the US). I heard a talk regarding this problem in Germany at the last IEEE EMC Symposium; may be more next month in Boston Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Garnier, David S (MED) [mailto:david.garn...@med.ge.com] Sent: Thursday, July 17, 2003 7:38 PM To: emc-p...@majordomo.ieee.org Subject: FCC's inquiry for broadband over the powerlines (BPL) Hello, I don't remember seeing any discussion on the listserve concerning this... As I understand this, this is a carrier current system, digital modulation format, frquencies ranging from 2 to 40 Mhz, amplitude limits of ~40 dB to 60 dB above Class A conducted emission limits. Anybody have any experiance or comments about this? For further explanation see: http://hraunfoss.fcc.gov/edocs_public/SilverStream/Pages/edocs.html Use the search term: broadband over power line thanks, dave garnier David Garnier e GE Medical Systems ___ David S. Garnier Senior Technician PET Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: ESD - not applicable ?
I understand the concerns and your reasoning, but if you define accessible as anything I CAN touch, then it would inlcude all surfaces, connectors and the like... There was considerable discussion in the Working Group regarding this issue, and as I recall, the concensus was that for compliance purposes, there can be accessible points and ports that are unlikely to be accessed by the operator during the normal use. These points, surfaces and ports can then be exempted from ESD testing. It's my feeling that the intent of the standard is to insure that the product is immune to human ESD events that are likely to occur during normal use -- in other words, test those points and ports the operator is likely to come in contact with during normal use; don't bother with those points NOT likely to be touched by the operator during normal use This is only for compliance purposes Maybe not good engineering practice, but that's where the second head comes in -- you'll probably have a more rugged and reliable product if you do test everything, but that's up to the manufacturer, not the compliance body. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Tuesday, June 24, 2003 11:16 AM To: Mike Hopkins; don_borow...@selinc.com; emc-p...@majordomo.ieee.org Subject: RE: ESD - not applicable ? Mike, I'm still not sold. I understand the specific exemptions for circuit cards, battery compartments and the like; but I can't follow the reasoning for exempting the outside of the product. How are you defining not accessible? It sounds as though you are gauging access by the need to touch a surface; not the ability/opportunity to touch a surface. For instance, I have two speakers attached to my PC. One of them is a slave. It doesn't have any volume controls on it. I never have to touch it once it is installed. Isn't it still accessible even though I don't have to touch it? If I were to mount this speaker up on a wall; it does reduce the probability that it will be touched while it's operating; but it doesn't eliminate it. So, I still consider it accessible. I understand that height is involved in the original question (device is installed higher than 2.5m from the floor). The problem here is: the product still can be touched; and I see no specific guidelines in any standard that says a product higher than x meters off of the floor is not accessible. To me, there are too many gray areas in this argument. My compliance head says that the outside surfaces that can be touched should be tested. AND I'M USUALLY ONE OF THE COWBOYS, LOOKING FOR EVERY LOOPHOLE I CAN FIND :-) I do agree with you on one point. If I were to exempt this product from ESD testing; I would cover my butt and label it as ESD sensitive. I think we both agree, from a quality standpoint, that ESD testing would be a good thing to do. One point that I'm sure of agreement/disagreement is indirect ESD testing. I think that, regardless of how you treat the surfaces; this product still needs indirect ESD testing. Do you agree with this? Best regards, Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | -Original Message- From: Mike Hopkins [SMTP:michael.hopk...@thermo.com] Sent: Tuesday, June 24, 2003 9:38 AM To: 'don_borow...@selinc.com'; emc-p...@majordomo.ieee.org Subject: RE: ESD - not applicable ? You always need to apply two heads --- the engineering head says,Good engineering practice says you should test for ESD, but the compliance head only needs to meet the requirement of the standard, which clearly exempts points and ports NOT accessible by an OPERATOR. Points and ports accessible for maintenace, installation and service need not be tested (compliance head). Points/ports that ARE accessible by the operator can be exempted by labeling -- i.e., ESD sensitive ports such as scope vertical amp inputs, RF antenna inputs, etc... Also specifically exempted from compliance to 61000-4-2 are inside battery compartments, which although accessed by the operator, are rarely accessed and when they do get into the battery compartment, the unit is inoperative Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation
RE: ESD - not applicable ?
You always need to apply two heads --- the engineering head says,Good engineering practice says you should test for ESD, but the compliance head only needs to meet the requirement of the standard, which clearly exempts points and ports NOT accessible by an OPERATOR. Points and ports accessible for maintenace, installation and service need not be tested (compliance head). Points/ports that ARE accessible by the operator can be exempted by labeling -- i.e., ESD sensitive ports such as scope vertical amp inputs, RF antenna inputs, etc... Also specifically exempted from compliance to 61000-4-2 are inside battery compartments, which although accessed by the operator, are rarely accessed and when they do get into the battery compartment, the unit is inoperative Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: don_borow...@selinc.com [mailto:don_borow...@selinc.com] Sent: Monday, June 23, 2003 5:58 PM To: emc-p...@majordomo.ieee.org Subject: RE: ESD - not applicable ? If installation is normal usage, then should all those bare boards installed in PCs should be tested for ESD resistance in their bare state? Or is the distinction between a product and a component that goes into a product (though some may argue that, for example, a modem board is a product)? But I certainly agree that a product never handled by end users should still be ESD resistant to successfully make it through the installation process (even if not required). Don Borowski Schweitzer Engineering Labs Pullman, WA USA Pettit, Ghery ghery.pettit@int el.comTo Sent by: richwo...@tycoint.com, owner-emc-pstc@ma emc-p...@majordomo.ieee.org jordomo.ieee.org cc Subject 06/23/03 01:40 PM RE: ESD - not applicable ? Please respond to Pettit, Ghery ghery.pettit@int el.com And installation is normal usage. Now, it would be interesting to know just what type of product we’re talking about. Ghery Pettit Intel Corporation From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Monday, June 23, 2003 1:05 PM To: emc-p...@majordomo.ieee.org Subject: RE: ESD - not applicable ? Clause 8.3.1 of EN 61000-4-2 says The static electricity discharges shall be applied only to such points and surfaces of the EUT which are acessible to personnel during normal usage. And it also says The application of discharges to any point of the equipment which is assessible only for maintenance purposes, excluding customer's maintenance, is not allowed unless different prescription is given in the dedicated product specification. So, unless the product or family spec says otherwise, no testing is required if a product is touched only during maintenance other than customer maintenance. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Monday, June 23, 2003 2:59 PM To: am...@westin-emission.no; emc-p...@majordomo.ieee.org Subject: RE: ESD - not applicable ? Amund, CISPR 24 (and EN 55024) provides reasons to not perform various tests, but ESD doesn’t have any of these “outs”. I think you are entirely correct in wanting the test done. Like you, I have seen this to be one of the more applicable immunity tests (along with surge) and we test to higher levels, too. Did the lab explain how the equipment would be installed, if not touched by human hands? Ghery S. Pettit Intel Corporation -Original Message- From: am...@westin-emission.no [mailto:am...@westin-emission.no]
RE: Automotive ESD
This is a good one and illustrates the charging effects!!! Let's say your inside the car driving. During that time, you build up some charge just from moving around inside and that charge is between you and the shell of the vehicle. As you exit, the charge you your person has nowhere to go, so it remains or even grows as you slide out, BUT the capacitance between you and the car is getting a lot smaller as you exit. If capacitance goes down and the charge remains, what happens to the voltage? It goes UP very quickly. As a result, the voltage between you and the shell of the car as you exit can get quite high -- high enough to break through the paint on the edge of the door where you're hanging on to it. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Locke, Darrell [mailto:dlo...@advanced-input.com] Sent: Monday, June 09, 2003 4:37 PM To: Mike Hopkins Cc: EMC-PSTC List Subject: RE: Automotive ESD Thanks to all who answered. The levels appear higher and this correlates to my own experience. I have noticed particularly in low humidity I really get some zaps when exiting my vehicle. Does anyone know why? An earlier response referred to being surrounded by metal results in greater capacitance. Thanks Darrell Locke Advanced Input Devices From: Mike Hopkins [mailto:michael.hopk...@thermo.com] Sent: Friday, June 06, 2003 2:51 PM To: Locke, Darrell Subject: RE: Automotive ESD There are several -- Ford, Chrysler, GM and others all have thier own -- then there is ISO, which is evolving towards the IEC 61000-4-2 model. Many require tests to 20kV and use discharge networks consisting of 300pf/5k, 330pf/2k and 150pf/2k among others. Some standards are: SAE J1113a, current in revision Chrysler PF 936B Ford ES-XW7T-1A278-AB EMC Requirements Overview ISO 7637-X And there are many more. Hope this is helpful. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Locke, Darrell [mailto:dlo...@advanced-input.com] Sent: Thursday, June 05, 2003 6:19 PM To: EMC-PSTC List Subject: Automotive ESD Group, Does anyone know the correct standard(s) for testing automotive ESD? Are these higher levels than Human Body ESD? Thanks Darrell Locke Advanced Input Devices
RE: Electrical Fast Transient (EFT) and the Real World
Actually, the EFT test pre-dates the IEEE reference. IEEE included a reference to IEC 801-4 in the earlier IEEE 587 document, which has now become ANSI/IEEE C62.41 (now reissued as a 2002 document as a Trilogy: C62.41, C62.42, and C62.45). In the 70's, EFT tests were being conducted in Europe using spark gap generators, or what were called showering arc generators. The EFT burst as we know it grew out of this. Unfortunately, neither the current IEC 61000-4-4 nor the older IEC 801-4-1988 contain any direct references for supporting material. In re-casting 61000-4-4 towards a revision, I looked for supporting documents but found only indirect information: a memo referring to work done by ABB in Sweden to define the transients; anecdotal information regarding the frequencies of real EFT to be in the MHz region, and a report from ABB Center in Mannheim of 1991 talking about the problems with EFT generators duplicating real field failures. I also have a New Work Item Proposal of 2000 from the Swedish National Committee. It contains data showing field measurements of EFT frequencies to be in the hundreds of MHz (vs. 2.5kHz and 5kHz in the current standard), and amplitudes of 1.5kV to 3.5kV. They propose burst frequencies from 400kHz to 25MHz and burst packets starting with low voltages at high repetition rates, ramping up to higher voltages at lower repetition rates. Some of this is now being dealt with in a proposed revision to IEC 61000-4-12, about to be circulated as a CDV, and will be reviewed by the SC77B Working Group 11 in the September meeting in Spain. Probably not useful info, but that's about it. Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation involvement From: Pat Lawler [mailto:pat.law...@verizon.net] Sent: Wednesday, June 04, 2003 10:55 AM To: EMC-PSTC Subject: Re: Electrical Fast Transient (EFT) and the Real World On Mon, 02 Jun 2003 16:51:47 -0400, Stephen Irving sirv...@lutron.com wrote: We are investigating the Electrical Fast Transient (EFT) test as detailed in IEC/EN 61000-4-4. I am looking for some experience/advise with this test. My understanding is that the IEC created this test to standardize fast line transient tests, such that a single repeatable test could be performed. As such, I am having a hard time finding information regarding the naturally occurring voltages and frequencies of these events. We are trying to expand the prescribed test into a real-world, worst case test. Does anyone have any experience or related documents that may help? Also, the test is prescribed to have a period of 300ms (15 line cycles at 50Hz). We are in the US, and are running the test at 60Hz (which does not work out to an even number of cycles - the beginning of the transient moves in time). Does anyone know if the test should be altered to provide a repeatable transient, or if there is a reason to leave it at 60Hz. I look forward to your comment - this is an interesting one! As always, thanks for your help. Best regards, Steve Irving It looks like the EFT test was copied from an older IEEE document circa 1980. Take a look at specification IEEE C62.41, Recommended Practice on Surge Voltages in Low-Voltage AC Power Circuits. Besides defining the waveshape of various transient waveforms (100kHz ringwave, Combination wave, 5n/50ns EFT, 10/1000us wave, 5kHz ringawave), it also has a section describing transients found in the United States. Pat Lawler pat.law...@verizon.net This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim
RE: ESD Problem
So is mine (hand up, that is) Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC ESD Simulation Systems One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 michael.hopk...@thermo.com One Thermo, committed to integrity, intensity, innovation and involvement From: Pommerenke, David [mailto:davi...@umr.edu] Sent: Tuesday, May 27, 2003 11:16 AM To: Luke Turnbull; emc-p...@ieee.org Subject: RE: ESD Problem My hand is up. David Pommerenke From: Luke Turnbull [mailto:luke.turnb...@trw.com] Sent: Tuesday, May 27, 2003 8:23 AM To: emc-p...@ieee.org Subject: ESD Problem Would the gentleman who is on the 61000-4-2 committee please put his hand up? Thanks, Luke Turnbull This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: question on IEEE standards activity addressing immunity stand ards
The first one to come to mind is ANSI C63.16 for ESD -- finished a document recently for ESD testing of products -- should be published soon Also, there is the IEEE SPD -- Surge Protective Devices -- group under the Power engineering society that just published ANSI/IEEE C62.41.1, C62.41.2 and C62.45 - replacements for the existing C62.41 and C62.45. Other working groups under the SPD are working on documents for protection in the telecom industry and power distribution systems Those are the only two I can think of this early in the morning Best Regards, Michael Hopkins Manager, EMC Products Control Technologies Division Thermo Electron 978 275 0800 ext. 334 michael.hopk...@thermo.com From: shbe...@rockwellcollins.com [mailto:shbe...@rockwellcollins.com] Sent: Wednesday, May 14, 2003 9:18 AM To: emc-p...@ieee.org Subject: question on IEEE standards activity addressing immunity standards Could anyone point me to a contact that may be aware of an IEEE standards activity addressing immunity standards? I assume concerned with whether or not commerical immunity standards are sufficiently stringent to address the increasing proliferation of electronic devices and their affect on the electromagnetic spectrum. Thanks in advance, Susan H. Beard This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Design of low cost ESD gun.
Since you can buy a compliant gun for a few thousand dollars (used, demos, etc), why would you want to spend at least that much in time and materials to get something close?? Mike Hopkins Thermo Electron michael.hopk...@thermo.com From: LEUNG YAT WAH DEREK [mailto:ywle...@vtc.edu.hk] Sent: Thursday, May 08, 2003 9:50 PM To: emc-p...@majordomo.ieee.org Subject: Design of low cost ESD gun. Can anyone provide some information about I want to make a low cost ESD gun for ESD test, the peak voltage about 4 or 8 k volt ( if it can induced + and - poloarity will be more better), the waveform just little similar to the specification, thanks. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: ESD gun verification
Because you're dealing with a relatively high frequency event, you really do need a good target and measurement system to verify that the waveform is in compliance That said, there are a number of ways to verify that the gun is working and is probably okay without going to any extremes. One way that is used by some is to make a simple resitive target (non-high frequency) that will allow you to look at the current waveform and get something that is repeateable. After the gun is calibrated and you are confident that the waveform is really correct - get waveforms --, you can then record the waveform you get with your homemade target. By comparing the waveform from the homemade target to what you got after calibration, you should be able to tell if there is a change in the gun -- it isn't likely there will be minor waveform variations that will cause the gun to go out of calibration -- more likely you'll see peaks that are not correct, no current, or peaks that are no longer controlled by adjusting the voltage level. By the way, we're trying to get a statement into the next revision of 61000-4-2 to make it clear that it is not the users responsibility to calibrate the waveform before each test -- any simple method that allows you to determine that the gun is still working properly AND a valid calibration sticker, will be good enough for VERIFICATION! Good luck. (Of course, you can always send it in for calibration -- you should do so yearly anyway.) Hope this helps, Best Regards, Michael Hopkins Thermo Electron michael.hopk...@thermo.com From: John Harrington [mailto:jharring...@f2labs.com] Sent: Thursday, May 01, 2003 2:46 PM To: 'emc-p...@majordomo.ieee.org' Subject: ESD gun verification Hello All Does any one have a quick and dirty (and hopefully cheap) way to verify the performance of an ESD gun. Please, no one suggest building the current sensing system described in the back of IEC 61000-4-2. I don't understand the drawings let alone have the workshop or materials to consider it. Although, I may pay someone to build it for me... I am desperate enough to consider buying something off the shelf (if I could find said shelf). All help appreciated John Harrington EMC Technical Manager F-Squared Laboratories This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: surge Z?
The surge generator specification is 2 ohms source impedance for testing in normal mode (line to line) and 12 ohms for testing in common mode (surges line to ground). Mike Hopkins Thermo Electron KeyTek From: drcuthbert [mailto:drcuthb...@micron.com] Sent: Wednesday, March 19, 2003 3:36 PM To: emc-p...@majordomo.ieee.org Subject: surge Z? Anyone know the source impedance used for EN 61000-4-5 Surge testing? Dave Cuthbert Micron Technology This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: RADIATED IMMUNITY REQUIREMENTS FOR EN61326
Sorry, but I must be missing something Transmitting antennas are designed to radiate power, and the field strength of any signal being radiated will be at it's highest close to the antenna in fact, depending on frequency and distance, one might even be in the near field effects Antennas may be made directional, which results in power being concentrated in one direction, but if you're talking broadcast antennas, they are generally omni-directional arrays that achieve gain by keeping fields concentrated at low angles so power radiated towards the sky is minimized. Such antennas would clearly produce their highest levels of radiation close to the antenna structure itself; however, directly above or below the antenna fields would be less. I cannot guess why the radiated levels for these frequencies would be lower than for other frequencies. The only thing I can think of is that maybe it isn't expected that one would be close enough to a broadcast antenna at these frequencies for it to be an issue (antennas are mounted atop very tall buildings and towers) -- on the other hand, a piece of lab equipment or control equipment in a process plant could certainly be very close to other sources or radiation from, say, 5W walkies used by security personnel -- how much of a field can you get a 150MHz a foot from a 5W transmitter?? Mike Hopkins Thermo KeyTek From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Monday, March 03, 2003 12:41 PM To: emc-p...@majordomo.ieee.org Subject: Re: RADIATED IMMUNITY REQUIREMENTS FOR EN61326 I read in !emc-pstc that Gordon,Ian ian.gor...@edwards.boc.com wrote (in E1BA0362B28ED211A1E80008C71EA3060206FB33@z- 160-100-30-252.est.ibm.com) about 'RADIATED IMMUNITY REQUIREMENTS FOR EN61326' on Mon, 3 Mar 2003: Furthermore, I have never been able to work out why there is a relaxation at these freqs. The wording from table 1 of EN61000-6-2 is 10V/m Except for the ITU broadcast frequency bands (given above) where the level shall be 3V/m. Can anyone provide the logic behind this clause? (I'm sure there is some!). The transmitter antennas are designed not to produce high field strengths even close to the antennas, because receivers would be severely overloaded and maybe damaged. I did some measurements on portable radios and, scaling up from what you get at the base of the first transistor with say 100 mV/m, you would get 1 to 2 V at 10 V/m, which could even damage the transistor. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: RADIATED IMMUNITY REQUIREMENTS FOR EN61326
I believe the other bands are television broadcast M. Hopkins Thermo KeyTek From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, March 03, 2003 11:03 AM To: Gordon,Ian; 'IEEE EMC-PSTC GROUP' Subject: Re: RADIATED IMMUNITY REQUIREMENTS FOR EN61326 Hazarding a guess. I am not near a spectrum usage chart, but clearly 87-108 is the FM broadcast band, and therefore no one else is transmitting at these frequencies, except at very low power. If the other bands listed are also restricted to broadcasters of a certain power, and you can calculate that the closest you might ever approach the source would limit you to a 3 V/m exposure, then the relaxation would make sense. Like I said though, just a guess. on 3/3/03 8:01 AM, Gordon,Ian at ian.gor...@edwards.boc.com wrote: Everybody Can you advise me as to whether the same reduction in field strength is available when applying the industrial immunity requirements of EN61326 as when applying the generic industrial immunity standard EN61000-6-2. EN61000-6-2 permits a reduction in field strength from 10 to 3 V/m over the following frequency ranges : 87 - 108 MHz 174 - 230 MHz 470 - 790 MHz Furthermore, I have never been able to work out why there is a relaxation at these freqs. The wording from table 1 of EN61000-6-2 is 10V/m Except for the ITU broadcast frequency bands (given above) where the level shall be 3V/m. Can anyone provide the logic behind this clause? (I'm sure there is some!). Thanks Ian Gordon _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Surge - injection point on screened cable
The 20m screened cable test is meant to test for the effects of a high surge current being carried on the shield between two, grounded EUT's. The intent of the standard is to test products in a configuration in which they would be installed, so unless the detectors are installed with 20m of cable between each one, I'd argue that your test lab is nuts In order to perform the test for screened cables, the item at each end of the shielded cable needs to be grounded so that you can insert a surge generator in such a way as to cause a surge current to flow on the surface of the cable. Don't know enough about your product to comment of the practicality fo such a test. Hope it's helpful... Mike Hopkins Thermo KeyTek -Original Message- From: am...@westin-emission.no [mailto:am...@westin-emission.no] Sent: Thursday, October 31, 2002 10:48 AM To: emc-p...@majordomo.ieee.org Subject: Surge - injection point on screened cable According to IEC/EN 61000-4-5, the surge pulse shall be injected onto a screened cable 20 meters from the DUT. We have a fire alarm system with 20 detectors connected on the same screened cable, 1.5 meters between each detector. We have been told from the local test lab that we have to add a 20m cable between each detector in order to surge test each detector. I'm sure our local cable distributor like that idea ... , but do we really have to do this ? Why is this 20 meters cable needed ? Is it to induce the surge pulse from the screen into the cable lines? The 20 detectors make a total cable distance of 30 meters and the screen is continuous. Is it possible to insert a pulse in the beginning of the cable and test all detectors simultaneous ? Regards Amund --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: EN61326:1997 Planning
These days, there are a number of combination testers on the market that will perform tests to both IEC 61000-4-5 and 61000-4-11. Thermo KeyTek has one for just under $10k that also does EFT and Mag fields for the same price Other manufacturers have similar units - prices depend on things like voltage (testing to as high as 6kV for surge), how the dip interrupt tests are done (external variac's and switches vs. internal tap switched transformers), software control, etc... I'll leave the CISPR 11 questions to someone more qualified than I am. Mike Hopkins -Original Message- From: Bill Flanigan [mailto:bflani...@ameritherm.com] Sent: Wednesday, October 30, 2002 10:27 AM To: emc-p...@majordomo.ieee.org Subject: EN61326:1997 Planning A few questions about compliance to EN 61326. Guidance requested from my emc-pstc colleagues What happened in Amendment 2; I have the standard to +A1 Immunity: EN 61000-4-5 [Imm'y Surge] what kind of equipment is needed to conduct this test? EN 61000-4-11[Imm'y Voltage dips] what kind of equipment is needed to conduct this test? Emissions: We manufacture equipment classified under EN55011 as ClassA Group2; we generate RF energy for industrial purposes, excluding communications. Section 7.2 says 'For equipment using ISM frequencies, see CISPR11.' *Does this mean _use_ EN55011:91 for emissions limits as I have been doing? EN 61326-1 doesn't mention anything about Group2 limits. *Is there now a distinction between ISM equipment and equipment using ISM frequencies? Not trying to split hairs here, but if it doesn't actually use ISM frequencies my equipment is calssified as ISM equipment, right? Wm Flanigan Standards Engineer Ameritherm Inc 1.800.456.4328 bflani...@ameritherm.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Australian Telecom Surge testing
The 10/700us waveform called out by IEC 61000-4-5 is essentially the same as the 9/720us waveform called for by FCC. Both require circuits based on old CCITT documents. There are some generators on the market that will meet both requirements (tolerances for each allow for the overlap). Older generators designed to meet only the CCITT or IEC specification may not also meet the 9/720us requirements of FCC. Both specify a 20uF energy storage capacitor for this waveform... Hope this helps... Mike Hopkins Thermo KeyTek -Original Message- From: John Cronin [mailto:croni...@hotmail.com] Sent: Tuesday, April 30, 2002 6:30 PM To: emc-p...@majordomo.ieee.org Subject: Australian Telecom Surge testing Hi group Can anyone tell me offhand whether the surge test requirement for Australia is to IEC 1000-4-5 which uses a network with a 1 uF source capacitor or is it similar to the FCC test which I believe uses a 20 uF capacitor. Best Regards John Cronin _ Join the world's largest e-mail service with MSN Hotmail. Click http://g.msn.com/1HM105301/46 Here --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: A very nice game
Agreed -- I've received this virus about 50 times in the last few days, but each time the system (local server) quarantines it.. Mike Hopkins Thermo KeyTek -Original Message- From: Robert Wilson [mailto:robert_wil...@tirsys.com] Sent: Wednesday, April 24, 2002 11:47 AM To: emc-p...@ieee.org Subject: RE: A very nice game In spite of the attachment having been removed by the system, it was pretty darned obvious what this must have been. It always amazes me that people are foolish (stupid?) enough to open attachments to obviously suspicious emails like this one, that are from people they don't know, and subjects that make no sense. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Bill Ellingford [mailto:bill.ellingf...@motion-media.com] Sent: April 24, 2002 4:37 AM To: 'jmw'; emc-p...@ieee.org Subject: RE: A very nice game Importance: High URGENT Please be aware that the above E-mail to the EMC group contained a virus. Fortunately our system removed it from the message. Bill Ellingford -Original Message- From: jmw [mailto:j...@jmwa.demon.co.uk] Sent: 24 April 2002 22:59 To: emc-p...@ieee.org Subject: A very nice game -- Virus Warning Message (on gemini2) setup.exe is removed from here because it contains a virus. - * --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: EMC test set-up for device with ethernet connection
David -- how are you coupling into the signal line?? The diagram shows the 0.5uF capacitor in series with a 40 ohm resistor -- are you using these values?? If I'm doing the math correctly, a 20mH coil has an impedance of about 12.5k ohms at 100kHz (2 x 3.14159 x 100kHz x 20mH), and about 370 ohms at 3kHz. If your signal line is balanced, there will be a choke in each line effectively doubling the impedance to the signal. Seems to me you won't get much signal through at any data rate over a few kHz. What am I missing?? The experiments we've done here show that the only way to get to 100kHz is to use resistors in place of the chokes and clamping protectors on the input side. (Chokes alone won't protect the input side from seeing a large surge voltage.) Additionally, most data lines won't tolerate the .5uF capacitor in series with the 40 ohms (and then the 2 ohms source impedance of the generator). That 42 ohms back into the generator places an effective load on the data line of 42 ohms to ground AFTER the 20mH chokes, forming a voltage divider of about 300:1. In our 100kHz version, we use arrestor coupling to minimize the capacitance hanging on the line. As a manufacturer, we make a coupler that incorporates both methods described above -- 20mH chokes and 0.5uF capacitor -- good to about 3kHz, plus the arrestor coupling with resistors -- good to about 100kHz. Best Regards, Mike Hopkins -Original Message- From: david_ster...@ademco.com [mailto:david_ster...@ademco.com] Sent: Friday, March 29, 2002 8:54 AM To: ari.honk...@nokia.com; david_ster...@ademco.com Cc: emc-p...@majordomo.ieee.org Subject: RE: EMC test set-up for device with ethernet connection Ari, Circuit diagram is EN61000-4-5: Figure 10. My coil was 20mH coil: www.wilcocorp.com P/N HFT-203 which has a DC resistance, R(L), of 2 ohms. The key is minimizing R(L). Ethernet incorporates internal threshold-detection and noise-rejection; low level signals are rejected both devices on the link. Twisted-Pair Ethernet is transformer-isolated at each end to eliminate DC; signal is inherently limited due to 100-ohm source impedence. David -Original Message- From: ari.honk...@nokia.com [mailto:ari.honk...@nokia.com] Sent: Thursday, March 28, 2002 2:26 AM To: david_ster...@ademco.com Cc: emc-p...@majordomo.ieee.org Subject: RE: EMC test set-up for device with ethernet connection David, if you have a decoupling circuit that keeps the surge away but passes ethernet, how about posting the details here? Lots of us would be most interested! Ari -Original Message- From: ext david_ster...@ademco.com [mailto:david_ster...@ademco.com] Sent: 27 March, 2002 22:20 To: richwo...@tycoint.com Cc: emc-p...@majordomo.ieee.org Subject: RE: EMC test set-up for device with ethernet connection Richard, We made our own decoupler with low-resistance 20mH coils. You really should have an active link during conditioning. Off-line surge will not detect a partitioned port; if there is no link, there can be no partition. A slow link is better than no link. David -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Wednesday, March 27, 2002 12:55 PM To: emc-p...@majordomo.ieee.org Subject: RE: EMC test set-up for device with ethernet connection You will not be able to transfer data when the decoupling network is added for the I/O surge test per EN61000-4-5. The data rate through the decoupler is very low. However, clause 7.7 allows you to use an alertnate test set-up. We do not use a decoupler to test our high speed network. We test the network before and after the surge application and disconnect the auxilary equipment with a relay for a short interval overlaping the surge application. We have recommended to the manufacturer of the surge generator that the IEC/CENELEC techincal committee include this test method in a revision of the standard. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: david_ster...@ademco.com [mailto:david_ster...@ademco.com] Sent: Wednesday, March 27, 2002 9:34 AM To: jan.mob...@philips.com Cc: emc-p...@majordomo.ieee.org Subject: RE: EMC test set-up for device with ethernet connection Here is one approach: Terminations: You need actual or simulated traffic (data packets) on the LAN. Terminate cables per IEEE802.x; the LAN link is a transmission line and must be correctly terminated (by LAN card or hub). Details depend on EUT functionality. Wiring configuration for emissions and immunity should be similar. If the EUT connects to a PC only via LAN, then the PC is AE; test the EUT as a stand-alone. If there are cables (USB, RS-232) to the PC or other AE, you must decide based on typical equipment proximity. Functionality during emissions test: I prefer constant signals for reproducibility. If EUT can simulate traffic
RE: Use of PCB Traces as Fuse and Voltage suppressor
Gas discharge tubes can be very complex devices and have a number of specifications. Normally the voltage spec that you see is the DC specification, in other words, the firing voltage if the voltage is slowly ramped up (2kV/second is on rate used); however, the impulse voltage -- the voltage at which the tube fires with a fast pulse (anywhere from 100V/us to 10kV/us) is normally much higher. One of the objectives in gas tube design is to get the DC and impulse voltages to be as consistent as possible, and as close together as possible (actually very difficult). Gas mixtures, doping, electrode geometry, etc. are all critical to the design. Some gas is sensitive to light, some work better in the light and for a while, some were doped with radioactivity to help control the firing point under different voltage impulse conditions. Hope this helps Nothing's ever simple. Best Regards, Mike Hopkins Thermo KeyTek. -Original Message- From: Robert Macy [mailto:m...@california.com] Sent: Wednesday, February 20, 2002 7:18 PM To: Chris Maxwell; bogda...@pacbell.net Cc: EMC-PSTC Internet Forum Subject: Re: Use of PCB Traces as Fuse and Voltage suppressor Our experience with gas discharge tubes was that they worked according to spec in the lab. fired perfectly around 400V like they're supposed to, but down inside of the PVC oil tank holding the 150KV isolation transformer they liked to fire at 600V+ Guess they needed photon energy to make the gas trigger or something. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Chris Maxwell chris.maxw...@nettest.com To: bogda...@pacbell.net bogda...@pacbell.net Cc: EMC-PSTC Internet Forum emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, February 20, 2002 2:15 PM Subject: RE: Use of PCB Traces as Fuse and Voltage suppressor Hi Bogdan, I'm sorry if you thought that my previous message was an endorsement for using necked down PCB traces as a fuse. I understand and share the sentiment that it is an unpredictable and probably not even cost effective solution. I was wondering why anyone would shape a PCB trace in such a way (two triangles pointing at each other with a thin trace between the points). A fuse is probably not the likely intention. A reasonable explanation may be a cut jumper. The triangles make the trace visible; while the thin trace provides an easy spot for the trace to be cut with an exacto knife which permanently removes the jumper.Another reason (suggested by a colleage) are alignment marks used by the PCB fab house to help align layers. Just to be sure... I'm not suggesting the above as design ideas. I'm just trying to figure out why anyone would do such a thing. One solution to the original problem that I haven't seen suggested is the good old air discharge tube, gas-discharge tube, gas tube ...whatever you want to call them. Of course, they aren't free (about $1 each). They are more predictable than open air terminals, they are UL/CSA recognized and they can handle some massive breakdown currents. They are available from Bourns and Sankosha USA... probably some other manufacturers as well. Chris -Original Message- From: bogdan matoga [SMTP:bogda...@pacbell.net] Sent: Wednesday, February 20, 2002 4:19 PM To: gab...@simex.ca; Chris Maxwell; emc-p...@mahordomo.ieee.org Subject: Use of PCB Traces as Fuse and Voltage suppressor Gabi: I believe that there is a basic rule which is not published anywhere: when you design something, then do it right. When transient suppressors are needed, then use the correct component, which will not depend on Paschen's Law and give predictable performance. Same for necked down fuses. When you want performance, then do it right. The above original suggestions are perfect for Mickey-Mouse-engineering. Bogdan. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit
RE: EN61000-6-2
I could be wrong -- need to go through the exercise and see if it makes sense Tell me if I'm missing something critical... 50ohm source, line, load and all connectors = no VSWR; adding any 50 ohm attenuator will not increase the VSWR. If any of the above is NOT 50 ohms, there will be reflections. So, since there seems to be some VSWR to start with, we need to assume one of the above is not 50 ohms. If the load is a high impedance, you are correct and adding an attenuator will make the VSWR look better from the source end (keeping in mind, the VSWR between the attenuator and load doesn't change). The attenuator in parallel with the high impedance load will bring the total impedance closer to 50 ohms -- not sure, but it may be that the larger the attenuator the better the match will become?? Have to think on that If the load is a low impedance, say 10 ohms, adding the attenuator will add impedance as far as the source is concerned, so again, the VSWR will appear to improve, and again, the VSWR between the attenuator and load remains high. Depending on the attenuator design, it also seems a bigger attenuator (more dB) will improve the VSWR more. So if I stick with that line of thinking -- adding an attenuator when the load is mis-matched will always reduce the VSWR at the source but never between the line and the load! (Obvious question: does the VSWR at the load matter?? Seems there would be some losses, and in some cases it could mean a lot, but that's for another day.) Mike Hopkins -Original Message- From: Jacob Schanker [mailto:schan...@frontiernet.net] Sent: Wednesday, February 20, 2002 4:01 PM To: Mike Hopkins; 'Colgan, Chris'; EMC Forum Subject: Re: EN61000-6-2 Mike: My experience tells me that an attenuator designed for the same impedance as the transmission line, will **always** improve the VSWR at the source, irrespective of how bad or good the load VSWR is. (It is most helpful to think in terms of reflection coefficients rather than VSWR directly, to appreciate this.) Your comment implies otherwise, and I wonder if you could expand on what you've said - perhaps an example of where it doesn't help (not a given)? Regards, Jacob Z. Schanker, P.E. 65 Crandon Way Rochester, NY 14618 Phone: 585 442 3909 Fax: 585 442 2182 j.schan...@ieee.org - Original Message - From: Mike Hopkins mhopk...@thermokeytek.com To: 'Colgan, Chris' chris.col...@tagmclaren.com; EMC Forum emc-p...@ieee.org Sent: Wednesday, February 20, 2002 1:48 PM Subject: RE: EN61000-6-2 | | Seems an attenuator COULD improve matching and VSWR if it then became a | significant part of the load impedance; it isn't a given. On the other | hand, adding the attenuator should NOT cause the VSWR to become very high | unless it is not a 50 ohm attenuator.. | | Mike Hopkins | | -Original Message- | From: Colgan, Chris [mailto:chris.col...@tagmclaren.com] | Sent: Wednesday, February 20, 2002 4:26 AM | To: EMC Forum | Subject: RE: EN61000-6-2 | | | | In my experience attenuators improve impedance matching and hence VSWR. | There must be something wrong with your set up. | | Regards | | Chris Colgan | Compliance Engineer | TAG McLaren Audio Ltd | The Summit, Latham Road | Huntingdon, Cambs, PE29 6ZU | *Tel: +44 (0)1480 415 627 | *Fax: +44 (0)1480 52159 | * Mailto:chris.col...@tagmclaren.com | * http://www.tagmclaren.com | | | -Original Message- | From: Sam Wismer [SMTP:swis...@bellsouth.net] | Sent: 19 February 2002 16:52 | To: EMC Forum | Subject: EN61000-6-2 | | Hi Group, | | EN 61000-6-2 calls for severity level 3, or 10Vrms for conducted | disturbances. This equates to 37dBm which is 7dB higher than the upper | limit my receiver will handle (during calibration of the CDN). I've tried | to use an attenuator and compensate for it in my readings, but this | creates a high VSWR. Any ideas how to extend the dynamic range of my | receiver without causing high VSWR? | | | | | | Kind Regards, | | | | | | Sam Wismer | | Engineering Manager | | ACS, Inc. | | | | Phone: (770) 831-8048 | | Fax: (770) 831-8598 | | | | Web: www.acstestlab.com | | | | | | ** |Please visit us at www.tagmclaren.com | ** | | The contents of this E-mail are confidential and for the exclusive | use of the intended recipient. If you receive this E-mail in error, | please delete it from your system immediately and notify us either | by E-mail, telephone or fax. You should not copy, forward or | otherwise disclose the content of the E-mail. | | TAG McLaren Audio Ltd | The Summit, 11 Latham Road | Huntingdon, Cambs, PE29 6ZU | Telephone : 01480 415600 (+44 1480 415600) | Facsimile : 01480 52159 (+44 1480 52159) | | ** |Please visit us at www.tagmclaren.com
RE: EN61000-6-2
Seems an attenuator COULD improve matching and VSWR if it then became a significant part of the load impedance; it isn't a given. On the other hand, adding the attenuator should NOT cause the VSWR to become very high unless it is not a 50 ohm attenuator.. Mike Hopkins -Original Message- From: Colgan, Chris [mailto:chris.col...@tagmclaren.com] Sent: Wednesday, February 20, 2002 4:26 AM To: EMC Forum Subject: RE: EN61000-6-2 In my experience attenuators improve impedance matching and hence VSWR. There must be something wrong with your set up. Regards Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclaren.com * http://www.tagmclaren.com -Original Message- From: Sam Wismer [SMTP:swis...@bellsouth.net] Sent: 19 February 2002 16:52 To: EMC Forum Subject: EN61000-6-2 Hi Group, EN 61000-6-2 calls for severity level 3, or 10Vrms for conducted disturbances. This equates to 37dBm which is 7dB higher than the upper limit my receiver will handle (during calibration of the CDN). I've tried to use an attenuator and compensate for it in my readings, but this creates a high VSWR. Any ideas how to extend the dynamic range of my receiver without causing high VSWR? Kind Regards, Sam Wismer Engineering Manager ACS, Inc. Phone: (770) 831-8048 Fax: (770) 831-8598 Web: www.acstestlab.com ** Please visit us at www.tagmclaren.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error, please delete it from your system immediately and notify us either by E-mail, telephone or fax. You should not copy, forward or otherwise disclose the content of the E-mail. TAG McLaren Audio Ltd The Summit, 11 Latham Road Huntingdon, Cambs, PE29 6ZU Telephone : 01480 415600 (+44 1480 415600) Facsimile : 01480 52159 (+44 1480 52159) ** Please visit us at www.tagmclaren.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Company close down due to EMC phenomena
Although there is no AM broadcast below 530kHz, there are still many services using the frequencies between 200kHz and 530kHz, the most important of which is the aviation industry. Called NDB's, these low frequency signals are still used for navigation globally and instrument approaches in airports world-wide. From a vantage point several thousand feet above the local power lines, a 25ms burst once/hour would be no big deal, but if there are lots of 25ms bursts/hour in a given area, this could be a problem! Mike Hopkins Thermo KeyTek (pilot of small airplane who does not want the ADF needle going around in circles -- especially when in use by pilot trying to figure out which way's home) -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 16, 2002 4:53 PM To: am...@westin-emission.no; emc-p...@majordomo.ieee.org Subject: Re: Company close down due to EMC phenomena A technical response from an American. I sympathize with the viewpoint that the duty cycle is very low and the on-time is very low and the potential for mischief is near nil. I would add a further argument. 55022 CE limits protect AM radio reception. In the USA there is no AM broadcast below 530 kHz. In the EU there is some LW broadcasting from I believe 150 - 300 kHz, and then MW picks up again at 530 kHz. So the potential for rfi is limited. That officials would even consider banning such a product is an argument against anyone having such power. -- From: am...@westin-emission.no To: emc-p...@majordomo.ieee.org Subject: Company close down due to EMC phenomena Date: Wed, Jan 16, 2002, 2:17 PM Well, this might be the reality in a case I have been introduced to lately. Case: A company are manufacturing PowerLine Communication products. They communicate via the power lines and a typical link is between a consumer residence and the nearest power station. The products can of course also communicate inside the consumers residence. The communication protocol is called CEBus http://www.cebus.org/which and make use of the frequency band 100kHz-400kHz and the amplitude is approximate 2-5V. A typical length of a transmission is 25ms and occurs approximate one time pr hour. First of all, AFAIK PowerLine Communication and PowerLine Transmission (broadband 1.6MHz-30MHz) are now coming will full force in EU and CENELEC/ETSI are working together regulate this type of transmission path and also coming up with standards. The problem for the manufacturer is the conducted emission requirements in EU. According to the EN55022B levels the maximum quasi-peak emission is 66dBuV@150kHz, and a typical PLC (under transmission) which has been measured, showed the value of 120dBuV (peak). With no transmission it had a margin of 10dB (quasi-peak) and 30dB (average). The radiated emission had a margin of 10dB. Well, conducted emission is the problem when transmitting. But, as I said, the transmission occurs only 25ms/hour. The national authority will not allowed this product to be placed into the marked because it do not fulfil the EN55022B limits (100kHz-400kHz) under transmission mode. No way. Other national authorities have other approaches on this case, they say as long as you do not disturb other equipment, install it. If you do disturb, we will come and remove it. They also say install it even if it does not fulfil EN550022B, but we will remove it if it disturb others. Two completely different approaches as you see. Questions: 1. Is it possible to have different approaches within EU ? 2. Since PLC/PLT is quite new technology and since we do not have any EU product standard (no standard for whose who are using 100kHz-400kHz band), I like the approach as long as you do not disturb other equipment, install it. If you do disturb, we will come and remove it. What is your opinion about this? 3. The transmission occurs very seldom. 25ms/hour, that is 7e-6 and approximate 0,001% transmission rate. Can this seldom transmission rate be an argument to not test the PLC product under continuous transmission ? I would say yes, but which rate is acceptable / reasonable ? So, why should the company close down ? Because if the national authority gets what they want, there will be one sale. Logical, but is it a correct prohibition the authority call? Best regards Amund Westin, Oslo/Norway --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute
RE: EN50091-2:1995
Oops. Meant to say the 801 series is obsolete and replaced by the IEC 61000-4-X series, which is true.. Mike H. -Original Message- From: Mike Hopkins [mailto:mhopk...@thermokeytek.com] Sent: Friday, January 11, 2002 1:42 PM To: 'Sam Wismer'; EMC Forum Subject: RE: EN50091-2:1995 The entire 801 Series is obsolete and replaced by the EN61000-4-X series; 61000-4-2, 61000-4-3, 61000-4-4 and 61000-4-5. It sounds like the product standard you have is out of date and needs to be revised, if it hasn't been already, to call out the new standards. Today, virtually all product standards call for testing to 61000-4-2 (ESD), 61000-4-3 (RF Radiated), 61000-4-4 (EFT), 61000-4-5 (Surge), 61000-4-6 (RF Conducted) and 61000-4-11 (Dip and Interrupts). Additionally, virtually all product standards require emissions testing as well. It is possible a revision of EN50091-2:1995 would not call for surge testing, but more than likely, it will. I would think if surge immunity were to be required for any set of products, UPS's would be at the top of the list. I'd recommend it whether you're required to do surge testing or not. (Be careful, I sell surge testers, so you better get other opinions!) Good Luck. Mike Hopkins Thermo KeyTek -Original Message- From: Sam Wismer [mailto:swis...@bellsouth.net] Sent: Friday, January 11, 2002 10:06 AM To: EMC Forum Subject: EN50091-2:1995 Hi all, I am reviewing EN50091-2:1995 to determine the immunity requirements for UPS systems. According to the harmonized list, this is the correct version of the standard under the EMCD. It calls for radiated emissions, IEC 801-2, -3 and -4. It then says 801-5 is under consideration. Our customer is requesting 801-5, but based on how I read the standard, it is not required at this time. Could that be true? Kind Regards, Sam Wismer Engineering Manager ACS, Inc. Phone: (770) 831-8048 Fax: (770) 831-8598 Web: www.acstestlab.com
RE: EN50091-2:1995
The entire 801 Series is obsolete and replaced by the EN61000-4-X series; 61000-4-2, 61000-4-3, 61000-4-4 and 61000-4-5. It sounds like the product standard you have is out of date and needs to be revised, if it hasn't been already, to call out the new standards. Today, virtually all product standards call for testing to 61000-4-2 (ESD), 61000-4-3 (RF Radiated), 61000-4-4 (EFT), 61000-4-5 (Surge), 61000-4-6 (RF Conducted) and 61000-4-11 (Dip and Interrupts). Additionally, virtually all product standards require emissions testing as well. It is possible a revision of EN50091-2:1995 would not call for surge testing, but more than likely, it will. I would think if surge immunity were to be required for any set of products, UPS's would be at the top of the list. I'd recommend it whether you're required to do surge testing or not. (Be careful, I sell surge testers, so you better get other opinions!) Good Luck. Mike Hopkins Thermo KeyTek -Original Message- From: Sam Wismer [mailto:swis...@bellsouth.net] Sent: Friday, January 11, 2002 10:06 AM To: EMC Forum Subject: EN50091-2:1995 Hi all, I am reviewing EN50091-2:1995 to determine the immunity requirements for UPS systems. According to the harmonized list, this is the correct version of the standard under the EMCD. It calls for radiated emissions, IEC 801-2, -3 and -4. It then says 801-5 is under consideration. Our customer is requesting 801-5, but based on how I read the standard, it is not required at this time. Could that be true? Kind Regards, Sam Wismer Engineering Manager ACS, Inc. Phone: (770) 831-8048 Fax: (770) 831-8598 Web: www.acstestlab.com
RE: Something a little different - Car Radio question
1. Does the radio work reasonable well on FM? If so, then the antenna is probably connected correctly. 2. Car radios used to have a variable capacitor that needs to be adjusted to match the antenna being used. (Haven't been that business for several years, so I don't know what they do now.) Sometimes this is accessible through the tape player door on the front, behind some removable piece on the front, or from the back. If not adjusted, AM reception can be VERY poor. Some novice installer may not know this. This should be in the installations/owners manual. 3. Some car radios have an internal antenna switch (electronic) that switches the antenna lead from the FM RF input stage, to the AM mixer (often no RF stage). Could be faulty. 4. If the problem is noise blanking all AM stations, could be faulty plug wiring in the vehicle, but this is very unlikely since the previous radio worked well. 5. Just what are the symptoms -- no noise, white noise and no signal, loud popping noise, . Good luck, Mike Hopkins Thermo KeyTek -Original Message- From: Cortland Richmond [mailto:cortland.richm...@alcatel.com] Sent: Thursday, January 03, 2002 6:32 PM To: Charles Grasso Cc: emc-p...@majordomo.ieee.org Subject: Re: Something a little different - Car Radio question Some cars do this? Nonsense! As you of course know. 1. It may be that your windshield antenna will not work with the particular model radio you got, which would only mean drilling a small hole and installing a whip. You should be able to find this out by calling the manufacturer and asking. 2. Less charitably, the folks who put your radio in may have broken your windshield antenna (necessitating a replacement windshield, which they will NOT want to pay for) and are either unable to figure it out, unwilling to fix it, or are trying to force you into having a different, and more expensive, radio installed. That last is called bait and switch and borders on the criminal in most states. Some obvious reactions come to mind. Calling the national or regional Best Buys office. Calling your state's consumer protection office (they may have handled pervious complaints from this store.) Suing them repair the damage to your car. Others are probably forthcoming, here! Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Charles Grasso wrote: Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the world's largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http
RE: EMC-related safety issues
As already stated, the incident of the DC-10 has for years been used as an example of personal electronics (laptops) interfering with avionics. The only version I've ever heard (and the only one that makes sense) had to do with interference to an ILS receiver operating somewhere between 108MHz and 118MHz. I for one, don't believe in laptop computers interfering with a compass -- UNLESS -- the people reporting the story (and writing the guide?) used a compass as a way to relate to the general population that a laptop caused interference with an instrument that kept the airplane headed in the right direction -- probably assuming that most people would not be able to relate to an ILS or NAV receiver, but everyone knows what a compass is. I remember the magazine article, which also reported on an electronically controlled wheelchair going out of control when an EMT keyed a mobile two-way radio in a nearby ambulance. (I might add, I've since heard several variations on that story as well -- wheelchair went over a cliff, wheelchair went around in circles, wheelchair dumped patient and took of by itself; radio was a walkie-talkie, radio was CB, etc You get the idea.) There was also a video being circulated of a Connie Chung news broadcast relating similar horror stories of the effects of EMC. We used to have a copy here, but I haven't seen it in years -- probably dumped when we moved. My 2 cents worth.. Mike Hopkins Thermo KeyTek -Original Message- From: Cortland Richmond [mailto:cortland.richm...@alcatel.com] Sent: Wednesday, January 02, 2002 2:56 PM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues It is perhaps less than useful to depend on a third or fourth party report of an incident to justify preventive measures. The mention in the Guide, of an aircraft compass being changed ten degrees by a laptop computer, is an example of a report which needs to be more completely reported. I was disappointed not to see it followed up in the Annex. I was curious about this because I was an avionics technician for 14 years and have been in EMI since 1983 -- over 13 years of that in the computer industry -- and I've never seen that effect caused by a device such as a laptop computer, only from large magnetic fields (such as DC motors). It struck me as unlikely that an aircraft compass could be affected by a laptop. Other systems, yes, the compass, no. The citation for the referenced incident was Compliance Engineering (CE magazine), the European edition, for November/December 1996. It probably also appeared in the US edition. I contacted CE Magazine, who are looking for a copy of that issue, so I may get a copy of the article. I expect I'll end up at the Department of Transportation's Web site, once I know the exact date of the event. However, one of the list members might have in his library a copy of that issue from 1996, and can report what the article actually says. That would be a step forward. I've personally been involved with similar incidents of people using computers made by my (at the time) employers where there had been a request to turn off a laptop due to interference with aircraft navigational or communications systems. In one case, a specific frequency was reported. Yet when the computer was checked, I could find no trace of an emission anywhere near the frequency supposedly affected. Cheers, Cortland Richmond (my opinion's, not my employers') cherryclo...@aol.com wrote: I won't get into whether you were intending to impugn my truthfulness, and shall assume you just used an unfortunate turn of phrase. I had already said I was not aware of the previous communications on this issue, so I could not have been aware that you were restricting the discussion to the kinds of emissions controlled by CISPR 22 and Title 47, part 15B of the US Code of Federal Regulations. I thought the concern was for spurious emissions in the wider sense of electromagnetic engineering. I don't believe that CISPR 22 (or any other European EMC standards) even mentions the term 'spurious emissions' much less defines it. Also, CISPR 22 does not control all the possible emissions from equipment that comes under its scope, for example it does not limit emissions above 1GHz as yet, or below 150kHz. Anyway, CIPSR22 and Title 47, part 15B of the US Code of Federal Regulations only covers certain kinds of equipment, and other EMC standards may allow higher levels of 'spurious' emissions. To take just one example: EN 50199:1996 covers the emissions from welding equipment and allows such high levels of emissions that it requires manufacturers of such machinery to warn users that even though the welding equipment meets the limits of the standard it could still cause interference to computers, safety critical equipment, pacemakers, hearing aids, etc. Other examples of standards which permit much high
RE: surges on 24VAC
Most Surge testers having ac mains couplers will also work with DC power (some require minor options to work), so actually doing the test is pretty easy Question as I read it was if it is in fact reasonable Mike Hopkins Thermo KeyTek -Original Message- From: KC CHAN [PDD] [mailto:kcc...@hkpc.org] Sent: Monday, December 17, 2001 8:49 PM To: jb...@bb-elec.com; emc-p...@majordomo.ieee.org Subject: Re: surges on 24VAC I am thinking if it is possible to connect the source input to the surge tester to a DC source, instead of the AC source, then you can apply the surge tests to the DC input of your product. Jennifer Banh jb...@bb-elec.com 12/18/01 03:43am Hello everyone, I am currently trying to test a product of ours that falls under 50082-1 generic standard for light industrial equipment. Our problem is that we have a 24VAC power input port. The generic standard calls out for EN 61000-4-5 on AC power input ports. After looking at EN 61000-4-5 it seems that it is intended for AC mains voltages, but I couldn't find anything that says a 24VAC input is exempt from this test. I am looking for outside opinions on whether this test is truly applicable. Thanks, Jennifer Banh BTW, we already tried just testing to the spec, and failed. Any suggestions on how to protect against this test would also be appreciated. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: surges on 24VAC
The surge test in 61000-4-5 is for testing for the effects of a lightning remnants getting into the mains or an I-O/Telecom line. Some product committees require surge tests to any power port, regardless of the source of that power, but it seems to me that unless the 24V power is from a distributed DC system coming from outside a structure where a lightning remnant could get in, lightning testing doesn't make much sense. We it WOULD make sense is to unit that converts the AC into 24V!. It seems there are such things as distributed DC systems (i.e. the telephone system in the US is a 48V DC system bring DC into homes and buildings from wires strung on telephone poles) and for these systems, lightning testing might make sense -- hence no provision in the standard that makes DC systems exempt from testing. Hope this is helpful... Mike Hopkins Thermo KeyTek -Original Message- From: Jennifer Banh [mailto:jb...@bb-elec.com] Sent: Monday, December 17, 2001 2:44 PM To: emc-p...@majordomo.ieee.org Subject: surges on 24VAC Hello everyone, I am currently trying to test a product of ours that falls under 50082-1 generic standard for light industrial equipment. Our problem is that we have a 24VAC power input port. The generic standard calls out for EN 61000-4-5 on AC power input ports. After looking at EN 61000-4-5 it seems that it is intended for AC mains voltages, but I couldn't find anything that says a 24VAC input is exempt from this test. I am looking for outside opinions on whether this test is truly applicable. Thanks, Jennifer Banh BTW, we already tried just testing to the spec, and failed. Any suggestions on how to protect against this test would also be appreciated. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 2 Phases in North America
This could be interesting::; if 50/60 is the 0th, then 100/120 would be the 1st ?? Makes sense to me!! No harmonics of the fundamental frequency would be the 0th; and 1st harmonic would be at twice the fundamental frequency. (I know this is not the convention, but it seems logical: first harmonic is fundamental plus the fundamental (once); second is the fundamental plus the fundamental x 2, etc. ). I like it! Mike Hopkins Thermo KeyTek -Original Message- From: bogdan matoga [mailto:bogda...@pacbell.net] Sent: Sunday, December 16, 2001 8:03 PM To: Cortland Richmond Cc: Jayasinghe, Ryan; Robert Johnson; 'Barry Esmore'; 'EMC-PSTC Forum' Subject: Re: 2 Phases in North America Cortland: I always thought that 50 Hz or respectively 60 Hz was the 0-th harmonic! Was I mistaken? (I would not be surprised!) (: -) !! Bogdan. Cortland Richmond wrote: This is rather similar to asking what the first harmonic of the power line frequency is. (grin!) Cortland Jayasinghe, Ryan wrote: 180° out of phase? --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Methods Equipment; Surge Dips
To answer the below -- KT has had the equipment for about 10 years. For rental -- call Transient Specialists at 866-364-7368. For robustness -- need to know the load. Large in-rush currents are generally no problem. I agree about the Pacific Power units -- we evaluated them here some years ago -- they were one of the few AC sources that weren't upset with transients on the output stage coming back from an EUT. Mike Hopkins -Original Message- From: Ehler, Kyle [mailto:keh...@lsil.com] Sent: Tuesday, November 20, 2001 3:57 PM To: 'Mike Hopkins'; Ehler, Kyle; 'wmf...@aol.com'; emc-p...@ieee.org Subject: RE: Methods Equipment; Surge Dips True, but did KT have this equipment 4yrs ago? Does anyone you know of rent this equipment? We also have a Schaffner tap switcher, but it eats itself under heavy loads. Is the KT stuff more robust under heavy startup loads? The Pacific Power equipment I use has never broke down. Worth the weight just for that... kyle -Original Message- From: Mike Hopkins [mailto:mhopk...@thermokeytek.com] Sent: Tuesday, November 20, 2001 2:47 PM To: 'Ehler, Kyle'; 'wmf...@aol.com'; emc-p...@ieee.org Subject: RE: Methods Equipment; Surge Dips Seems to me this is the hard way to do it. KeyTek has a product that is a tap switcher for the required levels and will pass the in-rush currents required. It's a much smaller package. Also, other manufacturers have systems that are basically software controlled switches -- bring in the AC levels you require via a variac or some other transformer and simply switch between them Mike Hopkins -Original Message- From: Ehler, Kyle [mailto:keh...@lsil.com] Sent: Tuesday, November 20, 2001 1:19 PM To: 'wmf...@aol.com'; emc-p...@ieee.org Subject: RE: Methods Equipment; Surge Dips Hi William, I dont know about renting equipment for the tests. You can probably find it. For the -4-11 (dip/dropout) test; Depending on your load, your site wiring has to be up to snuff. The power sources for doing the dip and dropout test are hefty stuff. My lab uses a three-phase powered source to deliver a max of 16A into a single phase capacitive (SMPS) load. I have a Pacific Power 140 TMX and an AMX 390. The 140 does flicker/harmonics and can do dip/dropout within its output limits (about 10A inrush). Any loads beyond a 10A inrush gets dip/dropout tested by the 390. The 140 is totally pc controlled but can be programmed through the front panel. It is a handy doer. The 390 is the heavy (up to 20A inrush) and I program it through the front panel for the desired dips and dropouts. There are some models that are computer attached (RS232 or IEEE488) and you execute software programmed routines for the test. Mitigation? Most EUT's can easily withstand half and single cycle drop, many can take a little more (up to 5 cycles) before going seriously anemic. Same is true for sags if the mains are wide range input. If you fail, you reselect the product's power supply, or beef up the input bulk capacitance (assuming SMPS type) or adjust the monitoring circuitry (i.e. remote sense, power good signal) for slower response and/or higher threshold. For the -4-5 (surge) test; We use a schaffner NSG 650 attached to a pc running the schaffner surge software. The surges are delivered to the EUT through a CDN 110 coupler. The cross coupling changes are manual jumpers. We also have a Haefely Psurge 4010 and 32.1 coupling filter for heavy loads. The cross coupling changes are automatic. The EUT supply cord length has to be no longer than .8M to the surge generator. make a custom cable This test series can damage your EUT, so you might want to do this test last. Mitigation of failures takes on a myriad of possibilities. Wiring length, TVSS absorber capacity, etc. It is hard to say without knowing more about your product. Do you also need to do the -4-4 (EFT) test? All this test gear is large and heavy, particularly the power sources and stepping xformers. Perhaps someone else can elucidate on exceptions to Class A rules? I gotta go, Happy Hunting, Kyle Ehler KCØIQE mailto:kyle.eh...@lsil.com mailto:kyle.eh...@lsil.com Assistant Design Engineer LSI Logic Storage Systems Div. 3718 N. Rock Road U.S.A. Wichita, Kansas 67226 Ph. 316 636 8657 Fax 316 636 8321 -Original Message- From: wmf...@aol.com [ mailto:wmf...@aol.com mailto:wmf...@aol.com ] Sent: Monday, November 19, 2001 10:29 AM To: emc-p...@ieee.org Subject: Methods Equipment; Surge Dips Esteemed listmembers, In gearing-up for testing under the auspices of EN61326:97, I'm trying to understand two immunity tests: EN61000-4-5 (surge immy) and -4-11 (dips immy). Is there test equipment one can rent to conduct these tests? What sort of mitigation steps are typical. Is anyone aware of any exceptions for this testing under ClassA rules? Thanks in advance... Wm Flanigan Standards Engineer Ameritherm Inc
RE: Methods Equipment; Surge Dips
Seems to me this is the hard way to do it. KeyTek has a product that is a tap switcher for the required levels and will pass the in-rush currents required. It's a much smaller package. Also, other manufacturers have systems that are basically software controlled switches -- bring in the AC levels you require via a variac or some other transformer and simply switch between them Mike Hopkins -Original Message- From: Ehler, Kyle [mailto:keh...@lsil.com] Sent: Tuesday, November 20, 2001 1:19 PM To: 'wmf...@aol.com'; emc-p...@ieee.org Subject: RE: Methods Equipment; Surge Dips Hi William, I dont know about renting equipment for the tests. You can probably find it. For the -4-11 (dip/dropout) test; Depending on your load, your site wiring has to be up to snuff. The power sources for doing the dip and dropout test are hefty stuff. My lab uses a three-phase powered source to deliver a max of 16A into a single phase capacitive (SMPS) load. I have a Pacific Power 140 TMX and an AMX 390. The 140 does flicker/harmonics and can do dip/dropout within its output limits (about 10A inrush). Any loads beyond a 10A inrush gets dip/dropout tested by the 390. The 140 is totally pc controlled but can be programmed through the front panel. It is a handy doer. The 390 is the heavy (up to 20A inrush) and I program it through the front panel for the desired dips and dropouts. There are some models that are computer attached (RS232 or IEEE488) and you execute software programmed routines for the test. Mitigation? Most EUT's can easily withstand half and single cycle drop, many can take a little more (up to 5 cycles) before going seriously anemic. Same is true for sags if the mains are wide range input. If you fail, you reselect the product's power supply, or beef up the input bulk capacitance (assuming SMPS type) or adjust the monitoring circuitry (i.e. remote sense, power good signal) for slower response and/or higher threshold. For the -4-5 (surge) test; We use a schaffner NSG 650 attached to a pc running the schaffner surge software. The surges are delivered to the EUT through a CDN 110 coupler. The cross coupling changes are manual jumpers. We also have a Haefely Psurge 4010 and 32.1 coupling filter for heavy loads. The cross coupling changes are automatic. The EUT supply cord length has to be no longer than .8M to the surge generator. make a custom cable This test series can damage your EUT, so you might want to do this test last. Mitigation of failures takes on a myriad of possibilities. Wiring length, TVSS absorber capacity, etc. It is hard to say without knowing more about your product. Do you also need to do the -4-4 (EFT) test? All this test gear is large and heavy, particularly the power sources and stepping xformers. Perhaps someone else can elucidate on exceptions to Class A rules? I gotta go, Happy Hunting, Kyle Ehler KCØIQE mailto:kyle.eh...@lsil.com mailto:kyle.eh...@lsil.com Assistant Design Engineer LSI Logic Storage Systems Div. 3718 N. Rock Road U.S.A. Wichita, Kansas 67226 Ph. 316 636 8657 Fax 316 636 8321 -Original Message- From: wmf...@aol.com [ mailto:wmf...@aol.com mailto:wmf...@aol.com ] Sent: Monday, November 19, 2001 10:29 AM To: emc-p...@ieee.org Subject: Methods Equipment; Surge Dips Esteemed listmembers, In gearing-up for testing under the auspices of EN61326:97, I'm trying to understand two immunity tests: EN61000-4-5 (surge immy) and -4-11 (dips immy). Is there test equipment one can rent to conduct these tests? What sort of mitigation steps are typical. Is anyone aware of any exceptions for this testing under ClassA rules? Thanks in advance... Wm Flanigan Standards Engineer Ameritherm Inc --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Pre-amps
David -- you are correct -- the mismatch in the system and antenna factors still remain, regardless of the cable length If the antenna (or whatever load) is not 50 ohms at some frequency, and the source feeding the antenna (or whatever) is 50 ohms at that frequency, a mis-match will exist. Adding 50 ohm cable between the source and load won't change the mis-match, but depending on the cable length, may make the mis-match look better or worse from the source end. (Unless, of course, the cable is infinitely long in which case it will look very much better, but normally, the cable length acts as an impedance transformer.) For specific frequencies, one could use the cable as an impedance matching section between the source and load, but this is clearly unusable for broad-band applications. Mike Hopkins -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, November 16, 2001 1:05 PM To: Pommerenke, David; 'ravinder ajmani'; marti...@appliedbiosystems.com Cc: emc-p...@majordomo.ieee.org Subject: Re: Pre-amps Note I am replying to all. What is the measurement inaccuracy associated with a mismatch if the transmission line is vanishingly short (relative to a wavelength)? -- From: Pommerenke, David davi...@ece.umr.edu To: 'Ken Javor' ken.ja...@emccompliance.com, 'Ravinder Ajmani' ajm...@us.ibm.com, marti...@appliedbiosystems.com Cc: emc-p...@majordomo.ieee.org Subject: RE: Pre-amps Date: Fri, Nov 16, 2001, 8:10 AM Dear Ken, I am thinking you are missing something (hope that I am correct). If you simply shorten the cable to zero, the problem of the missmatch, and the effect of an error that is not corrected for by the antenna factor still remains. David Pommerenke -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Thursday, November 15, 2001 5:51 PM To: Pommerenke, David; 'Ravinder Ajmani'; marti...@appliedbiosystems.com Cc: emc-p...@majordomo.ieee.org Subject: Re: Pre-amps If input VSWR for preamp and output VSWR for antenna are both bad, then it seems a simple solution is to connect preamp input to antenna output and let 50 Ohm output of preamp drive cable, solving two problems at once. Am I missing something? -- From: Pommerenke, David davi...@ece.umr.edu To: 'Ravinder Ajmani' ajm...@us.ibm.com, marti...@appliedbiosystems.com Cc: emc-p...@majordomo.ieee.org Subject: RE: Pre-amps Date: Thu, Nov 15, 2001, 7:49 AM On the amps: For emissions there are the following electrical criteria: - Noise figure expect about 4 dB for a broadband amp 30 MHz - 2 GHz. The noise figure is often larger at the lower frequencies if the amplifier goes up to many GHz. - Input SWR. This is important. Most broadband amps (especially if they go up to many GHz) have a bad input match at low frequencies. As the log-per antennas have a bad mismatch too, you will have multiple reflections on the cable between the antenna and the pre-amp. This reflections will influence your measurement and cannot be corrected for by the antenna factor. They may be as large as a few dB below 100 MHz. For that reason, you may be forced to add a 3 dB attenuatore at the antenna. This increases your noise figure by 3 dB. - Gain. Of course, you need only as much gain as is needed to overcome the cable loss (cable to the spectrum analyzer) and the noise figure of the spectrum analyzer. More gain will not help you. David Pommerenke -Original Message- From: Ravinder Ajmani [mailto:ajm...@us.ibm.com] Sent: Wednesday, November 14, 2001 1:27 PM To: marti...@appliedbiosystems.com Cc: emc-p...@majordomo.ieee.org Subject: Re: Pre-amps Joe, HP (Agilent) make good Pre-amps for different frequency ranges. If you are looking for an economical solution then you may try Com Power Corp. at (949) 587-9800. Regards, Ravinder PCB Development and Design Department IBM Corporation Email: ajm...@us.ibm.com *** Always do right. This will gratify some people and astonish the rest. Mark Twain MartinJP@appliedbiosyst ems.com To: emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@majordom Subject: Pre-amps o.ieee.org 11/14/2001 10:14 AM Please respond to MartinJP I am having some difficulties locating manufacturers that provide preamps with a 20-22dB gain. What manufacturer/model do you recommend? Why? Your assistance is appreciated. Regards Joe Martin Applied Biosystems --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our
RE: Safety Critical etc - the future
There are a few of us lurking in the background -- I'm on the US TAG for SC77A and SC77B (Immunity) as well as convenor of SC77B WG11 and member of WG9 and SC77A WG6. I'm constantly looking for industry input to the immunity standards and will present whatever information I receive, but that doesn't mean anything will happen -- quickly, slowly or at all. The WG's and TAG's I'm involved with are represented by a broad cross section of industry -- TAG's being US; WG's being international -- and many decisions become compromises in one way or another. Even if a WG KNOWS how to improve a standard technically, if it is going to involve companies buying new testers or modifying existing ones to meet the new requirements, the chances of getting published get much smaller.. Of the groups I'm part of -- for example WG11 -- only two members are independent test facilities. Others are industry -- Siemens, Philips, Nokia, IBM, Sun, HP, Schneider, Tele Danmark, Allen Bradley, Tokin, etc... Some of these experts run labs within their companies, but they are not NRTL's or Competent Bodies. This composition is similar in the other WG's I'm familiar with, as well as the US TAG's... Mike Hopkins Thermo KeyTek -Original Message- From: Scott Barrows [mailto:sbarr...@curtis-straus.com] Sent: Friday, November 02, 2001 2:18 PM To: geor...@lexmark.com Cc: emc-p...@ieee.org; Allen, John Subject: Re: Safety Critical etc - the future Hi All, With the remarks about this topic needing to be discussed in IEC and industry committees as well as between professionals, I think it may be time to inject that there are local Product Safety Societies (or the IEEE versions) that were formed for this particular reason. Perhaps the Engineers that sit on these TAG and TC committees should join up and take an ACTIVE role in these groups. With their participation in local safety societies, the entire industry will be represented and can be considered to have a voice in the development of standards and the considerations therein. I am not so sure that the NRTL's and Notified bodies should have the only voice in this process. Scott Barrows NPSS geor...@lexmark.com wrote: John, Allow me to comment further on this issue. I seem to remember a saying that goes The proof of the pudding is in the eating. By the same token, I have always expressed within my area of influence that the truest test of our internal ITE safety policies, practices and processes is field history. We all know that standards, like many other sets of knowledge, evolve from errors over time. Another saying that makes this point is Success comes from experience. Experience comes from failure. Overall, I believe the ITE industry has a superb safety record, given the exponential growth of this industry from corporate uses to homes, dorm rooms, etc. Hundreds of people are killed or injured every day in the use of various products, e.g. vehicles, farm equipment, firearms (hunting accidents), aircraft, etc. The majority of these are due to operator error and/or poor judgement. The more complex products are the ones more likely to develop a defect that could lead to deaths, e.g. aircraft. In the eight plus years I have been in product safety, I am not aware of a reported serious injury or death from the intended use or misuse of an ITE product. This does not mean there have been none, but it does mean that ITE is not a significant cause of injury or death. This is a result of fairly sound standards, common sense, experience, and due diligence in maintaining the original certified design of each product. We probably all know of improvements we would make in this process if we got to be king for a day. Most of us handle these as internal requirements beyond the imposed external requirements. The way we define and account for the use of safety critical parts is one small aspect of a much more complex series of processes leading to protecting ITE users from harm. George Alspaugh These are personal opinions only. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical
RE: Surge (1000-4-5) voltages impedances
Don't know the answer to the DC issue -- one would think the same would apply for AC or DC lines. I can confirm that the simulator source impedances are: AC lines normal mode - 2 ohms; AC lines common mode (line to ground) - 12 ohms; I/O lines - 42 ohms for the combination wave, but 25 ohms when using the communications surge wave... For shielded lines, the test involves running a surge current along the shielded cable between two pieces of equipment -- in this case, the impedance is very low, since all would normally be at ground potential. For other I/O line and telecom line tests, the tests are performed between lines, or line to ground, in which case the impedances will be higher -- up to several hundred ohms Hope that helps... Mike Hopkins Thermo KeyTek -Original Message- From: Yow, Steve (IndSys, GEFanuc, NA) [mailto:steve@gefanuc.com] Sent: Wednesday, October 10, 2001 10:00 AM To: 'EMC Post' Subject: Surge (1000-4-5) voltages impedances Group, Can anyone help me understand why the generic immunity (61000-6-2:1999) has the same voltage level (500V) for both common mode and differential mode for DC power input where as for AC power input it uses two different voltages ( 2kV for common mode and 1kV for differential)??I would think the DC requirement would look something like 1kV common and 0.5kV differential. (at least that is how table A.1 of 1000-4-5:1995 suggests). Is there any reasoning from someone one the TC for either the generic or test standard that could help explain. Also, could someone confirm that for power supply testing, differential mode uses lower impedance (2ohms) while common mode uses 12ohms. But for IO lines the impedance is 42 ohms no matter the coupling mode. True? For shielded communication lines, section 7.5 states surge applied to shield (common mode) with 2 ohm impedance, but Annex B states that a 42ohm impedance represents the source impedance between all other lines and earth. I understand informative annexes are just that and do not impose test requirements like the normatives. I can accept 2ohms, but did not know if there might be an explanation as to why they would differ? Regards, Stephen Yow GE Fanuc Automation P.O. Box 8106, Charlottesville, VA 22906 PH: (804) 978-5915Dial Comm: 292-5915 Fax: (804) 978-5102 Email: steve@gefanuc.com Web Site: http://www.gefanuc.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: ISO TR 10605 test setup (ESD)
Just one more comment: You never want a separate ground to a GRP that is different from other grounds in the building and more importantly, in the test area. There is a real risk of the GRP being at a different potential than other grounds, even if it is connected to a ground rod. Others have measured significant potentials between separate grounds in the same building.. Mike Hopkins KeyTek -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Tuesday, June 19, 2001 8:46 AM To: 'Chris Chileshe'; emc-p...@majordomo.ieee.org Subject: RE: ISO TR 10605 test setup (ESD) Hi from one Chris to another, I'm going to address your ground rod concerns (Question 3). In our lab here, we have a new building with new wiring and a reliable third wire Earth ground, so I simply tie my Ground Reference Plane (GRP) to the third wire of one of the AC outlets in the room. I have a cable from the GRP to the outlet with a ring lug. The ring lug is screwed to the ground connection with a lock washer and screw. I occassionally verify this ground connection with a ohmmeter. All devices under test are plugged into these same AC outlets (unless they're battery powered), so my GRP is common with all of my device under test Earth ground connections. If you used a doctored plug, the only concern that I would have would be with regard to the connection coming loose. However, I noticed that you're in the UK where they use that three pound broad sword for the AC ground terminal. It would probably take an earthquake to loosen that thing. But, I would still verify the connection with an ohmmeter. I have talked to many people about this; and this is the collective rationale that I have gathered. An ESD test setup needs to have a stable reference potential set by the GRP. The ESD gun's ground strap is tied to the GRP and all discharge potentials are then referenced to the GRP. Since the GRP is large and wide; it has low inductance along with a large amount of free space capacitance. The GRP is a very good high frequency ground potential. This means that the GRP's potential won't change much when the ESD current is bled into it. This keeps results repeatable. Just by having a GRP, you have satisfied 99% of the grounding requirements for a good ESD test . Now, why tie the GRP to Earth? The GRP's connection to Earth ground serves two purposes. It is a low frequency ground connection to ensure that, over time, the GRP's DC potential won't change with respect to Earth ground. The GRP's Earth ground connection also ensures that the GRP has a low frequency common with any Earth grounds that the device under test may have. It is my belief that you don't need a dedicated ground rod for your ESD setup to satisfy this requirement. My opinions only; not to be confused with fact, company policy or gospel under any circumstance :-) Chris Maxwell Design Engineer - NetTest Optical Division email chris.maxw...@nettest.com phone +1 315 266 5128 fax +1 315 797 8024 NetTest 6 Rhoads Drive, Utica, NY 13502 USA web www.nettest.com -Original Message- From: Chris Chileshe [SMTP:chris.chile...@ultronics.co.uk] Sent: Tuesday, June 19, 2001 5:22 AM To: emc-p...@majordomo.ieee.org Subject: ISO TR 10605 test setup (ESD) Hi group For those of you unfamiliar with ISO TR 10605, it is the ESD test standard for automotive electronics (8kV contact, 25kV air). I am trying to perform quick ESD tests on a product which has bottom entry proprietary cable. Picture if you an upside-down bottle of coke with push buttons at the top and cable entry at the bottom end. The cable itself is screened multicore with a molded end connector so there is a minimum length it must protrude from the product before it even thinks about bending. This is about an inch and a half (about 40mm). According to ISO TR 10605, if insulation is required under the EUT, the insulation must support the EUT some 25mm above the ground plane. Question 1: Does this insulation have to be 25mm thick or can I make a table like structure with thinner insulating sheet and supporting pillars at the corners? Question 2: Would a more 'compliant' test set-up have the bottle of coke lying on its side rather than standing vertically as it would in practice? The setup for the ESD test shows a ground strap connect the plane to a grounding rod. We had a specialised ESD test area where I worked before but we took everything for granted and didn't really bother finding out where or how the ground connection was made! Question 3: Can I connect the ground strap via say a UK 3-pin plug (with live and neutral prongs removed) into a mains socket or is this asking for trouble (RCD's etc). Grateful for any advice Regards - Chris Chileshe _ This message has been checked for all known viruses by Star
RE: Typing Shortcuts
How about By The Way Mike Hopkins KeyTek -Original Message- From: rehel...@mmm.com [mailto:rehel...@mmm.com] Sent: Wednesday, June 13, 2001 12:18 PM To: emc-p...@majordomo.ieee.org Subject: Typing Shortcuts Over time I have come across many typing shortcuts using the English language, such as: OTOH - on the other hand WRT - with regard to BTW - (I am still trying to figure out this one) Can someone please list the more common ones? I sometimes strain my brain trying to figure them out and they are in my own language. It must be terribly confusing to most of our world-wide colleagues. Thanks, Bob Heller 3M Product Safety, 76-1-01 St. Paul, MN 55107-1208 Tel: 651- 778-6336 Fax: 651-778-6252 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: ESD generators max Contact discharge level
Another point is that at lower voltages, the real rise times (the dv/dt) can be quite a bit higher --- especially below about 5kV Mike Hopkins KeyTek -Original Message- From: Cortland Richmond [mailto:72146@compuserve.com] Sent: Wednesday, April 25, 2001 2:33 AM To: jrbar...@lexmark.com; ieee pstc list Subject: Re: ESD generators max Contact discharge level Lower voltages, because of less corona, tend to have more energy, sooner, relative to the total. You might pass a 15 kV air discharge test -- but fail, lower. We ALWAYS want margin, and others ALWAYS want none. My experience in a previous area of the industry is, this lasts until a rash of field failures costs someone a lot of money. The nature of the contact discharge test is such that the charge is not even applied to the electrode until it's in position, and then, humidity is not a factor. However, in a dryer atmosphere, you might experience more FIELD failures, since people using the equipment will be charging up to higher voltages. You have a good point, though; for the reason you mention, there is a limit on humidity for doing ESD testing, which I believe is 70 percent -- my references are at the office and I'm at home. Cortland --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: consumer electronics used on board aircraft
That might be right, but if the FCC didn't ban the use of cell phones in airplanes, I'd bet the airlines or FAA would. Mike Hopkins -Original Message- From: rbus...@es.com [mailto:rbus...@es.com] Sent: Thursday, January 25, 2001 12:26 PM To: emc-p...@majordomo.ieee.org Subject: RE: consumer electronics used on board aircraft I may regret saying this, but isn't it conceivable that the FCC Rules that make it illegal to use a cell phone in the air has more to do with the right of the airline to sell expensive phone time, than the technical issues? :( -Original Message- From: Brent DeWitt [mailto:bdew...@ix.netcom.com] Sent: Thursday, January 25, 2001 10:08 AM To: Mike Hopkins; 'Colgan, Chris'; 'Emc-Pstc' (E-mail) Subject: RE: consumer electronics used on board aircraft My background is the pretty much the same as Mike's, which is probably why I agree with his response. I just wanted to add that the prohibition on cell phone usage (in the US at least) is not FAA or airline driven, but mandated by the FCC. The architecture of the cellular system is rather carefully planned. The placement of antenna sites, coverage and hand-off algorithms are based on the propagation from land based phones, which is quite different from a phone in an airliner 25000' feet up. The FCC has therefore made it illegal to operate a cell phone after the wheels of the plane leave the ground. Regards, Brent DeWitt Takeoffs are optional. Landings are mandatory -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Mike Hopkins Sent: Wednesday, January 24, 2001 11:38 AM To: 'Colgan, Chris'; 'Emc-Pstc' (E-mail) Subject: RE: consumer electronics used on board aircraft As a frequent flyer and private pilot with some knowledge of EMC, I'll throw in a few comments: It is clear to me that consumer electronics can interfere with aircraft electronics, and I've probably heard all the same horror stories -- DC10 finds itself off course on landing, false engine warnings, interrupted communications, etc... It isn't clear to me how prevalent this problem is or if it happens often enough to be considered a problem. One instance of electronic interference is enough to have everyone up in arms against the use of ANY electronics in ANY airplane. On a 747 flight to the Pacific, I'd bet there are as many as 30 to 40 lap top computers operating together at some point during the flight. Additionally, there are probably another 40 to 50 walkman tape players or CD players in operation, plus the on-board entertainment systems and a few in-flight telephones being used. On shorter flights, there may still be a large number of laptops being used by business people plus tape/CD players and air phones and the like in use during the flight. I don't think this is a general problems for aircraft electronics. HOWEVER; if radio or television receivers or cell phones were allowed, I believe the level of interference could easily reach the level of being at least disruptive to aircraft systems if not downright dangerous. I have personally seen commercial scanners and FM broadcast receivers that will interfere with voice comms -- 118MHz to 136MHz -- which means they could certainly interfere with nav equipment operating between 108MHz and 118MHz (VOR's and ILS's, specifically). I also have a Garmin hand held GPS system that I cannot find anything that it will interfere with nor have I found anything that interferes with it (except things getting in the way of the antenna - Maybe I'm just lucky?). My sense is the following: Interference with nav stuff is the most likely -- a VOR indicator off, or something like that. With GPS back-up (or getting to be primary) in most aircraft, a faulty Nav indication would likely be caught before it was a problem (NOT so if you're on an ILS approach in IMC (Instrument meteorological conditions) where a faulty indication can run you into terrain -- this is why no electronics should be operated on the aircraft below 10,000 feet on take-off or approach). I doubt a cell phone caused the Saab to crash -- most airplanes will still fly even with all electronics blocked out (don't know if the Saab is fly by wire or not, but I don't think so). Horizontal situation indicators and gyro's are driven by vacuum and in larger airplanes, there's back-up vacuum, red flashlights in the cockpit, etc... Upsetting autopilot controls might cause the airplane to do something erratic, but that sort of thing should be recoverable as long as someone in the cockpit is paying attention. Enough of that -- need to get back to my real job Mike Hopkins KeyTek -Original Message- From: Colgan, Chris [mailto:chris.col...@tagmclarenaudio.com] Sent: Wednesday, January 24, 2001 6:15 AM To: 'Emc-Pstc' (E-mail) Subject: consumer electronics used on board aircraft There is growing concern amongst professional aircrew about the use of consumer electronics (CD players
RE: consumer electronics used on board aircraft
As a frequent flyer and private pilot with some knowledge of EMC, I'll throw in a few comments: It is clear to me that consumer electronics can interfere with aircraft electronics, and I've probably heard all the same horror stories -- DC10 finds itself off course on landing, false engine warnings, interrupted communications, etc... It isn't clear to me how prevalent this problem is or if it happens often enough to be considered a problem. One instance of electronic interference is enough to have everyone up in arms against the use of ANY electronics in ANY airplane. On a 747 flight to the Pacific, I'd bet there are as many as 30 to 40 lap top computers operating together at some point during the flight. Additionally, there are probably another 40 to 50 walkman tape players or CD players in operation, plus the on-board entertainment systems and a few in-flight telephones being used. On shorter flights, there may still be a large number of laptops being used by business people plus tape/CD players and air phones and the like in use during the flight. I don't think this is a general problems for aircraft electronics. HOWEVER; if radio or television receivers or cell phones were allowed, I believe the level of interference could easily reach the level of being at least disruptive to aircraft systems if not downright dangerous. I have personally seen commercial scanners and FM broadcast receivers that will interfere with voice comms -- 118MHz to 136MHz -- which means they could certainly interfere with nav equipment operating between 108MHz and 118MHz (VOR's and ILS's, specifically). I also have a Garmin hand held GPS system that I cannot find anything that it will interfere with nor have I found anything that interferes with it (except things getting in the way of the antenna - Maybe I'm just lucky?). My sense is the following: Interference with nav stuff is the most likely -- a VOR indicator off, or something like that. With GPS back-up (or getting to be primary) in most aircraft, a faulty Nav indication would likely be caught before it was a problem (NOT so if you're on an ILS approach in IMC (Instrument meteorological conditions) where a faulty indication can run you into terrain -- this is why no electronics should be operated on the aircraft below 10,000 feet on take-off or approach). I doubt a cell phone caused the Saab to crash -- most airplanes will still fly even with all electronics blocked out (don't know if the Saab is fly by wire or not, but I don't think so). Horizontal situation indicators and gyro's are driven by vacuum and in larger airplanes, there's back-up vacuum, red flashlights in the cockpit, etc... Upsetting autopilot controls might cause the airplane to do something erratic, but that sort of thing should be recoverable as long as someone in the cockpit is paying attention. Enough of that -- need to get back to my real job Mike Hopkins KeyTek -Original Message- From: Colgan, Chris [mailto:chris.col...@tagmclarenaudio.com] Sent: Wednesday, January 24, 2001 6:15 AM To: 'Emc-Pstc' (E-mail) Subject: consumer electronics used on board aircraft There is growing concern amongst professional aircrew about the use of consumer electronics (CD players, mobile phones, hand held GPS etc) on board aircraft. Some claim that passenger electronics has definitely interfered with navigation systems, primary flight displays or engine warning systems. There are rumours that a mobile phone contributed to the demise of a Crossair Saab 340 on 10 Jan 2000 killing all passengers and crew. Some pilots reckon that it is absolute nonsense. Knowing what you do, about how EM disturbance can affect electronics equipment, that it is almost impossible to make electronics equipment completely immune to EM effects, that FCC class B or CE marked equipment has not been tested (presumably) with avionics in mind etc, etc, how do you feel when the guy next to you on your flight gets his Minidisc player or laptop out? Remember, when you are descending through a cloud layer, the pilot is relying solely on electronics receiving equipment to get the aircraft on the runway. Do you think all consumer electronics should be banned from aircraft, that FCC or CE equipment is okay or that the whole issue is scaremongering piffle. Any comments gratefully received, I will post a summary on a professional pilots forum and let you know that results. Regards Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclarenaudio.com * http://www.tagmclarenaudio.com ** Please visit us at www.tagmclarenaudio.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error
RE: EN 61000-4-8
The issue is getting the required field strength: 1A (roughly) through a 1m coil will produce about 1A/m field in the center of the coil. Anything bigger than .3m in any dimension, won't be stressed adequately. For bigger stuff, you need a bigger coil, but the problem is you then need more current to get the same field strength: a 2m coil requires 2A, etc... Using multiple turns allows you to keep the current down. For a 1 meter coil, you can get 1A/m from a current of roughly 0.5A. The numbers don't exactly work because of losses in the coil: The coils we buy have a coil factor of about .85, which means they are 85% efficient and you need about 15% more current to get the correct fields. Other coils will have other factors, depending on their design. You can call Fischer Constant Communications -- I believe they've made some very big coils for some customers: FCC 2905 W. Lomita Blvd. Torrance, CA 90505 Tel: 310 891 0635 Fax: 310 891 0644 Hope this helps, Mike Hopkins KeyTek -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Tuesday, January 16, 2001 11:42 AM To: emc-p...@majordomo.ieee.org Subject: EN 61000-4-8 We will have to apply the magnetic field immunity test to some of our Generic and ITE products in order to comply with the new revisions of the standards. One of the tests is not clear to us. Consider a product whose width and depth are such that it fits correctly inside the standard 1 m loop, but also assume that the equipment height exceeds 0.5 m. On one hand, the standard tends to indicate that a two or more loops are required to ensure that the entire height of the equipment is immersed during a single test. But on the other hand, there is mention of moving a single loop over the height of the equipment. Do I understand correctly, that tall ( 0.5 m) equipment may be tested using a single 1 m loop that is moved along the height of the equipment? Richard Woods --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN 61000-6-2 Table 2.3 inticates signal ports = 30 M +/- 1k v?
You read the table correctly, and it seems to be confusing a lot of people. To go through it logically (I think) The longer the line, the more likely surge energy would be coupled into a cable -- certainly the case for induced lightning transients. Terminated lines shorter than a few meters are not likely to pick up much energy from lightning but keep in mind the old lineman's rule of thumb that says 1kV across 1 meter or unterminated wire, 1 mile from the flash! Hence, protecting inputs connected to long lines against surges makes sense, whether they go outside a building or not. If you wrap a mile of wire (data cable) around a high rise building, I would argue you have just constructed a lightning antenna. In residential structures, there is no building steel to help with shielding or grounding, so you might as well be outside for purposes of coupling a transient into your system. It follows that the IEC or EU would require surge testing long I/O lines. Problem is: IEC wants to insure no upset or loss of operation, which means testing the product live, with data flowing. This requires some kind of coupler/decoupler in series with the line to the equipment being tested. Works okay for slower data rates (~100kHz), but no one has yet designed a coupler/decoupler that works at the higher data rates that exist today. Using existing coupler/decoupler designs will insure loss of data; hence, the unless normal functioning cannot be maintained because of the impact of the CDN on the EUT clause applies. Not sure I understand the reasoning, but if you get a real live surge from the real world, data will certainly be interrupted as well. Reality is: if you want to insure minimum loss of function on a long I/O line, you really want to know if the inputs are protected adequately, and you can do this without a coupler/decoupler. Bellcore, CCITT, FCC and others all surge test inputs directly without any data (knowing full well that during the surge event, data will be interrupted anyway) then connect the line and see if the input circuitry is still functioning. In the course of revising IEC 61000-4-5 for surge, it's this last paragraph that I'm pushing for. That gets rid of the coupler/decoupler design problem and provides a way of establishing a basic level of immunity for any kind of I/O or telecom line. Hope this helps, Michael Hopkins KeyTek (also, convenor SC77B WG11 responsible for the revision of 61000-4-5, so if you have anything to contribute, let me know) -Original Message- From: Terry Meck [mailto:tjm...@accusort.com] Sent: Friday, January 05, 2001 9:23 AM To: emc-p...@ieee.org Subject: EN 61000-6-2 Table 2.3 inticates signal ports = 30 M +/- 1kv? If I read the EN 61000-6-2 correctly Table 2.3 indicates signal ports = 30 M must be tested +/- 1000 surge unless normal functioning cannot be maintained because of the impact of the CDN on the EUT This surprises and confuses me since I thought this would be imposed only on cables leaving a building. Any insight on this will be appreciated? Best regards, Terry J. Meck Senior Compliance/Test Engineer Phone:215-721-5280 Fax:215-721-5551 hard copy; Fax PC: 215.799.1650 To my desk PC tjm...@accusort.com Accu-Sort Systems Inc. 511 School House Rd. Telford, PA 18969-1196 USA --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
CEPT Standards
I've had a request to meet CEPT T/TR 02-02E, but can find no references to this. I found the CEPT web site, but they don't mention any standards at all. Can only find references to radio conferences, postage stamps and amateur radio -- nothing specific to testing products. Anyone out there have any information that would at least tell me what this is ?? Thanks,,, Best Regards for the New Year, Michael Hopkins mhopk...@keytek.com Tel: 1-800-753-9835 Fax: 1-978-275-0850 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Surge (immunity) requirement for equipment in telecommunicati on c enters
I wasn't involved with the development of the surge requirements for 10m cables but not shorter, but I do remember some of the rational: Compared to other phenomena in EMC, surges are relatively slow and consist of energy at primarily at frequencies of a few MHz, as opposed to hundreds of MHz or even GHz for EFT and/or ESD events. As a result, pick-up of radiated energy at these low frequencies by short cables is minimal and not considered to be a problem; however, as the cables get longer, it gets more and more likely that significant energies can be induced into cables from slow surge events, such as distant lightning or other switching transients. Whether the cable is inside or outside doesn't matter: very long cables inside a high rise building are just as an effective at picking up energy from nearby lightning as telephone lines strung horizontally outside a building. As a side note, there used to be an old lineman's rule of thumb: 1kV per meter per mile -- In other words, it is possible to develop 1kV across a meter of unterminated wire a mile from the flash. I have no idea how accurate this is, but it was commonly used in the 60's and 70's. Anyway -- the basic idea is that shorter cables won't pick-up any significant energy from a radiated surge event. Hope this helps, Mike Hopkins -Original Message- From: Zohar Zosmanovich [mailto:zohar_zosmanov...@radwin.com] Sent: Wednesday, December 20, 2000 6:47 AM To: 'emc-p...@majordomo.ieee.org' Subject: Surge (immunity) requirement for equipment in telecommunication c enters Hi, The EN 300 386 (EMC requirements for telecommunication network equipment) require to perform a surge of 1.2/50 Tr/Th us, 0,5 kV to ports for indoor signal lines (in telecommunication centers), when cables longer than 10 m are connected ! Can some one explain my the rational of divided up to 10 m and more than 10 m, anyway all cable is in the building (indoors) ? Zohar (Jana) Zosmanovich Compliance Engineer, RADWIN ltd. 34 Habarzel St., Tel Aviv 69710, Israel Tel.: 972-3-7666735 ; Fax: 972-3-7657535 Email: mailto:zohar_zosmanov...@radwin.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Crossed Vane ESD Simulator
Hi Sandy -- KeyTek built many of the crossed vane testers used by IBM and their suppliers. Older units (pre 1980's) were built by another company -- don't remember who. The crossed vane tester produces a ringing waveform which more closely resembles the kind of waves you would see from a furniture ESD event - one large charged metal object bumping into a product (computer mainframe). The current peaks are much higher than from human ESD. The vanes themselves are radiators -- they radiate like an antenna when the field collapses, and this is, in fact, part of the ESD test. It's been a while, but as I remember, there were two modes of operation: 1) discharge probe is placed in direct contact to metal on the unit under test. ESD current injection and radiation from the vanes takes place. 2) discharge probe is placed in direct contact with the ground below the vanes. This is a radiated test only (each time a discharge is made to ground, the vanes radiate. The other thing I remember from being around these units is that they radiate quite a strong field -- we took down an HP mainframe computer located in an adjacent room during the days when we were developing this unit. Injected currents are quite high -- I could dig out some old literature if you're interested. Hope this is helpful. Michael Hopkins KeyTek mhopk...@keytek.com -Original Message- From: Sandy Mazzola [mailto:mazzo...@symbol.com] Sent: Monday, December 18, 2000 7:13 PM To: emc-p...@ieee.org Subject: Crossed Vane ESD Simulator To all, I am looking for information on a Crossed Vane ESD simulator. Specifically looking for what the vanes are for and how they affect the results and is the position of the ESD simulator probe significant, should it be on the edge of the table or near the unit. Any information on Crossed Vane ESD Simulators would be appreciated. Thanx a lot Have a great day Sandy Mazzola Regulatory Engineer Symbol Technologies Inc 1 Symbol PLaza Holtsville, N.Y 11742-1300 Phone (631) 738-5373 Fax (631) 738-3318 or (631) 738-3915 E-mail: mazzo...@symbol.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Standards
Theoretically Already we have EN's that are NOT identical with the IEC standards What's the odds of the EU (CENELEC) coordinating closely with IEC on these issues?? I'd say close to zero -- as convenor of IEC SC77B WG11 responsible for such things as Surge and EFT immunity standards, and as a member of WG9 responsible for ESD immunity standards, I can tell you these documents are all in the process of revision and I know of no mechanism in place to insure the equivalent EN's are revised at the same time. Anyone out there have better information? I'd like to think there is a way of coordinating these things, but.. Michael Hopkins mhopk...@keytek.com -Original Message- From: Finn, Paul [mailto:fi...@pan0.panametrics.com] Sent: Monday, December 18, 2000 4:14 PM To: 'emc-pstc' Subject: Standards Please bear with me on this one, this is not my strong point. I am under the impression that the EN standards are derived from thier IEC equivalent. Also for compliance with the EMC directive we test to the applicable EN standard. When the IEC version(s) are amended is it safe to assume that the equivalent EN will be amended? Alternatively is it possible the EN already includes the IEC amendments? Any comments would be greatly appreciated. Paul Finn, Manager Test and Certification Group Panametrics Inc. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Blocking Cap for 1000-4-4 (EFT)
Virtually all commercially available EFT simulators with built-in coupler/decouplers for the ac mains contain the 33nF capacitors internally. The only reason you might need to use them externally is if you were building your own coupler/decoupler, which also includes the necessary backfilter components to allow voltages to be developed and to protect other equipment connected to the same mains. I'm quite surprised by Schaffner's response to you According to their own literature, the Model NSG 3025 is designed to allow EFT tests to be run on live AC or DC mains using a built-in coupling network (this was taken from their web page some time ago -- the product seems to have been removed from their offering judging by their new web site design. At least I can't find it anymore.). Since IEC 61000-4-4 (and I believe all earlier versions) require the use of a 33nF coupling capacitor, I'd be amazed if they actually used a capacitor that was not in compliance with the standard. Also, from looking at a picture of the product, there is obviously an ac connector on the front panel -- I would assume to which you would connect the product under test. I'm not even sure where one would connect an external capacitor ? I suggest you call them again and this time try and find someone who actually understands the product. Best of luck,,, Michael Hopkins KeyTek -Original Message- From: Antonio Cinquino [mailto:cinqu...@cae.ca] Sent: Tuesday, December 05, 2000 8:46 AM To: 'emc-p...@ieee.org' Subject: Blocking Cap for 1000-4-4 (EFT) Hello Group, Question with regards to EFT Immunity testing on power lines. We have a post installation setup that allows for only the direct injection EFT method described in IEC-1000-4-4. A figure is given on page 49 (figure 10). We will use a 2kV test level. Anyway, my question concerns the 33nF blocking capacitor. The figure says to use them if necessary. I'm assuming that depends on if your EFT generator has in-built protection or not. We use the NSG 3025 from Schaffner. Phoned them, and they said to use the caps. Now, should the caps withstand a working voltage of 2kV (peak)? Or should it have a dielectric strength that withstands 2 kV? (I assume that dielectric testing by the manufacturer is done for a very short duration whereas our EFT testing will last for about 1min for each polarity) Are there any other factors to consider in selecting the capacitor, given the type of waveform going through? I've tried a few manufacturers and have had problems up to now finding the right cap. If anyone can suggest a North American Vendor, and even go as far as suggesting the capacitor type then I would really appreciate it. I know it's just a cap :) Maybe I'm over complicating the matter. Anywho looking forward to hearing your responses. Regards Antonio Cinquino CAE Electronics Ltd. Electrical System Designer Phone : (514) 341-2000 (ext. 4303) Fax : (514) 340-5552 Email : cinqu...@cae.ca mailto:cinqu...@cae.ca --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: How does RF travel through outer space?
An excellent explanation -- I've seen these issues explained many times, either over simplified or overly detailed. The explanation below is a superb balance. Thanks Michael Hopkins KeyTek -Original Message- From: Nick Rouse [mailto:100626.3...@compuserve.com] Sent: Thursday, November 30, 2000 9:06 PM To: brian_kunde Cc: EMC Subject: Re: How does RF travel through outer space? RF, meaning radio frequency radiation, is electromagnetic radiation just like light. At the classical level this can be thought of as an electrostatic field that is in a direction that is at right angles to the direction the radiation is propagating. Coupled to this is a magnetic that is at right angles to the electric field and the direction of propagation. If you stand at one point, the strength of the both the electrostatic and magnetic fields vary sinusiodally with time. The number of times a second the fields swing through a full cycle (positive, negative and back to positive or north, south and back to north) is called the frequency. If you examine the fields at different points in space at any one instant you find the strength varies sinusoidally along the direction of propagation. The distance between peaks is called the wavelength. A simple way to think about the radiation is to consider that the changing fields induce each other, the changing magnetic field induces the electrostatic field and the changing electrostatic field induces the magnetic field. Since both electrostatic and magnetic fields contain energy this radiation contains energy. As long as nothing absorbs the energy of the two fields this process continues in a self sustaining way and the radiation propagates energy through whatever medium it is in. A more sophisticated explanation comes from solving the differential vector equations for electricity and magnetism that James Clerk Maxwell developed. These have a solution in the form of a propagating wave. You can add various layers of sophistication to this. You can include the fact that the energy associated with these fields cannot be increased in a completely smooth manner but must increase in small jumps or quanta. Incorporating this will give the Schrödinger equation and adding the effects of special relativity will give Dirac's equations in spinor form that are at the heart of quantum electrodynamics (QED), our best theory. There are no known circumstances in which this theory can be applied and in which the experimental results are in conflict with the predictions of this theory. Returning to more simple matters; if you can convince yourself that electrostatic fields and magnetic fields operate in a vacuum them you should not have too great a difficulty accepting that electromagnetic radiation can propagate through space. It is fairly easy to show that these fields do operate in a vacuum. The gold leaf electroscope, beloved of primary level physics lessons, works just as well if you pump the air out of the conical flask it is traditionally set up in. A steel ball slid gently into the vacuum flask you use for picnics can be moved around by a magnet outside the flask with the magnetic field operating through the vacuum. These fields (or the equivalent quantum mechanical variable) are all there is to electromagnetic radiation. They are not some extra bit added on to the 'real' nature of radio, x-rays, light etc. The strength, frequency, direction etc. of these fields give all the properties of these effects. Electromagnetism is a single phenomena. The range of frequencies that have been observed cover 36 orders of magnitude. Not surprisingly the properties vary enormously over this expanse but the variation is smooth and continuous. There are no real boundaries. The limits given in books for x-rays infra-red and the like are as arbitrary and man made as country and state borders. Light is only special in that man has evolved organs that are sensitive to electromagnetic radiation with frequencies in the range of about 430 to 850 THz and sensing such radiation gave it a name. Even here the boundaries are fuzzy. The sensitivity of the eye peaks in the middle of that range and tapers away at the ends in a bell shaped curve with no absolute limit and variation between individuals. Having said that you should be able to accept that electromagnetic radiation propagates though a vacuum I should say that in the ninetieth century many imagined that light must propagate through something. Since it had a fixed velocity it must be a velocity with respect to something. An all pervasive 'luminiferous ether' was postulated as the fixed reference for this velocity. However the famous experiment of Michelson and Morley in 1881 showed practically, and Einstein's special relativity of 1905 explained theoretically, that electromagnetic radiation propagates at the same speed with respect an observer irrespective of whether that observer is moving towards or away from the source of that radiation.
RE: Immunity measurement uncertainty
Don't know about the others, but the ESD Association has done some work on ESD uncertainties. I don't know if it's published yet (I don't think so) but there is a meeting in Anaheim on Sunday the 23rd. I have some drafts, but need to see if they are the final ones and if I can broadcast the info yet.. Best Regards, Mike Hopkins -Original Message- From: Leslie Bai [mailto:leslie_...@yahoo.com] Sent: Thursday, September 14, 2000 4:24 PM To: IEEE EMC-PSTC (E-mail) Subject: Immunity measurement uncertainty Hello, members, Is there anyone who can direct me to somewhere I can find the method to derive the Immunity Test Uncertainties, e.g. ESD, RI, EFT/B, Surge, etc. Thanks, Leslie __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Ringing wave surge testing for Modem
Also, refer to IEC 61000-4-5 section on telecom and FCC Part 68 for surge testing modems. Mike Hopkins KeyTek -Original Message- From: j...@aol.com [mailto:j...@aol.com] Sent: Monday, September 11, 2000 11:19 AM To: matt.aschenb...@echostar.com; emc-p...@majordomo.ieee.org Subject: Re: Ringing wave surge testing for Modem In a message dated 8/31/00, Matt Aschenberg writes: The fast transient has a ringing (underdamped) wave form. Our primary concern is to protect the modem against lightening surges. We currently test to 6kV underdamped and overdamped. Hi Matt: If your primary concern is lightning immunity, you should probably refer to some industry standards that address this specific topic. In most cases the peak voltage of the surge is limited to less than 1500 volts by the primary protector located where the cable enters the building. However, the peak currents can reach 100 amps, and the total durations can reach 1000 uS. In other words, there is still a lot of energy to deal with. You do not mention the equipment you are using to generate the surges, but if it was not designed specifically for simulating lightning surges, it probably does not generate enough energy to accurately simulate lightning. Two references that describe recommended immunity tests for lightning are ITU-T K.21 and Bellcore/Telcordia GR 1089-CORE. When you develop your lightning protection scheme for the modem, keep in mind that the same circuit must also meet the power cross requirements in UL 1950 (if the product will be used in the North America). You will find that the UL 1950 compliance and lightning immunity are somewhat at odds with each other, so it takes a well thought out design to perform well for both tests. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. http://www.randolph-telecom.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: 90 V gas-filled arrestors source?
You can also get coupler/decouplers that meet the spec from KeyTek (1-800-753-9835) and other manufacturers. Mike Hopkins KeyTek -Original Message- From: Dan Kinney (A) [mailto:dan.kin...@heapg.com] Sent: Friday, September 08, 2000 1:37 PM To: David Gelfand; emc-p...@majordomo.ieee.org Subject: RE: 90 V gas-filled arrestors source? Schaffner does. They can be reached at 800-367-5566 or 732-225-9533. Dan Kinney Horner APG -Original Message- From: David Gelfand [SMTP:gelf...@memotec.com] Sent: Friday, September 08, 2000 10:07 AM To: emc-p...@majordomo.ieee.org Subject: 90 V gas-filled arrestors source? Hello group, Does anyone know who makes gas-filled arrestors called for in IEC 1000-4-5 coupling networks? Would a MOV be ok? Thanks, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: 90 V gas-filled arrestors source?
An MOV won't work - it's a clamping device as opposed to a crowbar device. Gas filled arrestors are common in the telecom industry -- try CP Clare, Reltech (near Chicago), TII New York, Sankosha, Shinko, --- probably others, but can't remember them. Good luck Mike Hopkins KeyTek -Original Message- From: David Gelfand [mailto:gelf...@memotec.com] Sent: Friday, September 08, 2000 11:07 AM To: emc-p...@majordomo.ieee.org Subject: 90 V gas-filled arrestors source? Hello group, Does anyone know who makes gas-filled arrestors called for in IEC 1000-4-5 coupling networks? Would a MOV be ok? Thanks, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada
RE: Heavy Industrial vs. Light Industrial
The Generic standards for industrial and residential contain definitions: Industrial (from EN 50081-2) Industrial locations are characterized by the existence of one or more of the following conditions: - industrial, scientific and medical (ISM) apparatus are present - heavy inductive or capacitive loads are frequently switched; -currents and associated magnetic fields are high. These are the major contributors to the industrial electromagnetic environment and as such distinguish the industrial from other environments. Residential, commercial and light industry (from EN 50082-1) The environments encompassed by this standard are residential, commercial and light-industrial locations, both indoor and outdoor. The following list, although not comprehensive, gives an indication of locations which are included: - residential properties, e.g. houses, apartments; -retail outlets, e.g. shops, supermarkets;' -business premises, e.g. offices, banks; -areas of public entertainment, e.g. cinemas, public bars, dance halls; -outdoor locations, e.g. petrol-stations, car parks, amusement and sports centres; -light -industrial locations, e.g. workshops, laboratories, service centres. Locations which are characterized by being supplied directly at low voltage from the public mains network are considered to be residential, commercial or light industrial. How's that?? Mike Hopkins, KeyTek -Original Message- From: don_macart...@selinc.com [mailto:don_macart...@selinc.com] Sent: Friday, July 28, 2000 11:40 AM To: emc-p...@majordomo.ieee.org Subject: Heavy Industrial vs. Light Industrial I'm looking for a good definition of what a typical heavy and light industrial environment is. Is there an official definition? If so, where can I obtain it? Thanks, Don --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Electrical safety of firearms
My favorite is the light bulb and socket - simply changing a light bulb is inherently unsafe.. Mike Hopkins -Original Message- From: Peter Tarver [mailto:ptar...@nortelnetworks.com] Sent: Thursday, July 27, 2000 12:08 PM To: emc-p...@majordomo.ieee.org Subject: RE: Electrical safety of firearms Other inherently unsafe products: three-ring binders (mechanical hazard) any pointed writing implement (mechanical hazard) plain old mechanical staplers (mechanical hazard) paperweights (mechanical hazard) pushpins (mechanical hazard) bath tubs and swimming pools (drowning hazard) in-sink garbage disposals (mechanical hazard) refrigerators and freezers (suffocation hazard) Some of which, UL will List. Regards, Peter L. Tarver -Original Message- From: Peter Merguerian Rich, I tried to List such a device with UL some time ago and they told me that they could not List because it is inherently unsafe! However, I succeeded in getting TUV GS for the system.
RE: EFT/Burst
You are correct for purposes of COMPLIANCE to EN55024 and application of a CE Mark, you test each line with respect to a reference ground (PE), but as I'm sure you're aware, a customer can ask for whatever they think is relevant. Mike Hopkins mhopk...@keytek.com -Original Message- From: Roncone Paolo [mailto:paolo.ronc...@compuprint.it] Sent: Wednesday, June 07, 2000 11:46 AM To: 'emc-p...@ieee.org' Subject: EFT/Burst Group, we are currently discussing with one OEM the interpretation of EFT/Burst test requirements per EN55024 and EN61000-4-4 to a printer. Specifically we are discussing the requirements of application of bursts to AC power lines. Our understanding is that they must be applied between each (single) power supply conductor and reference ground (or protective earth), as specified in EN61000-4-4 section 7.3.1. Also fig.4 and fig.11 in the same document seem to confirm this. Our OEM customer says that all combinations of phase, neutral and protective earth should be tested. They actually tested both singular AC lines and also more than one AC line. The printer passed the test in the first mode and failed in the second mode. Any comments / interpretations would be highly appreciated. Paolo Roncone Compuprint s.p.a. Italy --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EMC vs. Exi equipment
Not sure I understand what a zener barrier is, but if you mean there are zener diodes across the line or even in series with the line, this has no bearing on the applicability of 61000-4-5. IEC 61000-4-5 is a method of surge testing a product without regard to the signal line type, data, construction or anything else. It simply assumes all products are black boxes with inputs and outputs for power and data. There are problems with surge testing I/O lines -- couplers that don't work on lines with high data rates, etc but these issues will be dealt with in future revisions (don't hold you breath waiting... the process of revision has just begun in my Working Group and it will probably be a few years before any published revisions appear!). Best Regards, Michael Hopkins Convenor IEC TC77B WG11 -Original Message- From: Westin, Amund [SMTP:amund.wes...@dnv.com] Sent: Thursday, May 11, 2000 4:15 AM To: 'emc-pstc' Subject: EMC vs. Exi equipment Hello members, One question, what's common practise regarding surge test (EN61000-4-5 on signal lines) on lines which contains zener barriers ? Have a feeling that the surge test is not applicable. Comments ? Best regards Amund Westin Det Norske Veritas * amund.wes...@dnv.com ** Neither the confidentiality nor the integrity of this message can be guaranteed following transmission on the Internet. This message has been swept by MAILsweeper at DNV for the presence of computer viruses. ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Surge
I don't know if you tried to contact KeyTek or not, but we have both applications people and engineers who understand the ECAT system in detail. It is still our primier Surge tester and has evolved significantly with new capabilities and enhancements on a regular basis. To take your issues one at a time: However, I do not fully understand the discharge network and do not know, for instance, if the total joules delivered to the coupler is independent of load or impedance. Energy delivered works like power: The maximum energy you can deliver to a load is when you have matched conditions: If the load impedance is equal to the surge generator source impedance, the most energy that can be delivered is one-half of the energy stored in the network. If the load impedance is different, the delivered energy will be less. Therefore, energy delivered IS dependant on the load impedance, but all the impedances involved on the ac mains are complex and are different for every AC line, coupler and EUT. (You can do some simple calculations using resistors in place of the EUT's and assume the generator source is purely resistive and you'll see how the energy fluctuates as the load impedances change.) Does the network always fully discharge? -- The answer is yes, but the hard part is determining where the charge goes -- some energy is used up in the process of forming the waveform (shut resistors internal to the network), some is dissipated in the coupling network (very little), and some goes to the EUT(s). If the EUT impedance is very high -- no energy is dissipated in the EUT; if it is very low, most of the available energy will be dissipated in the EUT. When a discharge occurs, the energy storage capacitor is connected to the surge network which has a resistor connected to ground internally, so if the EUT doesn't take any energy, eventually (milliseconds) all the energy in the capacitor is discharged via the shut network resistance. Just to make sure no surge energy is left (for safety reasons) a relay shorts the network directly to ground a short time after the surge. The test you performed with the Fluke probe and scopes -- first, you need to use good high voltage differential probes to get any meaningful waves when dealing with live power lines and surges. Secondly, you don't say what the EUT impedance looks like -- for example: if both EUT's look like a high impedance compared to the source impedance of the generator (2 ohms), it is likely the voltage waveforms observed won't change when adding additiol EUT's in parallel -- until, of course, you get enough in parallel that the total impedance gets to be much lower. If the impedance of the two EUT's was very low, possible due to the use of varistors or other surge protective devices, the same thing might apply -- it won't matter whether one or both protectors operate, assuming both work, the voltage waves will be the same -- it may be; however, that all the surge current is going through only one of the protectors and the other is getting no current! I'm not familiar with the Fischer probe you mentioned, but Pearson current probes work very well. If you need a model number, let me know. The problem your'e going to have in justifying operating both systems in parallel is that you may not be able to identify a failure -- if both are high impedance and one breaks down, it will prevent the other from seeing any surge voltage and you may not know which one broke down if you're only monitoring surge voltage. If the EUTs are low impedance (with protectors or for some other reason), it is unlikely they will share currents equally, but you won't know until you can make some surge current measurements to make sure. When the behavior of an EUT when hit with a surge is unknown, it is impossible to state that testing two EUT'S in parallel is justified. Only after understanding how each EUT will behave with the surge, will it be possible to determine how they will behave in parallel.. Good luck... If you have any other questions, please give me a call or email -- Mike Hopkins mhopk...@keytek.com or 1-800-753-9835. Mike Hopkins -Original Message- From: Dale Albright [SMTP:dale.albri...@flextronics.com] Sent: Thursday, May 04, 2000 5:04 PM To: wo...@sensormatic.com; emc-p...@ieee.org Subject: RE: Surge Richard, This was our intuitive thought too. However, I do not fully understand the discharge network and do not know, for instance, if the total joules delivered to the coupler is independent of load or impedance. Does the network always fully discharge? Today we spent some time to capture it. The following test was run on the AC: One EUT was connected to the coupling/decoupling network. A digital scope and fast Fluke probe was used to capture the voltage waveform at the input of the EUT. The data was plotted. A second EUT was added in parallel to the coupling/decoupling network. The test was re-run (no moving
RE: EN61326-1 Harmonics
The standards have general applicability; however, the push by the European Power Industry for this standard has been to target switching power supplies as the culprit. Since most ITE use switching power supplies.. According the the scope, both 3-2 and 3-3 apply to virtually all electronic products. Mike Hopkins mhopk...@keytek.com -Original Message- From: Barry Ma [SMTP:barry...@altavista.com] Sent: Tuesday, March 28, 2000 12:40 PM To: chr...@gnlp.com Cc: bkundew...@qtm.net; nprov...@foxboro.com; emc-p...@ieee.org Subject: RE: EN61326-1 Harmonics Hi Chris, Would you please prove that two product family standards 3-2 and 3-3 are only applicable to ITE? Thanks. Barry Ma b...@anritsu.com -- On Tue, 28 March 2000, Maxwell, Chris wrote: . My understanding of the scope of EN 61000-3-2 and EN 61000-3-3 is that it is targeting Information Technology Equipment (ITE). Much of the equipment under EN 61326-1 is not ITE. . For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Lightning Surge Equipment
Bellcore 4.5.9 Intrabuilding lightning calls for testing with 2/10us waves, but as David says, allows for the use of resistor networks added on to a 1.2/50us generator. 2/10 generators for both 2 and 4 wire applications are available for roughly the same price David paid for the Schaffner unit, plus they can be expanded to perform the other Bellcore tests as well. The KeyTek generator mentioned is much less expensive but then you need to build the resistor networks to meet the spec -- You may find it difficult to get the power resistors required: they need to be non-inductive and capable of handling both the voltage (1500V) plus the 100A surge currents. Let me know if you need help there. Mike Hopkins KeyTek -Original Message- From: David Spencer [SMTP:dspen...@oresis.com] Sent: Thursday, March 23, 2000 11:16 AM To: 'n...@world.std.com'; 'EMC PSTC' Subject: RE: Lightning Surge Equipment Joe, If you are only going to do intrabuilding, you can get away with just about anything capable of the 1.2/50uSec wave form (see the provision in the GR for using this waveshape with series resistors). I am just now setting up a lab here and decided to go with Schaffner NSG2050, because it would be an easy module addition should we decide to do outside plant in the future. With the CDN, mainframe, module and 1089 box it was ~34K. Again, if you only want intrabuilding, Keytec makes a product called the CE master for about 17K that will do the waveshape. Keep in touch off line and I will let you know how it all works out once I have played with it (oops, I mean, executed some test plans ;) for a while. Dave Spencer Compliance Engineer Oresis Communications -Original Message- From: Joe Finlayson [mailto:jfinlay...@telica.com] Sent: Thursday, March 23, 2000 6:16 AM To: 'NEBS Newsgroup'; 'EMC PSTC' Subject: Lightning Surge Equipment I am trying to gather information on equipment capable of performing, at minimum, the lightning tests of Bellcore GR-1089-CORE 4.5.9, Intrabuilding Lightning Surge. I am specifically interested in opinions of different equipment, cost and extent of functionality (is there a cost savings for equipment whose functionality is limited to this test?). Any input on used equipment would also be helpful. I am initially interested in pre-test if that makes a difference. Any input would be greatly appreciated. Thx, Joe * ... Joe Finlayson Manager, Compliance Engineering Telica, Inc. 734 Forest Street, Bldg. G, Suite 100 Marlboro, MA 01752 Tel: (508) 480-0909 x212 Fax: (508) 480-0922 Email:jfinlay...@telica.com Web: www.telica.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Split or Not to Split?
Thought this was over by now;;; but since it continues, my vote is NO split. Mike Hopkins mhopk...@keytek.com -Original Message- From: Mark Hassebrock [SMTP:mhass...@qualcomm.com] Sent: Friday, March 17, 2000 3:46 PM To: emc-p...@majordomo.ieee.org Subject: Split or Not to Split? Greetings All, I feel EMC and Safety are joined at the hip so I vote NO Split. Although some companies are fortunate to have dedicated people, I suspect there are many more of us that are required to wear multiple hats. In my humble opinion, the real issue is the shear volume of mailings each day! It's not practical to go through the dozens of postings each day. Unfortunately when I do, I observe many where can I get this standard? or endless threads on Y2K, etc. Let's all commit to doing our homework before posting. My thanks to those who graciously answer questions and provide valuable insights. +++ Mark HassebrockPh. Work: 1-303-247-5005 Regulatory EngineerFax:1-303-247-5116 Qualcomm, Inc.E-mail:mhass...@qualcomm.com Boulder, CO +++ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Surge Testing per EN 55024/EN61000-4-5
As long as there is no other path to ground, a line to line test would be all thats required, but keep in mind, if you have other I/O, telecom, control lines, or anything else coming out of that plastic box, you then have a potential path back to ground, and in fact, will likely have REAL ground connections. For example, many television sets have two wire power plugs, are in plastic cases, but if you have cable tv, the odds are that coax cable is grounded. Same thing applies if there is a telecom line involved -- very likely one of the telecom lines is ground. .. Mike Hopkins mhopk...@keytek.com -Original Message- From: Jim Hulbert [SMTP:hulbe...@pb.com] Sent: Wednesday, March 01, 2000 10:32 AM To: emc-p...@ieee.org Subject: Surge Testing per EN 55024/EN61000-4-5 Colleagues, EN 55024 calls for surge pulses to be applied line-to-line and line-to-earth on the AC mains port and line-to-ground on signal and telecommunications ports that connect directly to outdoor cables. However, if my EUT is encased in plastic covers and has no direct earth ground connection (class 2 power supply), is the line-to-line test on the AC mains the only surge test that I need to apply? It seems to me that performing a line-to-earth test on either the AC mains port or on signal/telecommunications ports is not warranted since the basic standard EN 61000-4-5 does not specify placing the EUT over a reference ground plane. With no reference ground plane and no direct ground connection how can a test be applied with respect to ground? Jim Hulbert Pitney Bowes - This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list adminstrators: Jim Bacher: jim_bac...@mail.monarch.com, or Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN61000-4-11
You can't really use an AC power source for this requirement. The way its done is with a tap switched transformer (KeyTek) or via a switch between two or more variacs or other fixed ac sources. Mike Hopkins KeyTek -Original Message- From: fwhitfi...@rheintech.com [SMTP:fwhitfi...@rheintech.com] Sent: Monday, January 24, 2000 4:11 PM To: emc-p...@ieee.org Cc: bclav...@rheintech.com Subject: EN61000-4-11 EN 61000-4-11 states that the rise/fall time for a test generator used to perform a voltage abnormalities test (i.e. dips, variations etc should be between 1 and 5 microseconds.) Does anyone know of a generator that meets this criterion? I have come across a few but they typically cannot be programmed to work with rise/fall times less than 0.1 milliseconds(i.e. 100 microseconds). Thanks for your usual co-operation. John F. Whitfield - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EN 61000-4-2
IEC 1000-4-2:1995 Page 29, section 8.3.1 The test shall be performed with single discharges. On preselected points at least ten single discharges (in the most sensitive polarity) shall be applied. Of course, you may have a customer who will insist on additional testing, but 10 shots at each of the designated discharge points is the minimum. Mike Hopkins -Original Message- From: kim.boll.jen...@lasat.com [SMTP:kim.boll.jen...@lasat.com] Sent: Monday, January 17, 2000 5:41 AM To: emc-p...@ieee.org Subject: EN 61000-4-2 Dear all I'm writing on a internal testprocedure for our products, and have now come to EN 61000-4-2 ESD. What confuse me is that the standard (as I read it) only refere to 10 discharges at each point (and each polarity), but I have been told from several different persons that the right number is 50 at each points (but without any reference to any standard). Do anynoe know what the right number is and where I can find it Best regards, Mr. Kim Boll Jensen i-data international Denmark - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: transient suppression
Keep in mind rise time (really - turn on time) doesn't mean much on the AC mains. Most specs assume the measurement is made right at the body of the device, so even short wires will add enough inductance for a fast wave to make the arguement moot. -Original Message- From: Dan Kwok [SMTP:dk...@intetron.com] Sent: Tuesday, January 11, 2000 11:09 PM To: Ken Javor; EMC-PSTC Group Subject: Re: transient suppression Ken Javor wrote: When choosing transient suppression for power line input to equipment, what are the choices (MOVs, silicon TVS, glass discharge tubes, others) and what are the trade-offs? Thank you. Hello Ken, Here are some typical device types I've come across for transient suppression: Varistors (MOVs): Voltage Range 35 - 1400 V Max. Current 50 - 100 A Response Time 1 nsec Gas Discharge Tubes: Voltage range 75 - 10,000 V Max. Current 1000+ A Response Time 1000 nsec Zener or Avalanche Diodes (lower voltage DC, Signal) Voltage Range 5 - 200 V Max. Current 1.5 - 10 A Response Time 1 nsec Each device type has its own set of characteristics like polarity of operation and failure mode. You may also need to consider the shunt capacitance which can vary from 1pF to 100 nF depending on the device type. Which type is best? It all depends on the specific application, transient signal and the susceptibility of the equipment you are protecting. It usually boils down to a trade-off between speed, size, transient handling capacity and cost. Hope that helps. Regards, Dan -- = Dan KwokVancouver, BC, Canada Intetron Consulting, Inc. Telephone 604.432.9874 Email dk...@intetron.com FREE EMC Tips @ our website http://www.intetron.com; = - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: transient suppression
Clamps are necessary if you don't want the AC mains shorted to ground for each transient event. MOV's are the most commonly used suppressors for the AC line. Use MOV's rated at higher than the peak AC voltage expected on the mains. Clamping voltages are typically in the 300 to 500V region; however, they will handle a good deal of energy in a single shot. Some manufacturers use strings of silicon clamping devices, but thier charateristics after packaging, lead lenghts, etc... end up being very much like MOV's. The big disadvantage is they are rated for a maximum amount of current and if you go over the number even slightly, they'll blow. Avalanche devices in series with a resistor or clamp are sometimes used, but not as effective as a simple MOV. Mike Hopkins KeyTek -Original Message- From: Robert Macy [SMTP:m...@california.com] Sent: Tuesday, January 11, 2000 7:26 PM To: Ken Javor; emc-p...@majordomo.ieee.org Subject: Re: transient suppression Ken, Rule of thumb which hopefully is accurate: MOV's have a discrete lifetime (like 10 cycles at full rating) before they're gone. In order of joules absorbed versus package size: Glass tubes, MOV's, silicon (from huskiest to weakest) For turn on time: silicon, MOV's, glass tubes (from fastest to slowest) The glass tubes absolutely take a discrete amount of time before they're on The voltage across the MOV's can really go very high as they're coming on - like 3 times they're rating voltage. The overshoot depends upon the rise time of the incoming. Performance in the system depends a great deal upon the lead length, layout etc for real effectiveness. - Robert - -Original Message- From: Ken Javor ken.ja...@emccompliance.com To: emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Date: Tuesday, January 11, 2000 3:32 PM Subject: transient suppression When choosing transient suppression for power line input to equipment, what are the choices (MOVs, silicon TVS, glass discharge tubes, others) and what are the trade-offs? Thank you. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Tiger Tail for 27 MHz?
That will work, but the electrical length of the tail will change due to the inductance of the coil you're winding... This method has been used to produce shorter antenna elements in the HF (3-30MHz) region with some success; however, shorter antenna elements generally also mean loss rather than gain.. Mike Hopkins -Original Message- From: Lacey,Scott [SMTP:sla...@foxboro.com] Sent: Tuesday, January 11, 2000 8:33 AM To: 'emc-p...@ieee.org' Cc: 'sla...@foxboro.com' Subject: Tiger Tail for 27 MHz? Fellow Listmembers, I have a question regarding tiger tails used to improve transmission characterisics of a hand-held transmitter (HHT). The HHT is basically a dipole, with the chassis as the bottom element. The tiger tail is a quarter-wave length of wire that connects to the shell of the coaxial connector and is allowed to hang downwards, effectively increasing the electrical length of the chassis. They are commonly used with higher frequency HHT's where a quarter wavelength is relatively short compared to a standing man. I want to fabricate one for use with a 27 MHz (CB) HHT. I need a length of wire more than nine feet long. My question is this: If I wind the nine feet of wire spirally around a length of polypropylene rope, will it still work properly? Also, should I use Litz wire? Thanks in advance for any help. Scott Lacey - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Radiation levels.
Seems to me it can be almost anything -- AM broadcast stations in the US range from a few hundred watts to 10kW could be much higher (and probably is) in some contries like Mexico.. I've been out of this business for a while, but I remember FM and TV broadcast radiation being listed as ERP (effective radiated power) -- figures I remember in the hundreds of kW. Many orders of magnitude removed from GSM or other cell phones, which I think are below one watt (someone can correct me, but .3W sticks in my mind for US analog phones, but I have no idea about European power levels.) Hope this is useful. Mike Hopkins mhopk...@keytek.com -Original Message- From: David Monreal [SMTP:dmonr...@advancedshielding.com] Sent: Tuesday, January 11, 2000 5:15 AM To: emc-p...@majordomo.ieee.org Subject: Radiation levels. Hi all! Could anyone tell me the radiation levels (V/m) generated by broadcast antennae? (Radio and TV). I also need the radiation levels for any other emmitig devices, machinery, GSM antennae, etc. The more information the better. Thanks a lot :-) David - The V/m guy File: David Monreal.vcf - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Y3K
According to IEEE's standard dictionary of Electrical and Electronics Terms, there are two meanings for k (lower case) and two for K (upper case): K: cathode (vacuum tube) K: kelvin k: kilo k: Bolzmann's constant Note: They do NOT list M (caps) as Mega, but do list m (lower case) as milli. The 1998 EMC Encyclopedia shows M = mega and m = milli. Mike Hopkins KeyTek -Original Message- From: Gary McInturff [SMTP:gmcintu...@telect.com] Sent: Thursday, January 06, 2000 5:50 PM To: 'Egon H. Varju'; EMC-PSTC Subject: RE: Y3K Oh my last birthday my children wanted to know if I was really, really sad when the Dinosaur's all died - heavy sigh! Anyway - M is for Mega or 1,000,000 and K for Kilo or 1,000 But I'm sorta betting you're getting tired of hearing that. Gary -Original Message- From: Egon H. Varju [mailto:e...@varju.bc.ca] Sent: Thursday, January 06, 2000 9:17 AM To: EMC-PSTC Subject:Re: Y3K Roger, way back in the days of the caveman, 1M ohms = 1000 ohms. Guess going metric changed everything. Strange ... During my dinosaur hunting days, 1M ohm used to be = 1 000 000 ohms. Maybe we grew up in parallel universes ... Egon :-) __ Egon H. Varju, PEng E.H. Varju Associates Ltd. North Vancouver, Canada Tel: 1 604 985 5710 HAVE MODEM Fax: 1 604 273 5815 WILL TRAVEL E-mail: e...@varju.bc.ca eva...@compuserve.com egon.va...@csa-international.org __ - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Magnetic field monitors
Our customers have asked us to supply a meter which can be used to monitor/measure magnetic fields in Amps/meter for setting up tests IAW IEC 61000-4-8. We've been offering a meter made in the U.S that reads in Gauss (seems okay for U.S. customers), but some customers in the far east are insisting on meter that reads in international units. We suggested a meter made by a German company that reads in Tesla, but they said, No, we need international units of Amps/meter. Anyone out there make a meter that reads in Amps/meter \??? We've not been able to locate one. Thanks Best Regards Michael Hopkins mhopk...@keytek.com Tel: 1-978-275-0805 ext. 134 Fax: 1-978-275-0850 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: IEC 61000-4-28
This is one of many Basic EMC standards that exist, but are not required for complinace by Product or Product Family standards. All of these other basic standards have been requested by some part of industry (that's how they get started), but that doesn't mean they are applicable in any broad sense. If product committees want to use these for compliance, they are free to do so, but the IEC guidelines in 1000-4-1 make it clear which have general applicability and which do not. This one does NOT. Mike Hopkins mhopk...@keytek.com -Original Message- From: Martin Rowe (TMW) [SMTP:m.r...@ieee.org] Sent: Monday, November 29, 1999 9:57 AM To: emc-p...@majordomo.ieee.org Subject: IEC 61000-4-28 I received the following announcement from IEC: IEC 61000-4-28 (1999-11) - Electromagnetic compatibility (EMC) - Part 4-28: Testing and measurement techniques - Variation of power frequency, immunity test Establishes a reference for evaluating the immunity of electric and electronic equipment when subjected to variations of the power frequency. Only conducted phenomena are considered, including immunity tests for equipment connected to public and industrial networks. ICS code: 33.100.20 - SC 77A - 27 pp. - CHF 55.00 Does anyone care about IEC standards? By that, I mean does anyone make an effort to comply with a standard that's not published in the OJ and therefore is not required for CE marking? Might individual countries require compliance? Thanks, /\ | Martin Rowe | / \ | Senior Technical Editor | /\ /\ | Test Measurement World | / \/ \/\ | voice 617-558-4426 |/\ /\ / \/ | fax 617-558-4470 | \/ \/ | e-mail m.r...@ieee.org | \ / | http://www.tmworld.com |\/ - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Power Amps for Immunity Testing
Try Kalmus -- Leo Smale at leosm...@seanet.com or 11807 North Creek Parkway S. Suite 109 Bothell, WA 98011 Tel: 1-800-344-3341 1-206-485-9000 Fax: 1-206-486-9657 Mike Hopkins -Original Message- From: dber...@wlgore.com [SMTP:dber...@wlgore.com] Sent: Friday, November 19, 1999 11:59 AM To: emc-p...@majordomo.ieee.org Subject: Power Amps for Immunity Testing List-friends, I am trying to perform some in-house immunity troubleshooting, and I want to generate 10V/m fields up to several GHz. What power amps would you recommend, and does anyone know of a good source to rent them? Dana J. Bergey W. L. Gore Associates, Inc. dber...@wlgore.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Doubt on household equipment interference
Sounds like a definate maybe... Mike Hopkins -Original Message- From: Muriel Bittencourt de Liz [SMTP:mur...@grucad.ufsc.br] Sent: Wednesday, September 01, 1999 3:55 PM To: Lista de EMC da IEEE Subject: Doubt on household equipment interference Dear Members I'd like to solve a doubt.. suppose the following: I have an electrical installation in a house. The feeding is with three-phase and one neutral conductors. If I connect a TV and a blender in the same phase, the blender generates interference (lines) in the TV screen. If I connect the TV in one phase, and the blender in another, the TV will have interference??? The neutral conductor is the same for all (of course!) Seems very plain, but I'd like to know... :) Thanks in advance Muriel -- == Muriel Bittencourt de Liz GRUCAD - Conception Analysis of Electromagnetic Devices Group Federal University of Santa Catarina PO Box: 476 ZIP: 88040-900 - Florianópolis - SC - BRAZIL Phone: +55.48.331.9649 - Fax: +55.48.234.3790 e-mail: mur...@grucad.ufsc.br ICQ#: 9089332 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Concrete as an insulator??? -- and now FCC/FAA
If I'm not mistaken, there IS an FAA regulation prohibiting the use of cell phones in airplanes -- I have the regs at home and will look it up. Mike Hopkins mhopk...@keytek.com -Original Message- From: miksher...@aol.com [SMTP:miksher...@aol.com] Sent: Tuesday, August 24, 1999 11:13 AM To: gmcintu...@packetengines.com; ed.pr...@cubic.com; emc-p...@ieee.org Subject: Re: Concrete as an insulator??? In a message dated 8/23/1999 5:05:26 PM Central Daylight Time, gmcintu...@packetengines.com writes: Does anybody know why the FCC - not the FAA has regulations against using a cell phone in a private airplane. It is a little more obvious for a commercial airplane that use the fuselage as a return path from various equipment bays but private plans aren't wire that way - I don't think. There was a comment made that it interferes with the Cell system in some manner, any clues? Stated reason I've always heard, and which makes sense to me: one triggers multiple cells once one is airborne, which messes up a system that is designed to hand off a call cell to cell, based on signal strength and an assumption that the phone is on the ground. Mike Sherman FSI International - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: re: EN50082-1:1997 EN55024
I'm not sure I'm the most appropriate person to answer, but here's my opinion. Doug Smith at Auspex (also a member of this ieee group) is probably the best qualified to talk about ESD and other noise phenomena: Back in the mid '80's when we were demonstrating ESD simulators (air discharge only), we saw a lot of cases where EUT's survived higer voltages -- 8 to 10kV, but failed when tested at a few kV. With the scopes at the time, we could see faster rise times at the lower voltages (about 2-5kV), slower risetimes at intermediate voltages (5-10kV) and faster risetimes again at the higher voltages (10kV). We attributed these low voltage failures to the faster risetimes with air discharges below about 5kV. I I think this scenereo is still valid, and we see risetimes of a few hundred pico seconds below about 3kV. Risetimes do get to be slower at higher voltages. David Pommerenke at HP has done a lot of recent work to characterize human ESD with modern scopes and high bandwidth instrumentation. With contact mode testing, I'm not sure the same argument applies. With a simulator that has very clean risetimes, the risetime is held constant (IEC is .7 to 1ns) with voltage. di/dt in fact increases with voltage, which would be evidence for more failures at higher voltages, but this doesn't seem to be the case in practice. Nevertheless, people keep coming up with cases where lower voltages cause failures where higher voltages are okay. Some possibilities for the problem with contact mode: 1. Some simulator have a considerable amount of ringing on the rising edge of the current waveform -- ESD Association work under WG14 -- also papers published at past ESD Symposiums by HP and others. This ringing could be inconsistant with voltage and be a significant contributor to failures. 2. Breakdowns inside the EUT in air across very small gaps could produce risetimes well under 400ps. 3. Other ideas In any case, it is still felt by members of IEC TC77B WG9 (now in the process of completely re-evaluating IEC 61000-4-2) that testing at lower voltages is required to insure a product is, in fact, immune to ESD. This requirement will likely continue into any future version of the IEC standard. The latest draft of ANSI/IEEE C63.16- includes statements recommending testing begin at the lowest voltage and progress to higher voltages -- 1kV intervals for contact mode and 2kV intervals for air discharge. It's clear these requirements will go forward -- there's just too much evidence for the existance of the phenomena, even though the reasons aren't always clearly understood for a specific EUT. Mike Hopkins mhopk...@keytek.com -Original Message- From: b...@anritsu.com [SMTP:b...@anritsu.com] Sent: Thursday, August 19, 1999 6:56 PM To: Mike Hopkins Subject: fwd: re: EN50082-1:1997 EN55024 Mike, You are the most appropriate person to answer the question that why DUT could fail at lower ESD voltage sometimes. Can you post your answer directly to the emc-pstc group? Thank you. Barry Ma b...@anritsu.com -- Original Text -- From: Leslie Bai leslie_...@yahoo.com, on 8/19/99 3:00 PM: To: Bailin Ma@MMDILAB@ACUS Barry, I agree with you but just wondering why DUT got larger current at lower ESD voltage. BTW, I called Anritsu early this week requesting for a demonstration of Site Master but just couldn't get any reply yet. Rgds, Leslie --- b...@anritsu.com wrote: Jim, You have been doing right thing. Those who directly go to the highest ESD voltage level may thought if DUT can pass the highest level it will certainly pass lower level. As a matter of fact, DUT could possibly fail at lower level and pass at higher level. Because DUT got larger current at lower ESD voltage. ... Barry Ma b...@anritsu.com -- Original Text -- From: Jim Hulbert hulbe...@pb.com, on 8/19/99 11:34 AM: Immunity test standards EN50082-1:1997 and EN 55024 call out the basic standards EN61000-4-2 and EN61000-4-5 for ESD and Surge. EN61000-4-2, Section 5 starts out The preferential range of test levels for the ESD test is given in table 1. Testing shall also be satisfied at the lower levels given in table 1. EN61000-4-5, Section 5 contains similar wording. This is how we perform our compliance tests. We start at the lowest test voltage levels from the respective tables and step up to the test levels called out in EN50082-1/ EN55024 (or higher, depending on our own in-house product spec.) However, I have noticed that some test labs go straight to the levels called out in EN 50082-1/EN55024 and skip testing at the lower levels. I believe this approach is incorrect because it does not conform to the requirements of the basic standard and is simply not a complete test. As explained in EN61000-4-5, the non-linear current
RE: GTEM cell
Careful -- for FCC emissions it's allowed only if correlation with an OATS is achieved for a given product. For the next product, correlation may have to be re-done. For immunity to EN's, it isn't so clear. IEC 61000-4-3 is written as if any type of TEM cell is NON compliant, but a draft annex is now being circulated that would allow TEM cells, but ONLY if a TEM wave can be demonstrated throughout the frequency range being used (3-axis measurement, undesired vectors 6 db down). For emissions to EN's, TEM cells are not allowed for compliance testing. Mike Hopkins mhopk...@keytek.com -Original Message- From: Leslie Bai [SMTP:leslie_...@yahoo.com] Sent: Wednesday, July 07, 1999 11:25 AM To: Qu Pingyu; 'emc' Subject: Re: GTEM cell Pingyu, I guess GTEM cell is a good choice for your case. Pls refer to IEC61000-4-3 (for immunity) and ANSI C63.4 (for emission), GTEM cell is not only recognized for pre-compliance test but also can be used for compliance test as long as some correlation can be achieved. We did correlation through both modeling, simulation using FDTD and actual testing to verify the results. We are using GTEM cell for many different kinds of products compliance test and PCB trouble-shooting. It is pretty good. But you have to pay attention to the uniformity volume of GTEM cell, it's a bit tricky, especially the cabling of EUT may affect the result, thus, during the correction, a harness is supposed to be used to simulate the EUT cabling. Hope it helps. Leslie --- Qu Pingyu pin...@ime.org.sg wrote: Hello, Everyone: I have some questions regarding the GTEM cell. Here in our Institute we are considering setting up some EMC measurement capability for precompliance testing. The EUTs we are dealing with are not very large, probably not larger than a desktop PC. Do you think that GTEM cell is a good choice ? Do many of you use GTEM as a precompliance testing facility ? Your comments are highly appreciated. Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Position open with KeyTek
Having seen numerous postings relating to job openings in EMC, I trust the following is not out of line: Electronic Design Engineer Position Senior electrical/electronic engineer with analog design background to work on design of KeyTek's pulsed-EMI (surge, EFT) and ESD test systems. The ideal candidate would have experience with high-frequency, high voltage, and high current design, and have worked with surge or other pulsed-EMI test equipment. More general relevant design experience would be a background in power electronics, power supply design, or test and measurement instrumentation. Knowledge of the various national and international standards for safety and electromagnetic interference is desirable. This is a senior-level position, and the individual should be degreed with a proven record in product design. In this small company environment there is a great deal of room for professional growth for an appropriate energetic individual. Best Regards Michael Hopkins mhopk...@keytek.com Tel: 1-978-275-0805 ext. 134 Fax: 1-978-275-0850 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Transmission Line Theory
Your first assumption is incorrect: the transmission line only operates as a transmission line if it has a source at one end and a load at the other end. If the source, line and load are all the same impedance, maximum energy is transferred to the load. Assuming all impedances are matched, the load is near the source and some unknown length of line is also connected to the load, that line could act in a number of ways: depending on its length, the frequency of the applied signal and whether or not the line is open or shorted, it would act as a series or parallel LC circuit connected to the load. If this extra line is a single line and not paired with a return, it will likely operate as an antenna. If that line were the same impedance as the load, half the energy from the source would go to the antenna and half to the load... Mike Hopkins mhopk...@keytek.com -Original Message- From: Allen Tudor [SMTP:allen_tu...@pairgain.com] Sent: Wednesday, May 12, 1999 5:31 PM To: emc-p...@ieee.org Subject: Transmission Line Theory Greetings group, I am trying to draw a parallel between transmission line theory and radiated emissions. From what I understand, a transmission line can be terminated at the source or the load with an impedance that equals the characteristic impedance of the transmission line itself. With this in mind, consider this scenario. A printed circuit card drives a clock signal down a trace on a backplane. The length of the backplane trace is long enough to be considered a transmission line. The driver on the printed circuit card is located within ½ inch of the edge connector (mating with the backplane) and is terminated with an impedance equal to the characteristic impedance of the backplane trace. However, the backplane trace is open ended (there is nothing connected to the end of the trace). Transmission line theory says the signal integrity will be maintained in this case. Now for the questions: (1) How much, if any, of the energy will be radiated into free space when it gets to the end of the open transmission line? To me, this looks like a monopole antenna. I don't have a very good understanding of antenna theory, so this could very well be an invalid assumption. (2) If radiation does take place as stated above in question (1), which is better for reducing the radiation, termination at the source or termination at the load of the transmission line, or does it matter? (3) If the characteristic impedance of the trace on the printed circuit card differs from the characteristic impedance of the trace on the backplane, how is this handled? Is a termination needed at each end in this case? I look forward to your responses. Thanks. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: RE: ESD in Power Station
Quite frankly, I don't think higher ESD voltages in power sub-stations is justified from the standpoint of the voltage threat. Modern sub-station control rooms are much like office environments and older stations are concrete floors with wooden or metal furnature (and not much of it!). Perhaps the higher levels are required NOT because ESD is more of a problem, but because a failure could be more catastrophic than in your average office. Improper switching could cause realitively large scale outages and possible damage to the system. Mike Hopkins mhopk...@keytek.com -Original Message- From: b...@namg.us.anritsu.com [SMTP:b...@namg.us.anritsu.com] Sent: Thursday, April 01, 1999 11:24 AM To: emc-p...@ieee.org Subject: fwd: RE: ESD in Power Station If instruments in power stations need more stringent ESD standard, what about instruments in radio, TV, and cell stations? Did anybody have similar extraordinary feelings there? Barry Ma - Original Text From: Mike Hopkins mhopk...@keytek.com, on 4/1/99 7:35 AM: To: Cc: Didn't mean to mislead -- my comment about feeling the electricity in the air is just that, a subjective feeling Maybe ozone played a part; I was too young and inexperianced to recognize it if that were the case. More of a sensation -- I do remember the 60Hz hum coming from all directions as soon as you entered the sub-station.. Mike Hopkins -Original Message- From: b...@namg.us.anritsu.com [SMTP:b...@namg.us.anritsu.com] Sent: Wednesday, March 31, 1999 5:36 PM To: emc-p...@ieee.org Subject:ESD in Power Station Hi, Please allow me to pose two questions. (1) What did Mike Hopkins and Scott Douglas really feel and smell about electricity in the air when these two boys went to electricity stations with their fathers? My guess -- that's air ions and ozone, which are easily produced in a strong AC EM field. If this is true, can we say: The more ions in the air, the easier ESD would happen? (2) The eddy current on moving conductors in a strong H-field would produce eddy resistance in moving direction. That's a good explanation for slow watch on the spot. But my question: How come an AC (not DC) H-field left the moving iron with residue magnetization which causes the watch continuing slow after leaving the station? Barry Ma From: Robert Macy m...@california.com, on 3/31/99 12:33 PM: IMHO the magnetic fields go right through the watchcase and either disrupt what's going on or can even magnetize the parts. Either way, the parts are like stuck together and the watch won't run well. Also, my father could never wear a watch, a great gift watch always would stop. The same watch given to my brother, lost ten minutes a day. So when I got the watch I was happy when it gained a few seconds a month and lasted for over ten years. Go figure. --- From: Mike Hopkins mhopk...@keytek.com, on 3/30/99 9:48 PM: Very interesting -- my father also worked for what was then New England Power and was a substation operator in Tewksbury, MA -- he also went to other smaller sub-stations to switch lines in or out for maintenance or to clear trouble problems and I have similar recollections about the electricity in the air -- you really could feel it! An interesting side note - he could never wear a watch of any kind -- they would either run in their own time zones or not work for long at all -- he attributed this to the surrounding electric fields, but I've never figured out how that would affect a mechanical watch! As for ESD (human ESD) as opposed to AC electric or magnetic fields, the levels of 8kV and 15kV (contact/air) are on the high side. Discharges of a few kV happen all the time without us even knowing it; discharges that we feel on a dry day are typically in the 5 to 10kV range, but a 15kV discharge from the end of your finger is something you'd remember! Even 10kV is pretty uncomfortable.. Hope this is helpful, but I doubt it would influence the people who wrote the standard... --- From: Scott Douglas s_doug...@ecrm.com, on 3/30/99 9:43 AM: My father worked for the electric utility for many years. There were times he could take me with him to check on how a substation was working after some maintenance or upgrade was performed. From direct experience I can tell you that when you enter the substation building, you can quite often feel and smell the electricity in the air. The electrostatic fields that build up in these environments can be substantial. Yes, everything inside is well grounded, but when you have thousands of volts running around big copper bus bars, switching systems
RE: I/O Surge
The problem, of course, is that your'e trying to filter surge signals (the low frequency components from a 1.2/50us impulse get down to pretty low frequencies) which get close to the frequencies you want to pass. It's extremely difficult to make filters with sharp cut-offs that will handle 6kV impulses and 3000A surge currents (the extreme, but many of the generators are capable of putting out these energies so you need to design for the operator who sets it up that way.) The higher the frequency you want to pass, the more difficult the design. The other problem is you need enough back impedance to support the desired surge voltage wave. The higher that impedance becomes for the surge wave, the higher it is for the signals you want to pass as well. If the source impedance is 42 ohms (per IEC 1000-4-5), the impedance to the surge wave looking at the coupler input must be much greater than 42 ohms (if it's only 42 ohms for the surge voltage frequencies, you'll only get 50% of the desired surge voltage -- ohms law). Anyway, it isn't simple. If someone does have a good way of increasing the signal frequency capability of the CDN's, we'd like to hear about it. Mike Hopkins mhopk...@keytek.com -Original Message- From: WOODS, RICHARD [SMTP:wo...@sensormatic.com] Sent: Wednesday, March 31, 1999 10:05 AM To: 'emc-pstc'; 't...@world.std.com' Subject: I/O Surge EN50130-4, Immunity for alarm systems, requires that signal lines be surge tested per EN6100-4-5 using the coupler/decoupler network in figure 12 for balanced signal pairs. The equipment available on the market has a bandpass rating of 100 kHz, and the standard does not specify the type of circuits to be used for very high data rates. My question to the community is what type of network are you using for Apple Talk (circa 230 KHz) and similar high speed circuits? - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: ESD in Power Station
Didn't mean to mislead -- my comment about feeling the electricity in the air is just that, a subjective feeling Maybe ozone played a part; I was too young and inexperianced to recognize it if that were the case. More of a sensation -- I do remember the 60Hz hum coming from all directions as soon as you entered the sub-station.. Mike Hopkins -Original Message- From: b...@namg.us.anritsu.com [SMTP:b...@namg.us.anritsu.com] Sent: Wednesday, March 31, 1999 5:36 PM To: emc-p...@ieee.org Subject: ESD in Power Station Hi, Please allow me to pose two questions. (1) What did Mike Hopkins and Scott Douglas really feel and smell about electricity in the air when these two boys went to electricity stations with their fathers? My guess -- that's air ions and ozone, which are easily produced in a strong AC EM field. If this is true, can we say: The more ions in the air, the easier ESD would happen? (2) The eddy current on moving conductors in a strong H-field would produce eddy resistance in moving direction. That's a good explanation for slow watch on the spot. But my question: How come an AC (not DC) H-field left the moving iron with residue magnetization which causes the watch continuing slow after leaving the station? Barry Ma From: Robert Macy m...@california.com, on 3/31/99 12:33 PM: IMHO the magnetic fields go right through the watchcase and either disrupt what's going on or can even magnetize the parts. Either way, the parts are like stuck together and the watch won't run well. Also, my father could never wear a watch, a great gift watch always would stop. The same watch given to my brother, lost ten minutes a day. So when I got the watch I was happy when it gained a few seconds a month and lasted for over ten years. Go figure. --- From: Mike Hopkins mhopk...@keytek.com, on 3/30/99 9:48 PM: Very interesting -- my father also worked for what was then New England Power and was a substation operator in Tewksbury, MA -- he also went to other smaller sub-stations to switch lines in or out for maintenance or to clear trouble problems and I have similar recollections about the electricity in the air -- you really could feel it! An interesting side note - he could never wear a watch of any kind -- they would either run in their own time zones or not work for long at all -- he attributed this to the surrounding electric fields, but I've never figured out how that would affect a mechanical watch! As for ESD (human ESD) as opposed to AC electric or magnetic fields, the levels of 8kV and 15kV (contact/air) are on the high side. Discharges of a few kV happen all the time without us even knowing it; discharges that we feel on a dry day are typically in the 5 to 10kV range, but a 15kV discharge from the end of your finger is something you'd remember! Even 10kV is pretty uncomfortable.. Hope this is helpful, but I doubt it would influence the people who wrote the standard... --- From: Scott Douglas s_doug...@ecrm.com, on 3/30/99 9:43 AM: My father worked for the electric utility for many years. There were times he could take me with him to check on how a substation was working after some maintenance or upgrade was performed. From direct experience I can tell you that when you enter the substation building, you can quite often feel and smell the electricity in the air. The electrostatic fields that build up in these environments can be substantial. Yes, everything inside is well grounded, but when you have thousands of volts running around big copper bus bars, switching systems, transformers, etc. you hear the hum and feel the electricity in the air. Back then, I thought it was really neat as I did not have the healthy respect that I have since acquired the hard way. One other thought here, would you want your TV going blink just at the end of the local cricket match or the last quarter of the World Cup football game? That could happen if some protective device or overcurrent sensor got zapped and caused a shutdown when there was really no system problem requiring a shutdown. --- From: Peter Poulos pet...@foxboro.com.au, on 3/30/1999 5:54 AM I've recently been shown a standard published by a European group called UNIPEDE titled Automation and Control Apparatus for Generating Stations and Substations - Electromagnetic Compatibility Immunity Requirements - Ref# 23005Ren9523. This standard generally adheres to the same requirements for immunity as the CE-mark standards, however for ESD it requires 8kV contact and 15kV air for HV substation environments. As is usually the case, there's no rationale provided as to why these level where chosen (something that really annoys me about most standards). Does anyone
RE: EMC for automation control - Electricity utilities (UNIPEDE )
Very interesting -- my father also worked for what was then New England Power and was a substation operator in Tewksbury, MA -- he also went to other smaller sub-stations to switch lines in or out for maintence or to clear trouble problems and I have similar recollections about the electricity in the air -- you really could feel it! An interesting side note - he could never wear a watch of any kind -- they would either run in their own time zones or not work for long at all -- he attributed this to the surrounding electric fields, but I've never figured out how that would affect a mechanical watch!. As for ESD (human ESD) as opposed to AC electric or magnetic fields, the levels of 8kV and 15kV (contact/air) are on the high side. Discharges of a few kV happen all the time without us even knowing it; discharges that we feel on a dry day are typically in the 5 to 10kV range, but a 15kV discharge from the end of your finger is something you'd remember! Even 10kV is pretty uncomfortable.. Hope this is helpful, but I doubt it would influence the people who wrote the standard... Mike Hopkins mhopk...@keytek.com -Original Message- From: s_doug...@ecrm.com [SMTP:s_doug...@ecrm.com] Sent: Tuesday, March 30, 1999 10:26 AM To: pet...@foxboro.com.au Cc: emc-p...@majordomo.ieee.org Subject: Re: EMC for automation control - Electricity utilities (UNIPEDE) Peter, My father worked for the electric utility for many years. There were times he could take me with him to check on how a substation was working after some maintenance or upgrade was performed. From direct experience I can tell you that when you enter the substation building, you can quite often feel and smell the electricity in the air. The electrostatic fields that build up in these environments can be substantial. Yes, everything inside is well grounded, but when you have thousands of volts running around big copper bus bars, switching systems, transformers, etc. you hear the hum and feel the electricity in the air. Back then, I thought it was really neat as I did not have the healthy respect that I have since acquired the hard way. One other thought here, would you want your TV going blink just at the end of the local cricket match or the last quarter of the World Cup football game? That could happen if some protective device or overcurrent sensor got zapped and caused a shutdown when there was really no system problem requiring a shutdown. Scott s_doug...@ecrm.com pet...@foxboro.com.au writes: Hi. I've recently been shown a standard published by a European group called UNIPEDE titled Automation and Control Apparatus for Generating Stations and Substations - Electromagnetic Compatibility Immunity Requirements - Ref# 23005Ren9523. This standard generally adheres to the same requirements for immunity as the CE-mark standards, however for ESD it requires 8kV contact and 15kV air for HV substation environments. As is usually the case, there's no rationale provided as to why these levels where chosen (something that really annoys me about most standards). Does anyone have suggestions as to why the authors of the standard would expect worse ESD conditions in a substation than they seem to expect in an air conditioned, carpeted office? (equipment in environments other than HV substations only need meet 6kV contact, 8kV air according to this standard) - Please note: The views, opinions and information expressed and/or contained herein do not necessarily reflect the opinions or views of Foxboro, the organisation/s through which this communication was transmitted nor any other third party, unless explicitly stated so. Peter Poulos (Hardware Design Engineer) Foxboro Australia 42 McKechnie Drive, Eight Mile Plains, QLD, Australia 4113 Tel:+61 (07) 3340 2118 Fax: +61 (07) 3340 2100 E-mail:pet...@foxboro.com.au - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Bellcore GR1089
Be careful -- the lightning tests (surge) are NOTHING like the IEC standards for Europe. The AC line test is the same, but there are several telecom line tests requring 10/1000, 10/360, and 2/10us waveforms at various voltages and currents. Most tests are three terminal tests (tip ring surged simultaneously with respect to ground), but there are also 4-wire tests (two, 3-wire pairs) and 12 pair tests. Additionally there is a 10/250us impulse used for coaxial lines that is HUGE energy... Mike Hopkins mhopk...@keytek.com -Original Message- From: tdonnelly [SMTP:tdonne...@lucent.com] Sent: Wednesday, January 06, 1999 9:11 AM To: w...@skybest.com Cc: emc-pstc Subject: RE: Bellcore GR1089 The standard GR-1089-CORE is available for purchase in electronic media at http://www.bellcore.com/BC.dynjava?BellcoreHomeHomeGeneralHome If you go into the into the Information Superstore and do a keyword search for GR-1089-CORE you get to the following summary: Document Number GR-1089 Issue Number 02 Issue Date Dec 1997 Product Type Industry Requirements And Standards (RS) Replaces TA-NWT-001089 Issue02 Component of FR-2063, FR-440, FR-64 ORDERING INFORMATION ABSTRACT: This Generic Requirements (GR) document contains the Electromagnetic Compatibility (EMC) and electrical safety criteria, that in Bellcore's view, are necessary for equipment to perform safely and reliably in the environment of a Telecommunications Service Provider. Components of this product are: GR-1089-CORE The cost is $350 and they accept the major credit cards. As Gary indicated the EMC testing is significant but it also gets into electrical safety requirements. Also as Gary indicated equipment specified to meet this requirement often have to meet the Bellcore NEBS GR-63-CORE requirements. This standard covers such things as Operation Temperature and Humidity, Altitude, Heat Dissipation, Flame Resistance, Fire testing, Use of fire-resistant Material, Smoke Corrosivity, Equipment Shock, Earthquake, Vibration, Contamination. This standard itself is fairly extensive and if your customer is not asking for it I would not worry about it, but you should be aware of it. GR-63-CORE can be found at the Bellcore Site as well. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Gary McInturff Sent: Tuesday, January 05, 1999 8:00 PM To: 'Fred Waechter'; emc-pstc Subject: RE: Bellcore GR1089 You can get the standard through Bell Labs, Global engineering documents may also have it. Its long and arduous. It extends the FCC limits down to 10 Khz or so and up to 10 GHz, You may be required to do some radiated emissions testing in this range as well as conducted emissions. The where the FCC has limits they are pretty much the same for the 1089 tests. They rise above and below this points, but I haven't got the figures in front of me. They required susceptability requirements for surge, and ESD etc that sort of match the Heavy industrial standards for Europe. There is a heck of lot more to it than this - this is just a ballpark figure. I would certainly recommend that you get at least that standard and spend a grunch of time looking it over before you make a guess at whether the supply will meet or not. I would also ask the client why he wants these tests. If it is going into end use equipment that is going into a telephone company premises the end client may have other questions for you like earthquake protection and fire protection. For the earthquake stuff heavy things like power supplies are at risk - they like to keep moving after the shaker has tried to change directions. You may even have to physically burn the power supply to observe the flame and smoke production during and after the application of flame. Typically requiring flame classifications of 94v0 and better or components with an oxegen index greater than 25 (I think). If it is fixed equipment the flame rating could even go to UL94-5V. So lots to think about. Gary -Original Message- From: Fred Waechter [SMTP:w...@skybest.com] Sent: Tuesday, January 05, 1999 10:01 AM To: emc-pstc Subject:Bellcore GR1089 Hi all, I'm a consultant to a power supply manufacturer on the west coast. They have a potential customer who asked if a particular power supply could meet Bellcore GR1089. Neither the factory or I are familiar with this standard. Does anyone know what it refers to and/or where I can get a copy of this standard? Thanks in advance for your help. -- Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com Phone/FAX: 336-246-5236 - This message is coming from the emc
RE: Signatory for US based Manufacturer
Excellent! Note: this applies to Technical Construction Files and Type Acceptance as well. But on to the third paragraph: Where neither the manufacturer nor his authorized representative is established within the Community, the above obligation to keep the EC declaration of conformity available shall be the responsibility of the person who places the apparatus on the Community market. This paragraph (without any comma's) clearly implies the manufacturer could be outside the EU. If that's true (then back to paragraph 1), a US manufacturer can sign the DofC ! In the 1997 Guidelines on the application of Council Directive 89/336/EEC of 3 May 1989 on the approximation of the laws of the Member States relating to electromagnetic compatibility (whew!!), there are a number of clarifications that refer to the manufacturer and his obligations, including statements that the manufacturer, ... has sole and ultimate responsibility for conformity of this apparatus to the applicable directives..., and is, ... the sole and ultimate responsible person... regarding EMC. There IS one place where your (Tania) comment about comma's is relavent: From the guide mentioned above, section 3. Definitions, in the 4th paragraph under comments is the statement (with comma placed appropriately): If a manufacturer, his authorized representative in the EEA or the importer offers an apparatus covered by the Directive... In this case the manufacturer is not assumed to be in the EU. Enough of that My own opinion is that the manufacturer in any country can sign a Declaration of Conformance, but it must be kept on file in the EU by a representative of the manufacturer or by the importer. Happy Holidays to all That's all the document research time I have this month Mike Hopkins mhopk...@keytek.com -Original Message- From: Grant, Tania (Tania) [SMTP:tgr...@lucent.com] Sent: Tuesday, December 15, 1998 2:23 PM To: 'bill.jacowl...@chr.carsys.philips.com'; emc-p...@ieee.org; 'Mike Hopkins' Subject: RE: Signatory for US based Manufacturer Mike, et al. [For lack of a comma, some people can be hanged!] What has never been clear to me is whether the manufacturer should also be established in the community or whether this is only applicable to the distributor who places the product on the market. Look at the two following sentence fragments without and with a comma. In my mind, placing a comma after the word 'manufacturer' definitely removes him from requiring to be part of the EU community. However, without the comma, I am less sure. I would like to see others comment on this! issued by the manufacturer or his authorized representative established within the Community..(no comma) issued by the manufacturer, or his authorized representative established within the Community.. (comma) Tania Grant, Lucent Technologies, Octel Messaging Division tgr...@lucent.com -- From: Mike Hopkins[SMTP:mhopk...@keytek.com] Sent: Tuesday, December 15, 1998 6:48 AM To: 'bill.jacowl...@chr.carsys.philips.com'; emc-p...@ieee.org Subject: RE: Signatory for US based Manufacturer I'll quote from the directive, Article 10, 1st paragraph: 1. In the case of apparatus for which the manufacturer has applied the standards referred to in Article 7 (1), the conformity of apparatus with this Directive shall be certified by an EC declaration of conformity issued by the manufacturer or his authorized representative established within the Community.. Seems clear to me that either the manufacturer, ... or his authorized representative established within the Community can sign the Declaration. Mike Hopkins mhopk...@keytek.com -Original Message- From: bill.jacowl...@chr.carsys.philips.com [SMTP:bill.jacowl...@chr.carsys.philips.com] Sent: Monday, December 14, 1998 4:07 PM To: emc-p...@ieee.org Subject: Signatory for US based Manufacturer Greetings to all: I am interested in finding out who usually acts as the Signatory for a EC Declaration of Conformance for a US based manufacturer. Thanks in advance, Bill Jacowleff VDO Control Systems 150 Knotter Drive Cheshire, CT 06410 Phone: 203 271-6394 FAX : 203 271-6200 Email: bill.jacowl...@chr.carsys.philips.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc
RE: Signatory for US based Manufacturer
That's certainly our interpertation. We do the tests here, sign the DofC here, then place a copy on file with one of our divisions in The Netherlands. Mike Hopkins mhopk...@keytek.com -Original Message- From: Robert Tims [SMTP:rt...@emx.ericsson.se] Sent: Tuesday, December 15, 1998 1:34 PM To: Mike Hopkins Cc: 'bill.jacowl...@chr.carsys.philips.com'; emc-p...@ieee.org Subject: Re: Signatory for US based Manufacturer Hi all, I have a question to clarify.. Is it to be understood that the EC DofC can be signed by the US manufacturer, and authorized copy of said document just has to reside with the rep in the EC? This could save me a lot of time and bs. Regards, Bob Tims Mike Hopkins wrote: I'll quote from the directive, Article 10, 1st paragraph: 1. In the case of apparatus for which the manufacturer has applied the standards referred to in Article 7 (1), the conformity of apparatus with this Directive shall be certified by an EC declaration of conformity issued by the manufacturer or his authorized representative established within the Community.. Seems clear to me that either the manufacturer, ... or his authorized representative established within the Community can sign the Declaration. Mike Hopkins mhopk...@keytek.com -Original Message- From: bill.jacowl...@chr.carsys.philips.com [SMTP:bill.jacowl...@chr.carsys.philips.com] Sent: Monday, December 14, 1998 4:07 PM To: emc-p...@ieee.org Subject: Signatory for US based Manufacturer Greetings to all: I am interested in finding out who usually acts as the Signatory for a EC Declaration of Conformance for a US based manufacturer. Thanks in advance, Bill Jacowleff VDO Control Systems 150 Knotter Drive Cheshire, CT 06410 Phone: 203 271-6394 FAX : 203 271-6200 Email: bill.jacowl...@chr.carsys.philips.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EN 61000-4-4
Place all cables in the clamp together I agree the standard is not clear, but the intent was always that all the I/O cables be placed in the clamp together. The idea is to simulate transients being coupled between lines in cable trays, especially where noisey ac lines are run near or adjecent to I/O lines. It's not likely the signals would be coupled to one line and not to another; in fact, because of the very fast pulses, everything gets very well coupled very quickly. Mike Hopkins mhopk...@keytek.com -Original Message- From: Collins, Erik D. [SMTP:collin...@lxe.com] Sent: Monday, December 14, 1998 10:40 AM To: 'emc-pstc list server' Subject: EN 61000-4-4 When performing EFT/B on signal and control lines using the capacitive coupling clamp, should you: 1. Place all cables in the clamp together 2. Place all cables in the clamp independently 3. Both Thanks Erik D. Collins EMI/EMC Approvals Engineer LXE Inc. Phone 770-447-4224 x3240 Fax 770-447-6928 Check out our website @: http://www.lxe.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Transient/Surge/Lightning Standards for DC power equipment
IEC 1000-4-5 is written with DC supplies in mind. In fact, generic and product standards in the EU require testing DC supply lines using IEC 1000-4-4 and 1000-4-5. Most surge simulators designed for surging AC lines can also be used for surging DC lines (some require an option to work on DC lines; some don't). In any case, the requirement is the same: a coupler -- usually via a an 8 to 10uF capacitor; a backfilter to allow voltage to be developed to the product being tested; and some kind of protection for the ac or dc source. This is generally built-in to modern surge generators for things like 48VDC lines up to 20-30A. Let me know if you want more information. Mike Hopkins mhopk...@keytek.com -Original Message- From: salba...@hns.com [SMTP:salba...@hns.com] Sent: Tuesday, December 08, 1998 5:04 PM To: emc-p...@majordomo.ieee.org Subject: Transient/Surge/Lightning Standards for DC power equipment Hello group, I was wondering if there is a specific standard written for testing DC powered equipment powered from a centralized DC power source ( Rectifier, battery ,etc. and also if there is a specific standard that is written for Antenna cables that carries RF signal from outdoor units to Indoor ones. The closest thing I got across is the ANSI C62.41 (IEEE 587 formally), IEC 1000-4-5. -- Thank you very much for your time Sincerely, Sarmad Albanna Compliance Engineer Hughes Network Systems (ph) (301) 428-5705 . - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
MITI
I've been asked about testing and certification requirements for MITI but have been unable to locate any information. Anyone out there know where i can find such ?? Tried their web page, but couldn't see anything about testing requirements. Thanks, Michael Hopkins mhopk...@keytek.com Tel: 1-978-275-0805 ext. 134 Fax: 1-978-275-0850 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: IEC 1000-X-X vs EN 61000-X-X
The IEC is simply renumbering the 1-x-X series to become the 61000-x-x series. Any new standard in that series will be numbered 61000-x-x. Existing standards are not going to be re-issued just to change the number, but when they are re-issued for whatever reason, the numbers will be changed. Hope this helps. Mike Hopkins mhopk...@keytek.com -Original Message- From: Bailey, Jeff [SMTP:jbai...@sstech.on.ca] Sent: Friday, October 09, 1998 12:53 PM To: 'EMC-PSTC' Subject: IEC 1000-X-X vs EN 61000-X-X Hello group, I currently have a number of the IEC 1000-X-X standards and test in accordance with them, EN 50082-1:1997 references the EN 61000-X-X standards. Can I safely continue to use my IEC 1000-X-X set or do I have to buy the EN 61000 series. any comments appreciated Thanks Jeff Bailey SST - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Room grounding
I absolutely disagree about having a separate ground for the shielded room. Any ac fault inside the room can potentially cause a personnel hazard, as will any lightning strike to the vicinity. A separate ground for the shielded room is acceptable ONLY if it is bonded to building ground. The risk may be minimal, but why take any at all. Mike Hopkins mhopk...@keytek.com -Original Message- From: lfresea...@aol.com [SMTP:lfresea...@aol.com] Sent: Tuesday, October 06, 1998 3:36 PM To: emc-p...@majordomo.ieee.org Subject: Room grounding Chaps, The grounding of a shield room has always been a tricky subject. In the US we have the NEC code that basically want's everything connected, which contradicts some EMC requirements. The Shield room hence needs some tricks: 1) One of the functions of the outer skin is to terminate impinging fields. Current is generated on the shield surface that will flow across joints and seams ( and hence leak into the chamber ) unless it's routed somewhere Earth. 2) While buildings usually have a good earth, they typically have a noisy earth. The last thing we need is building noise on our room, so an earth dedicated to the chamber is provided. 3) To stop building noise from using the shield room earth, all metallic connections are cut, and plastic used instead. This is where the NEC folks can get upset. Their concern is that the two grounds could lift with respect to each other I've never seen that happen, and I've gone looking for it. So that I can sleep at night, I ensure that an operator can't touch metal referenced to the different grounds at any one time. 4) Power supplied to the room has to be directly connected. To stop building noise from entering the room through this wiring, the noise is removed to the case of a filter. I've located my filters very close to the room single point room earth connection, so the noise can get there easily without crossing one of my room seams or joints. 5) Any equipment I use with the room is referenced to the room ground. Power for this equipment is filtered at the same point the room power is. Most instrumentation used in EMC is quiet so they don't supply much noise. I don't believe there is guess work involved with room grounding. The above is based on conversations with many room installers. I suggest that if you have specific questions, contact the folks that made yours. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EFT/B Generator for EN61000-4-4 Test
I can recommend Transient Speialists, Tel: 708 246 3297; fax 708 482 3972 or email lpit...@aol.com. They will do short term rentals plus provide some support. Mike Hopkins mhopk...@keytek.com -Original Message- From: Bailin Ma [SMTP:b...@namg.us.anritsu.com] Sent: Wednesday, October 07, 1998 2:28 PM To: emc-p...@ieee.org Subject: EFT/B Generator for EN61000-4-4 Test Hi Group, Do you know where I should go for renting a EFT/B Generator to run EN61000-4-4 Test? Thank you. Best Regards, Barry Ma - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Re[2]: Professional Equipment EN 61000-3-2
Be careful - one of the controversial points in 61000-3-2 is whether limits apply to actual power or to rated power. There is a working group in IEC dealing with this issue right now (I think they meet in November). I don't know which way they will go -- I've heard good arguments for using either one, but if I had to guess, I'd say it will end up being actual power being taken by the device during the test. Mike Hopkins mhopk...@keytek.com -Original Message- From: Crabb, John [SMTP:jo...@exchange.scotland.ncr.com] Sent: Friday, October 02, 1998 4:35 AM To: emc-p...@ieee.org Subject: RE: Re[2]: Professional Equipment EN 61000-3-2 Does this mean that all I have to do to exclude my professional equipment from the requirements of EN 61000-3-2 is to put a rating above 1000 W on the rating plate ? (From a safety point of view, the only requirement is that the actual power does not exceed the rated power, so even if my product only uses 600W, there is nothing stopping me rating it at 1001W !) John Crabb, Consultant Engineer, Product Safety, NCR Financial Solutions Group Ltd., Dundee, Scotland. -Original Message- From: MartinJP [SMTP:marti...@pebio.com] Sent: 29 September 1998 19:05 To: emc-p...@ieee.org; George; David L Subject:Re[2]: Professional Equipment EN 61000-3-2 Dave, I was not aware that the latest version of EN 61000-3-2 1998 excluded professional equipment rated above 1000 Watts. This is a very significant change to the standard. I have been having trouble locating the 1998 version. Could you provide me with a source to purchase this document from? Regards Joe Martin marti...@pebio.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Frequency Allocations
I've ordered the chart in June and recieved a post card thanking me for the order and notifying me that the charts are back ordered -- no idea when I'll recieve it. Mike Hopkins mhopk...@keytek.com -Original Message- From: ed.pr...@cubic.com [SMTP:ed.pr...@cubic.com] Sent: Thursday, August 20, 1998 1:53 PM To: Schanker, Jack; EMC-PSTC Subject: Re: Frequency Allocations Jack: Keeping track of the frequency allocations in all markets is a daunting task, especially considering the turbulent situation in Rongovia! While some may be able to give you some text or tabular references, let me give you a pointer to some nice wall art. At the US site, you can order a frequency chart that is about 30 wide by 24 tall and has more colors than a deluxe pizza, all for only about $4.00. Or, you can download the art in Adobe format, and break out your E size color plotter and creat your own wall murals. Here are the sites for USA and EN frequency allocation charts: http://www.ntia.doc.gov/osmhome/allochrt.html http://www.ero.dk/ Ed From: Schanker, Jack jschan...@mdsroc.com Subject: Frequency Allocations Date: Thu, 20 Aug 1998 11:01:05 -0400 To: emc-p...@ieee.org A recurring question that I get asked is what are the frequency allocations in fill in country name and can our model XXX be used in Rongovia? I've acquired detailed information about many countries (Europe, Australia, etc.) but still wish there were a comprehensive database somewhere. For the USA, Bennett Kobb has an excellent spectrum guide. Does anyone know of anything comparable covering the World ? The ITU table of allocations (can be found in FCC Part 2) is too general and vague to be really useful. Any ideas or pointers ? Jack Jacob Z. Schanker, P.E. Director of Agency Compliance Microwave Data Systems 175 Science Parkway Rochester, NY 14620 USA +716 242 8454 (voice) +716 241 5590 (fax) jschan...@mdsroc.com -- - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators). ---End of Original Message- -- Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 619-505-2780 Date: 08/20/1998 Time: 09:52:59 -- - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators).
RE: Transient overvoltage field study paper
I will get a copy and read what it has to say; however, the real issue today is not transient overvoltages, but transient currents! With the proliferation of overvoltage protectors in virtually every area -- transmission, distribution, residential, industrial -- the incidence of overvoltages should be pretty low. That doesn't mean nothing is happening -- it simply means the transient voltage suppressors are doing their job. What we really need is a study of transient CURRENTS to see what's really out there, but to my knowledge, no study has every been done. If anyone is aware of such a study, I'd love to see it. Mike Hopkins mhopk...@keytek.com -Original Message- From: Peter E. Perkins [SMTP:peperk...@compuserve.com] Sent: Monday, August 10, 1998 2:01 AM To: PSNetwork Subject: Transient overvoltage field study paper PSNet info on a paper of interest to this group... 'Transient Overvoltages in Low-Voltage Systems - A Field Study in Germany' by K Stimper - AENEA GmbH, G Ackerman - Deutsche Telekom AB, J Ehrler - Dehn Sohne GmbH, R Maier - Siemens AG and K Scheibe - Polytechnical College Kiel... published in July/August 1998 - Vol 14, No 4, IEEE Electrical Insulation Magazine. Key words: Transient, surge propagation, line voltage, occurrence rate This reader's abstract: The article digests to results of transient voltage measurements at about 40 locations over 700 measuring-months recording about 5000 incidents. The frequency of overvoltages found in this study were considerable lower than had been reported in some earlier studies. Conditions included the usual commercial/residential as well as industrial environments. They also measured transients on telecom lines and found them to be similar to earlier results. The results are for the conditions found in Germany - including their extensive use of underground facilities and very moderate occurrence of thunderstorms and lightning (on a worldwide basis). The results have been reported to IEC SC28A (IEC664 - Insulation Coordination in Low Voltage Equipment - including Creepages and Clearances in Equipment) for consideration in developing their requirements. This article, unfortunately, does not bring together data on a worldwide basis - from systems which do not make extensive use of underground systems nor areas of the world where there are considerable more thunderstorms and lightning activity. How could this work be extended to a worldwide basis? This article presents some basic information and is of interest to the PS community; I recommend it's reading to this list. (please don't ask me for copies, I'm not a library nor copy shop) - - - - - Peter E Perkins Principal Product Safety Consultant Tigard, ORe 97281-3427 +1/503/452-1201 phone/fax p.perk...@ieee.org email visit our website: http://ourworld.compuserve.com/homepages/peperkins - - - - - - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators).
