RE: RJ45 filtered connector
Some Ethernet history will explain the situation: 10BaseT Ethernet was designed to run on the same cable with telephone to simplify connectivity to cubicles. Non-telco pins were selected for Ethernet so RJ-45 jacks could accept either a telephone- or Ethernet plug. This combination wiring scheme was never very popular in the USA, and totally illegal in Europe (where telco wiring MUST be separated from all other wiring). All references to a combined Ethernet-telco wiring scheme were removed from NIC Installation Instructions around 1991 because European customers were being advised to violate the law!! The RJ-45 jack specified in for T-P in ANSI/IEEE 802.3 is an artifact of a 'connectivity improvement' that never made it. Also 1) TIA/EIA-968 replaced CFR 47 Part 68 now that ACTA is in charge 2) TIA/EIA-968 has no reference whatsoever to Ethernet 3) It is very difficult to change ANSI/IEEE802.3 retroactively David -Original Message- From: John Shinn [mailto:john.sh...@sanmina-sci.com] Sent: Wednesday, January 02, 2002 11:56 AM To: david_ster...@ademco.com; john.sh...@sanmina-sci.com; ows...@cisco.com; rhe...@vicon-cctv.com; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector David: The pertinent and defining specification is contained in the FCC Rules, 47 FR Part 68. Everything else is a misuse of the original intent. An RJ11 is also defined there. ALL RJ designations are specified for use within the telephone industry. Is is too bad that the Networking groups chose to use the same designation for the same modular plug with different wiring. That is the same as calling all DB-25 connectors an RS-232 connector, even if used for a different application. John -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of david_ster...@ademco.com Sent: Wednesday, December 26, 2001 9:12 AM To: john.sh...@sanmina-sci.com; ows...@cisco.com; rhe...@vicon-cctv.com; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector John, The pertinent specification, ANSI/IEEE 802.3 (a.k.a. ISO/IEC8802.3), describes the Ethernet physical layer plug/jack as an RJ-45. ArcNet twisted pair was RJ-11. If you purchase jacks that include internal filters, be sure the filters are designed for Ethernet/F-E (10BaseT 100BaseTX). Some ferrite filters are designed to suppress digital noise in voice telephone lines. These ferrites can cause 'back pressure' on the digital signal, resulting in cable-length sensitivity; i.e. the impedance curve no longer meets 802.3. You can live with cable-length sensitivity on emissions (to 'isolate' the EUT), but expect diminished RF immunity with certain cable lengths when filters are inserted in the T-P line. Ethernet components are rigorously tested for 802.3 compliance (waveforms, jitter, SQE, bit-error rate) and for compatibility with components from other manufacturers. These compatibility-suite tests are performed without any additional T-P line filters. Any altered interface is your responsibility; results may or may not represent real world installations. David -Original Message- From: John Shinn [mailto:john.sh...@sanmina-sci.com] Sent: Thursday, December 20, 2001 6:10 PM To: 'Bill Owsley'; 'John Shinn'; 'Reginald Henry'; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector Acutally, the term RJ is used by the FCC for designating connectors that are part of the registration (now approval) process. So why would you want to call a ethernet connector by a designation used by the telephone industry? I am not going to police the use of the term, but I wanted to put that information out to everyone. Regards, John Shinn -Original Message- From: Bill Owsley [mailto:ows...@cisco.com] Sent: Thursday, December 20, 2001 2:32 PM To: John Shinn; 'Reginald Henry'; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector so if we called it an RJ-48C, would that be better ?? At 04:56 PM 12/20/2001 , John Shinn wrote: Although it may suprise some, and I may get flak, but an RJ45 connector is an specific configuration used exclusively for a programmable data connection. It has a specific wiring configuration. The RJ stands for Registered Jack. This is an FCC designation of that specific configuration. There is nothing against using an 8-pin modular plug/jack for 10Base-Tor 100Base-T, or even microphone inputs to my Ham radio, but do not call it a RJ45. Now, yes, there are several vendors that produce shielded and filtered 8-pin modular jacks. I remember using them and working with several vendors a few years ago, but I would suggest you look at the website or catalogs of the major connector suppliers. John Shinn, P.E. Manager, Lab. Operations. Sanmina-SCI -Original Message- From: owner-emc-p...@majordomo.ieee.org [ mailto:owner-emc-p...@majordomo.ieee.org]On mailto:owner-emc-p...@majordomo.ieee.org%5DOn
Re: EMC-related safety issues
It's no different this side of the Pond. -- From: John Woodgate j...@jmwa.demon.co.uk To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Wed, Jan 2, 2002, 3:19 PM I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in 20020102192217.PBJZ20715.femail25.sdc1.sfba.home.com@[65.11.150.27] ) about 'EMC-related safety issues', on Wed, 2 Jan 2002: What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This reflects a prevalent attitude in the UK Health and Safety regulatory field. Like the Italian criminal code, it presupposes that there is no such thing as an accident for which no-one can be blamed, and the victim(s) is/are NEVER to blame. The result is that after every accident a hunt begins for a scape-goat, and, willy-nilly, one is found, unless all bodies concerned have costly lawyers to pass the buck around interminably or have other ways of exerting political influence. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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: EMC-related safety issues
If they meant "radio compass," that is a different can of monkeys. The radio compass was traditionally the indicator for the ADF set , pointing to the ground station, and was usually mounted so as to revolve in front of a scale which rotated with the aircraft's' magnetic heading. A noisy switching power supply could well interfere with a low-frequency receiver. But (in MY opinion) the Guide does not say enough about what actually happened. Cortland (My thoughts, not Alcatel's!) Mike Hopkins wrote: 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 HopkinsThermo KeyTek --- 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: Korea EMC/Safety Requirements for ITE equipment
Hi Ted, Approval for ITE telecom equipment in Korea is issued by Radio Research Laboratory (RRL), which is organized under Korea's Ministry of Information and Communications (MIC). Your memory's right: in-country testing will be required for EMC (emissions and immunity) -- and for telecom function and safety if your terminal has public network connections. Unfortunately, your existing test reports won't eliminate the need for testing by an RRL accredited lab. Testing will be to standards essentially the same as what you've already tested, but the reports in the application to RRL will still have to come from one of their accredited labs. Hope this helps. We're happy to answer any other questions you've got. Best regards, -Fred Borda Compliance International At 04:02 PM 1/2/02 -0500, Carr, Ted wrote: Hi all, Happy New Year, I just found out that we maybe shipping our product to Korea soon. I would like to know the Korea EMC/Safety requirements for ITE equipment . I seem to remember some requirement for in-country testing. Am I correct in this? What if anything does this in-country testing require? Would appreciate any help that can be given. We normally test all are products for UL,CSA,TUV and perform in house EMC testing to EN55024 and EMI to FCC/EN55022:1998 Class A. My company's product is a point of sale terminal. Thanks in advance for the help. Ted Carr mailto:ted.c...@gtech.comted.c...@gtech.com Fred Borda Director Marketing Business Development Compliance International www.typeapproval.com The experts in telecommunications equipment type approval across the Asia-Pacific region 4713 First Street, Suite 280 Pleasanton, California 94566-7362 USA Tel +1.925.417.5571 (direct) Fax +1.925.417.5574 Mobile +1.650.740.5762 fbo...@typeapproval.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.
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
Electric Shock and Water
My apologies if this is just too naive... I am trying to explain to a collegue why there are so many cautions against mixing water with electricity. He is not the type to accept common sense as an answer. This is what I have reasoned so far... MAL-OPERATION Water is generally conductive. If it enters the area of a chassis that houses control elements such as relays or switches, it can short circuit the control elements and cause the affected device to operate unexpectedly, and sometimes in unexpected ways. ENERGIZING SURFACES Water is generally conductive. If it enters a chassis containing hazardous voltages it is possible it may act as a conductor of the voltage to an otherwise un-energized conductive surface. If the conductive surface, for whatever reason, is itself not sufficiently grounded, it can carry hazardous voltage potentials. INCREASED LEAKAGE CURRENTS Water is generally conductive. If you are working on a chassis and accidentally touch an energized contact, you may not experience any shock because there is no current path between you and the voltage source supplying the contact. Let us assume the contact is energized by a local AC mains. There is always SOME leakage current possible from where you are standing back to a grounded point. Usually it is a very small leakage. However, if you are standing in water, the leakage current is likely to be much higher, and you may experience a serious electric shock from your accidental touching of a contact. AVALANCHE EFFECT Water is generally conductive. If it enters a chassis with high power electrical components, it can instigate an avalanche of failure that results in the release of a lot of energy. For example, the water can provide a short circuit between two potentials. As it carries current, the water may heat up quite rapidly, in doing so it creates steam. The effects of the heat and steam may then provide an even lower resistance path for additional current flow...and so an avalanche of conductivity (from less conductive to more conductive) is started... I welcome any comments and additional generic scenarios. Regards, Jason Mallory Product Safety Consultant. -- __ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.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.
Re: EMC-related safety issues
I totally agree with the sentiments expressed. My point was that IEE safety guide seemed to give aid and comfort to those who feel otherwise and I think this is a dangerous trend which needs to be opposed, not appeased. -- From: Gary McInturff gary.mcintu...@worldwidepackets.com To: Ken Javor ken.ja...@emccompliance.com, cherryclo...@aol.com, emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 4:08 PM Did the camera have proximal cause to the event that befell the child, well not unless it fell of of the ceiling or the tripod fell over and hit the infant, or the camera overheated and started a fire. Other than that the Lawyers need to dig their heads out - juries as well. They are just trying to chase the money. Cameras don't cause disease likes SIDS. They don't cause buildings to collapse, or burglaries or whatever else might befall the baby They are just a convenience. If they an additional input path to the parents may stop, but the actual monitoring (or the failure of monitoring) neither helped or hindered the health of the child. The camera manufacturer, even if this is sold as a baby monitor, I can't see how holding the camera manufacturer responsible can even be considered, except that it gives the lawyers somebody to sue with some money. I suppose it might give the parents a misplaced sense of (and I hate this word) closure because they can blame some body, rather than just life, fate, or whatever. I don't doubt your statement that somebody is trying to hold the manufacturer responsible, I just point out that it is asinine and in my opinion inexcusable to do so. Recorded history doesn't show a huge plethora of infant deaths because parents weren't able to have a video camera in the room. Gary -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 11:22 AM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!).
RE: EMC-related safety issues
Did the camera have proximal cause to the event that befell the child, well not unless it fell of of the ceiling or the tripod fell over and hit the infant, or the camera overheated and started a fire. Other than that the Lawyers need to dig their heads out - juries as well. They are just trying to chase the money. Cameras don't cause disease likes SIDS. They don't cause buildings to collapse, or burglaries or whatever else might befall the baby They are just a convenience. If they an additional input path to the parents may stop, but the actual monitoring (or the failure of monitoring) neither helped or hindered the health of the child. The camera manufacturer, even if this is sold as a baby monitor, I can't see how holding the camera manufacturer responsible can even be considered, except that it gives the lawyers somebody to sue with some money. I suppose it might give the parents a misplaced sense of (and I hate this word) closure because they can blame some body, rather than just life, fate, or whatever. I don't doubt your statement that somebody is trying to hold the manufacturer responsible, I just point out that it is asinine and in my opinion inexcusable to do so. Recorded history doesn't show a huge plethora of infant deaths because parents weren't able to have a video camera in the room. Gary -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 11:22 AM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to
Re: EMC-related safety issues
It appears that a lot depends on what we mean by the word safety. If this means the elimination of as-yet-unknown risks, why, nothing can be shown to be safe. If we mean the prevention of hazards that are reasonably predictable, we do that already. Or should! The existence of standards which require us to do so is some indication that not everyone DOES. Happy New Year! Cortland (my words, not my employers') --- 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.
Touch-Pad ESD immunity
Dear Ann Landers, I've always had trouble with peripherals. Keyboards and mice that were CE marked and looked like such good prospects have mostly turned out to be fickle. Well, I've been involved with a touchpad for about five months now. When I first bought it, we were so happy. Whenever we were together it, it could read my mind. A tap of my finger and it knew just what to do. And then this ESD gun comes along. One zap and BOOM! The touchpad turns its back on me. It won't respond at all! I tried talking to it...but it just gave me the cold shoulder. I suggested counseling...still no response. I threatend to go and get a mouse...no response. Well, I finally had to just take a deep breath and go through with it. I cycled power. Well it now responds to me... but I don't know if I'll ever trust it around an ESD gun again. I don't know if our relationship will ever be the same. Signed Out of touch in New York OK OK The real question is... does anybody have some words of advice regarding touchpads. I am testing a unit which consists of a keyboard/touchpad combination. The touchpad is approx 1.5 x 1.5 and is able to sense a sliding or tapping finger. The touchpad is used to perform all of the functions that a mouse typically performs. I am assuming that it has some sort of capacitive sense circuit which can tell when your finger slides across the pad or taps on the pad. I have one that gets all out of whack with 8KV ESD. i.e. the touchpad becomes unresponsive and it stops software execution in our host system. Unfortunately, this is one of those instances where we don't build the keyboard/touchpad; so my bag of fix tricks is limited. Probably limited to seeing if another manufacturer produces a keyboard/touchpad with better performance. Or, am I slamming my head against the wall on this one? The keyboard/touchpad is already CE marked by its manufacturer. Is this typical? Are all touchpads (even CE marked ones) ESD sensitive? Do I just live with it? Am I over-testing this touchpad? Overall... I have had REALLY bad experiences with CE marked keyboards and mouses. Now I have trouble with our first touchpad. We typically use a capacitive filter on our inputs and we typically put a ferrite on the cable...yet still trouble. Is this typical of what others see? Any words of advice, experience... would be appreciated. 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 | --- 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: EN60529
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD0@flbocexu05) about 'EN60529', on Wed, 2 Jan 2002: It is referenced in the OJ under the LVD, yet a reading of the standard indicates that it is a basic standard intended to be referenced in product standards. It appears to be a mistake, because, as you say, it is a Basic Standard. Astonishing as it must seem to mere mortals, the CENELEC Technical Board is not utterly infallible. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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: EMC-related safety issues
I read in !emc-pstc that Cortland Richmond cortland.richm...@alcatel.co m wrote (in 3c3365ca.d3acb...@alcatel.com) about 'EMC-related safety issues', on Wed, 2 Jan 2002: The citation for the referenced incident was Compliance Engineering (CE magazine), the European edition, for November/December 1996. It must be true if it was printed in a magazine, of course. Especially that one. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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: EMC-related safety issues
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in 20020102192217.PBJZ20715.femail25.sdc1.sfba.home.com@[65.11.150.27] ) about 'EMC-related safety issues', on Wed, 2 Jan 2002: What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This reflects a prevalent attitude in the UK Health and Safety regulatory field. Like the Italian criminal code, it presupposes that there is no such thing as an accident for which no-one can be blamed, and the victim(s) is/are NEVER to blame. The result is that after every accident a hunt begins for a scape-goat, and, willy-nilly, one is found, unless all bodies concerned have costly lawyers to pass the buck around interminably or have other ways of exerting political influence. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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.
Korea EMC/Safety Requirements for ITE equipment
Hi all, Happy New Year, I just found out that we maybe shipping our product to Korea soon. I would like to know the Korea EMC/Safety requirements for ITE equipment . I seem to remember some requirement for in-country testing. Am I correct in this? What if anything does this in-country testing require? Would appreciate any help that can be given. We normally test all are products for UL,CSA,TUV and perform in house EMC testing to EN55024 and EMI to FCC/EN55022:1998 Class A. My company's product is a point of sale terminal. Thanks in advance for the help. Ted Carr ted.c...@gtech.com mailto:ted.c...@gtech.com attachment: Ted_Carr.vcf
Re: EMC-related safety issues
Personally, I could list a ton of stuff that would instill fear and loathing amongst the fainest of EMC hearts. Sitting in a jet airliner at the end of the runway readying for take-off and watching the cabin lights dim slightly in sync with the sweep of the main radar dish just a couple of hundred yards away. ESD events in the kitchen area of the airliner causing the phone in the cockpit at the other end of the plane to ring making the pilot pickup to answer. ESD events in the control tower of an airport causing the computer and other essential equipment to crash. Enough spurious radiation events to require laptops and cell phones to be turned off upon takeoff or landing. Why? Am I and hundreds of others trusting out lives on something so ... sensitve? But we think nothing of dialing up the cell phone inside a car packed with digital controls for things like the brakes, the accelerator, gas control ... The automobile industry does its best to test for the severest of electrical events with lightning simulations. But what about internal to the car less than a meter away? And by the way, do they allow cell phones and laptops in that airport control tower? Do they have conductive floors and require people to wear ESD proof shoes? Define safety related issues? Does it necessarily have to do with physical safety? How about the spurious radiations from an ATM being decoded by someone nearby to gain access to your bank account to drain it? Sorry. Must be the Day After New Year's Day effect ... - Doug McKean --- 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.
EN60529
Perhaps someone can clear up my confusion. EN60529 covers degrees of protection (water, dust, etc.) provided by enclosures. It is referenced in the OJ under the LVD, yet a reading of the standard indicates that it is a basic standard intended to be referenced in product standards. However, EN60950 provides only an informative reference to the standard and a set of should statements are listed in Annex T. It appears that an analysis is required for a particular outdoor ITE to determine which parts of EN60529 are to be applied. Unlike many other directives, the LVD does not mandate the intervention of a Notified Body when a harmonized standard is applied in part. However, if challenged, the manufacturer may submit a report from a Notified Body (Article 8). Since neither EN60950 nor EN60529 is clear as to which sections of EN60529 must be applied to a particular ITE intended for outdoor use, I understand the manufacture must determine how to apply EN60529 (with or without the assistance of a Notified Body), and the Declaration of Conformity must list both EN60950 and EN60529. It is insufficient to list just EN60950. Is my understanding correct? Richard Woods Sensormatic Electronics Tyco International --- 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: 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 levels of what one could call 'spurious' emissions include EN 61800-3 (industrial drives) and EN 50091-2:1996 (uninterruptible power systems). And I'm not sure whether you would call the leakages from ISM equipment (as defined by CISPR 11) 'spurious'. Is an induction furnace or dielectric heater an intentional transmitter? The semantics of the phrase 'spurious emissions' get very complicated the wider one casts one's net and what one might call the 'spurious emissions' from some ISM equipment can be extremely powerful indeed. But in any case I disagree with your claim that the limited set of possible spurious emissions that you say you concerned with have such low powers that it is impossible for them to only affect radio receivers. I refer again to the airplane compass interference example given in the IEE's guide on EMC and Functional Safety. A compass in an airliner is not a radio receiver, yet this one was interfered with by a laptop computer in the passenger cabin. I don't have many more details on the official investigation into this incident but it might have been that the laptop computer concerned did not comply with Title 47, part 15B of the US Code of Federal Regulations so its spurious emissions were higher than they should have been. On the other hand the passenger cabin is a long way from the pilots instrumentation console so it may be that a similar laptop that did meet Title 47, part 15B of the US Code of Federal Regulations might have caused the same level of interference if it was closer to the compass's electronics. Some electronics are simply very sensitive to demodulation of spurious emissions at specific frequencies, whether by accident or intention of their design or manufacture, so it is impossible to be
RE: EMC-related safety issues
Hi Keith, I do understand Ing. Gert Gremmen's comments, but still wonder how the airplane compass I mentioned earlier was interfered with by the passenger's laptop. I really can't say about any specific airplanes compass but I can help try to understand what can cause such an effect. Compasses typically shouldn't be affected by a laptop unless that laptop is in very close proximity to the compass or the laptop has a large current draw. I've noticed the compass in my plane swing when I engage the starter and after the motor is running it indicates a slightly different heading then before engine starting. I've used several laptops in my plane and have never noticed a change in compass heading, it appears that the compass in my plane is not very susceptible to such effects. Of course compasses on large planes are typically remotely located magnometers which feed information to cockpit displays such as horizontal situation indicators, radars, moving map displays, air data computers, sferics devices and so on. This data feed can be digital or analog but typically its a databus like the ARINC 429. I doubt that the compass was actually effected on this plane, most likely, it was the data link that was causing problems (we can only speculate at this time). Since I now work on radar systems and not airplanes, I feel confident that I am not overstating the importance of my station in life by saying this is quite a serious problem and should continue to be addressed to insure there is no loss of life due to commercial electronics running within a transport category aircraft. Remember, when operating in instrument meteorological conditions, neither the pilots, or the autopilot knows which is up, down, north, east, south, or west without the flight instruments, navigation receivers, and/or the compass. I believe your other points on EMC and safety are well stated. I've downloaded your core document and hope to read it and get back to you with any useful criticisms. Edmund A Woodcox Specialty Engineering Electromagnetic Environmental Effects = LOCKHEED MARTIN Naval Electronics Surveillance Systems-Syracuse PO Box 4840 EP5-D5MD45 Syracuse, NY 13221-4840 === Phone: 315-456-2650 Fax: 315-456-0509 Email: edmund.a.wood...@lmco.com -- From: cherryclo...@aol.com[SMTP:cherryclo...@aol.com] Reply To: cherryclo...@aol.com Sent: Wednesday, January 02, 2002 11:24 AM To: emc-p...@majordomo.ieee.org Subject: re: EMC-related safety issues I believe there are great problems with the use of the phrase 'spurious emissions' in any context save that of a standard or law which defines just what that phrase means. I sincerely hope I am not one of those who is ever ready to overstate the importance of their station in life ! But I do notice the following: a) Very great commercial pressures to design very low-cost products in very short timescales b) A general lack of expertise in the relationship between EMI and safety in commercial design and manufacturing companies c) Great yawning gaps on EMC-related safety issues exist in both the commercial EMC standards (almost all of which were not written with safety issues in mind) and in the commercial safety standards (almost all of which were not written with EMC in mind). Since, as someone put it recently: We are now utterly dependant on technology for all aspects of our life the above issues do cause me to worry about the future. Read my article EMC-related Functional Safety in ITEM UPDATE 2001 (pages 52-59) for more detail on my worries (www.rbitem.com) and see if you agree. More senior EMC people than me share my concerns. I am sure that all the safety engineers reading this will understand, as many EMC and other engineers do not appear to, that just because nothing bad has happened so far it doesn't guarantee that something bad will not happen tomorrow. I understand that under European Product Liability law (and I suspect in US product liability law too) evidence of a historical lack of safety problems is not considered sufficient proof that a design is as safe as people generally have the right to expect. I do understand Ing. Gert Gremmen's comments, but still wonder how the airplane compass I mentioned earlier was interfered with by the passenger's laptop. Regards, Keith Armstrong In a message dated 02/01/02 15:47:52 GMT Standard Time, ken.ja...@emccompliance.com writes: Subj:Re: EMC-related safety issues Date:02/01/02 15:47:52 GMT Standard Time From:ken.ja...@emccompliance.com (Ken Javor) Sender: owner-emc-p...@majordomo.ieee.org Reply-to: ken.ja...@emccompliance.com (Ken Javor) To:cherryclo...@aol.com,
Re: EMC-related safety issues
I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. * To control EMC correctly for functional safety reasons, hazard and risk assessments must take EM environment, emissions, and immunity into account. The following should be addressed: 1) The EM disturbances, however infrequent, to which the apparatus might be exposed 2) The foreseeable effects of such disturbances on the apparatus 3) How EM disturbances emitted by the apparatus might affect other apparatus (existing or planned)? 4) The foreseeable safety implications of the above mentioned disturbances (what is the severity of the hazard, the scale of the risk, and the appropriate safety integrity level?) 5) The level of confidence required to verify that the above have been fully considered and all necessary actions taken to achieve the desired level of safety * Please - anybody and everybody out there - tell me if there is anything wrong with this engineering approach to EMC-related functional safety. Involve experts you know who are not subscribers to emc-pstc too. Please be as detailed as you can be. If I receive no constructive comments about the above 5-point approach by the end of January I will assume that the IEE's guide is on the right tracks and will not need major revisions. You can send any comments to me via emc-pstc or directly to keith.armstr...@cherryclough.com or cherryclo...@aol.com. Interestingly, my reading of IEC/TS 61000-1-2 leads me to believe that it follows the same
Re: EMC-related safety issues
I read in !emc-pstc that cherryclo...@aol.com wrote (in 63.44c9e61.29648...@aol.com) about 'EMC-related safety issues', on Wed, 2 Jan 2002: Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. I quite specifically said that I refrained from comment on it and I did not comment on it. Furthermore, I don't intend to. Make that into a 'negative impression', if you can reasonably do so. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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: RJ45 filtered connector
David: The pertinent and defining specification is contained in the FCC Rules, 47 FR Part 68. Everything else is a misuse of the original intent. An RJ11 is also defined there. ALL RJ designations are specified for use within the telephone industry. Is is too bad that the Networking groups chose to use the same designation for the same modular plug with different wiring. That is the same as calling all DB-25 connectors an RS-232 connector, even if used for a different application. John -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of david_ster...@ademco.com Sent: Wednesday, December 26, 2001 9:12 AM To: john.sh...@sanmina-sci.com; ows...@cisco.com; rhe...@vicon-cctv.com; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector John, The pertinent specification, ANSI/IEEE 802.3 (a.k.a. ISO/IEC8802.3), describes the Ethernet physical layer plug/jack as an RJ-45. ArcNet twisted pair was RJ-11. If you purchase jacks that include internal filters, be sure the filters are designed for Ethernet/F-E (10BaseT 100BaseTX). Some ferrite filters are designed to suppress digital noise in voice telephone lines. These ferrites can cause 'back pressure' on the digital signal, resulting in cable-length sensitivity; i.e. the impedance curve no longer meets 802.3. You can live with cable-length sensitivity on emissions (to 'isolate' the EUT), but expect diminished RF immunity with certain cable lengths when filters are inserted in the T-P line. Ethernet components are rigorously tested for 802.3 compliance (waveforms, jitter, SQE, bit-error rate) and for compatibility with components from other manufacturers. These compatibility-suite tests are performed without any additional T-P line filters. Any altered interface is your responsibility; results may or may not represent real world installations. David -Original Message- From: John Shinn [mailto:john.sh...@sanmina-sci.com] Sent: Thursday, December 20, 2001 6:10 PM To: 'Bill Owsley'; 'John Shinn'; 'Reginald Henry'; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector Acutally, the term RJ is used by the FCC for designating connectors that are part of the registration (now approval) process. So why would you want to call a ethernet connector by a designation used by the telephone industry? I am not going to police the use of the term, but I wanted to put that information out to everyone. Regards, John Shinn -Original Message- From: Bill Owsley [mailto:ows...@cisco.com] Sent: Thursday, December 20, 2001 2:32 PM To: John Shinn; 'Reginald Henry'; emc-p...@majordomo.ieee.org Subject: RE: RJ45 filtered connector so if we called it an RJ-48C, would that be better ?? At 04:56 PM 12/20/2001 , John Shinn wrote: Although it may suprise some, and I may get flak, but an RJ45 connector is an specific configuration used exclusively for a programmable data connection. It has a specific wiring configuration. The RJ stands for Registered Jack. This is an FCC designation of that specific configuration. There is nothing against using an 8-pin modular plug/jack for 10Base-Tor 100Base-T, or even microphone inputs to my Ham radio, but do not call it a RJ45. Now, yes, there are several vendors that produce shielded and filtered 8-pin modular jacks. I remember using them and working with several vendors a few years ago, but I would suggest you look at the website or catalogs of the major connector suppliers. John Shinn, P.E. Manager, Lab. Operations. Sanmina-SCI -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Reginald Henry Sent: Thursday, December 20, 2001 10:51 AM To: emc-p...@majordomo.ieee.org Subject: RE:RJ45 filtered connector To All, Can anyone out there tell me where I would be able to purchase a fully shielded and filter RJ45 connector that is Bulkhead mountable. The RJ45 must be able to handle data rates from 10Base T to 100Base T I will be performing CE testing in the chamber so it must be bulkhead mountable ! Thanks and Happy Holidays to YOU ALL ! Reg --- 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:
RE: -2dB margin
Just got back from Christmas vacation, but I'll wade in now... There is nothing in CISPR 22 that refers to a 2 dB margin for compliance when a single sample is tested. The only document I ever recall seeing that requirement in is VDE 0871/6.78, paragraph 4.1.3.1. This document was published in 1978 and is long obsolete. I suspect that many people got used to the 2 dB margin requirement from dealing with the VDE in years past and it is now part of the folklore of EMC testing. Ghery S. Pettit Intel -Original Message- From: George Stults [mailto:george.stu...@watchguard.com] Sent: Monday, December 24, 2001 11:43 AM To: 'emc-p...@majordomo.ieee.org' Subject: -2dB margin Hello Group, I've been looking into the 80/80 rule for CISPR 22 compliance for mass produced equipment. I have found a description of the statistics in CISPR 22 :1997 Section 7.1 and 7.2. Its been my understanding that for testing at OATS, if the product has 2dB or less margin, then these statistical methods are required. Is that correct? And, where does the reference to '2dB margin' come from? Thanks in advance George S. --- 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: Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about Spectrum Analyzer
Hi John and all, I am currently writing a book about the subject of RF spectrum analysis, which will be ready within the next 3 months. I started more than four years ago, and now I have 322 pages and more than 250 drawings. I cover the applications, theory and circuits used in five decades of spectrum analysis. There is also a chapter where some practical measurements are shown in some detail, including screenshots and so on. Unfortunately --- (always a setback) --- it is in German I don't know if there is a widespread demand for such a book, I began writing because I couldn't find almost no information via Internet, and also the great HP appnote 150 is not available any more. I'll be interested in your feedback Jochen Feldhaar DH6FAZ John Woodgate schrieb: [big snip] --- 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: EMC-related safety issues
I believe there are great problems with the use of the phrase 'spurious emissions' in any context save that of a standard or law which defines just what that phrase means. I sincerely hope I am not one of those who is ever ready to overstate the importance of their station in life ! But I do notice the following: a) Very great commercial pressures to design very low-cost products in very short timescales b) A general lack of expertise in the relationship between EMI and safety in commercial design and manufacturing companies c) Great yawning gaps on EMC-related safety issues exist in both the commercial EMC standards (almost all of which were not written with safety issues in mind) and in the commercial safety standards (almost all of which were not written with EMC in mind). Since, as someone put it recently: We are now utterly dependant on technology for all aspects of our life the above issues do cause me to worry about the future. Read my article EMC-related Functional Safety in ITEM UPDATE 2001 (pages 52-59) for more detail on my worries (www.rbitem.com) and see if you agree. More senior EMC people than me share my concerns. I am sure that all the safety engineers reading this will understand, as many EMC and other engineers do not appear to, that just because nothing bad has happened so far it doesn't guarantee that something bad will not happen tomorrow. I understand that under European Product Liability law (and I suspect in US product liability law too) evidence of a historical lack of safety problems is not considered sufficient proof that a design is as safe as people generally have the right to expect. I do understand Ing. Gert Gremmen's comments, but still wonder how the airplane compass I mentioned earlier was interfered with by the passenger's laptop. Regards, Keith Armstrong In a message dated 02/01/02 15:47:52 GMT Standard Time, ken.ja...@emccompliance.com writes: Subj:Re: EMC-related safety issues Date:02/01/02 15:47:52 GMT Standard Time From:ken.ja...@emccompliance.com (Ken Javor) Sender: owner-emc-p...@majordomo.ieee.org Reply-to: A HREF=mailto:ken.ja...@emccompliance.com;ken.ja...@emccompliance.com/A (Ken Javor) To:cherryclo...@aol.com, emc-p...@majordomo.ieee.org I believe that your concept of spurious emission is independent of the magnitude of the emission, and is only associated with the idea that the emission is not an antenna-connected intentional rf link. So you comfortably associate an rf welder and a laptop computer as both spurious sources of rf energy and then your statement that, Any electromagnetic emissions, whether conducted or radiated, including spurious emissions (however you wish to define the word 'spurious') can be demodulated by the non-linear processes in semiconductors, vacuum tubes, and the like. So the spread of possible problems goes beyond merely preventing the reception of radio communications, follows. But I maintain that is a dangerous association and that it is essential to distinguish between equipment such as ITE which can only disturb radio links (cause rfi) and more powerful sources which can disturb ITE, such as your welder. The reason this distinction must be drawn is that there are people out there who are ever ready to overstate the importance of their station in life and claim that compliance with FCC/CISPR limits or military or aerospace emission limits is safety-critical and that non-compliance may result in loss of life. Such is not the case, such people damage the credibility of the profession profoundly and I remain ever vigilant in disputing such assertions whenever they arise. If I have given offense, I apologize. I end by quoting Ing. Gert Gremmen, in a related posting, Limits for emission are essentially to protect (radio)receivers... I have never met an equipment lacking immunity of any field strength at any frequency within 60 dB above the limits in f.a. CISPR22 that was not a (frequency selective) receiver. That is precisely correct. Ken Javor -- From: cherryclo...@aol.com To: ken.ja...@emccompliance.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Wed, Jan 2, 2002, 8:45 AM 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
Re: EMC-related safety issues
Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. * To control EMC correctly for functional safety reasons, hazard and risk assessments must take EM environment, emissions, and immunity into account. The following should be addressed: 1) The EM disturbances, however infrequent, to which the apparatus might be exposed 2) The foreseeable effects of such disturbances on the apparatus 3) How EM disturbances emitted by the apparatus might affect other apparatus (existing or planned)? 4) The foreseeable safety implications of the above mentioned disturbances (what is the severity of the hazard, the scale of the risk, and the appropriate safety integrity level?) 5) The level of confidence required to verify that the above have been fully considered and all necessary actions taken to achieve the desired level of safety * Please - anybody and everybody out there - tell me if there is anything wrong with this engineering approach to EMC-related functional safety. Involve experts you know who are not subscribers to emc-pstc too. Please be as detailed as you can be. If I receive no constructive comments about the above 5-point approach by the end of January I will assume that the IEE's guide is on the right tracks and will not need major revisions. You can send any comments to me via emc-pstc or directly to keith.armstr...@cherryclough.com or cherryclo...@aol.com. Interestingly, my reading of IEC/TS 61000-1-2 leads me to believe that it follows the same general approach as the IEE's guide. Regards, Keith Armstrong In a message dated 31/12/01 21:58:43 GMT Standard Time, j...@jmwa.demon.co.uk writes: Subj:Re: EMC-related safety issues Date:31/12/01 21:58:43 GMT Standard Time From:j...@jmwa.demon.co.uk (John Woodgate) Sender:owner-emc-p...@majordomo.ieee.org Reply-to: A HREF=mailto:j...@jmwa.demon.co.uk;j...@jmwa.demon.co.uk/A (John Woodgate) To:emc-p...@majordomo.ieee.org I read in !emc-pstc that cherryclo...@aol.com wrote (in 17c.18c06c2.296 20...@aol.com) about 'EMC-related safety issues', on Mon, 31 Dec 2001: Quite a number of EMC and Safety experts took part in creating the IEE's Guide on EMC and Functional Safety, including a lawyer who specialises in high-tech issues. You will find their names listed at the end of the 'core' of the guide (downloadable from www.iee.org.uk/Policy/Areas/Electro). Many of these experts also involved their colleagues and others so we got a very wide spread of opinion. My comments referred to the IEC work, specifically verbal reports from people involved. You will have noticed that the work culminated in a TS, not a standard as originally envisaged. That in itself may be an indication of certain difficulties in its passage through IEC. I think that a passionate defence of the IEE document (which I have not studied, so will not comment on) *may* also be an indication that there is more emotion surrounding this subject than is desirable. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero.
Re: EMC-related safety issues
I believe that your concept of spurious emission is independent of the magnitude of the emission, and is only associated with the idea that the emission is not an antenna-connected intentional rf link. So you comfortably associate an rf welder and a laptop computer as both spurious sources of rf energy and then your statement that, Any electromagnetic emissions, whether conducted or radiated, including spurious emissions (however you wish to define the word 'spurious') can be demodulated by the non-linear processes in semiconductors, vacuum tubes, and the like. So the spread of possible problems goes beyond merely preventing the reception of radio communications, follows. But I maintain that is a dangerous association and that it is essential to distinguish between equipment such as ITE which can only disturb radio links (cause rfi) and more powerful sources which can disturb ITE, such as your welder. The reason this distinction must be drawn is that there are people out there who are ever ready to overstate the importance of their station in life and claim that compliance with FCC/CISPR limits or military or aerospace emission limits is safety-critical and that non-compliance may result in loss of life. Such is not the case, such people damage the credibility of the profession profoundly and I remain ever vigilant in disputing such assertions whenever they arise. If I have given offense, I apologize. I end by quoting Ing. Gert Gremmen, in a related posting, Limits for emission are essentially to protect (radio)receivers... I have never met an equipment lacking immunity of any field strength at any frequency within 60 dB above the limits in f.a. CISPR22 that was not a (frequency selective) receiver. That is precisely correct. Ken Javor -- From: cherryclo...@aol.com To: ken.ja...@emccompliance.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 8:45 AM 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 levels of what one could call 'spurious' emissions include EN 61800-3 (industrial drives) and EN 50091-2:1996 (uninterruptible power systems). And I'm not sure whether you would call the leakages from ISM equipment (as defined by CISPR 11) 'spurious'. Is an induction furnace or dielectric heater an intentional transmitter? The semantics of the phrase 'spurious emissions' get very complicated the wider one casts one's net and what one might call the 'spurious emissions' from some ISM equipment can be extremely powerful indeed. But in any case I disagree with your claim that the limited set of possible spurious emissions that you say you concerned with have such low powers that it is impossible for them to only affect radio receivers. I refer again to the airplane compass interference example given in the IEE's guide on EMC and Functional Safety. A compass in an airliner is not a radio receiver, yet this one was interfered with by a laptop computer in the passenger cabin. I don't have many more details on the official investigation into this incident but it might have been that the laptop computer concerned did not comply with Title 47, part 15B of the US Code of Federal Regulations so its spurious emissions were higher than they should have been. On the other hand the passenger cabin is a long way from the pilots instrumentation console so it may be that a similar laptop that did meet Title 47, part 15B of the US Code of Federal Regulations might have caused the same level of interference if it was closer to the compass's electronics. Some electronics are
RE: ICE 601-1 : Insulation between applied part and signal input
Hi, The requirements for insulation between the Applied Part, F-type and the Signal Input part is defined in clause 20.2, part B-d. You need Basic insulation. The working voltage is at a minimum the rated supply voltage. See clause 20.3, paragraph 6. So, assuming 230 Vac input. The requirements are Basic Insulation, Dielectric is 1,500 Vac. Creepage is 4.0 mm, Air Clearance is 2.5 mm. You can use anything the meets these requirements. See also Clause 17.a) for separation requirements. Ned Ned Devine Program Manager III Entela, Inc. 3033 Madison Ave. SE Grand Rapids, MI 49548 616 248 9671 Phone 616 574 9752 Fax ndev...@entela.com e-mail -Original Message- From: Pierre SELVA [mailto:pierre.se...@worldonline.fr] Sent: Thursday, December 27, 2001 4:25 PM To: Forum Safety-emc Subject: IEC 601-1 : Insulation between applied part and signal input Hello from the Franch Alps, I need your help to determinate which insulation is required between an applied part (lin to the OV of the product thru a capacitor) and one signal input in a medical product, against IEC 601-1 requirements. The signal input is connected to the parallel port of a computer. I understand that the insulation has to be a supplementary one. Does this mean that I need to have a galvanic insulation (with optocoupleur, for example) or can I use another system ? Thanks a lot for your contribution. Bonnes fêtes de fin d'année et meilleurs voeux pour 2002 (happy new year and best whishes !) eLABs Pierre SELVA 18 Rue Marceau Leyssieux 38400 SAINT MARTIN D'HERES - FRANCE Phone : 33 (0)6 76 63 02 58 Fax : 33 (0)6 61 37 87 48 e-mail : e.l...@wanadoo.fr mailto:e.l...@wanadoo.fr ps.el...@laposte.net mailto:ps.el...@laposte.net ==
Re: EMC-related safety issues
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 levels of what one could call 'spurious' emissions include EN 61800-3 (industrial drives) and EN 50091-2:1996 (uninterruptible power systems). And I'm not sure whether you would call the leakages from ISM equipment (as defined by CISPR 11) 'spurious'. Is an induction furnace or dielectric heater an intentional transmitter? The semantics of the phrase 'spurious emissions' get very complicated the wider one casts one's net and what one might call the 'spurious emissions' from some ISM equipment can be extremely powerful indeed. But in any case I disagree with your claim that the limited set of possible spurious emissions that you say you concerned with have such low powers that it is impossible for them to only affect radio receivers. I refer again to the airplane compass interference example given in the IEE's guide on EMC and Functional Safety. A compass in an airliner is not a radio receiver, yet this one was interfered with by a laptop computer in the passenger cabin. I don't have many more details on the official investigation into this incident but it might have been that the laptop computer concerned did not comply with Title 47, part 15B of the US Code of Federal Regulations so its spurious emissions were higher than they should have been. On the other hand the passenger cabin is a long way from the pilots instrumentation console so it may be that a similar laptop that did meet Title 47, part 15B of the US Code of Federal Regulations might have caused the same level of interference if it was closer to the compass's electronics. Some electronics are simply very sensitive to demodulation of spurious emissions at specific frequencies, whether by accident or intention of their design or manufacture, so it is impossible to be categorical about their susceptibility to even very low levels of electromagnetic fields. Regards, Keith Armstrong In a message dated 31/12/01 20:47:15 GMT Standard Time, ken.ja...@emccompliance.com writes: Subj:Re: EMC-related safety issues Date:31/12/01 20:47:15 GMT Standard Time From:ken.ja...@emccompliance.com (Ken Javor) To:cherryclo...@aol.com, emc-p...@majordomo.ieee.org In a court of law one must swear to tell the truth, the whole truth, and nothing but the truth. What you stated below is merely part of the truth. The rest of the truth is that spurious emissions emitted by unintentional radiators (the kinds of emissions controlled by CISPR 22 and Title 47, part 15B of the US Code of Federal Regulations) are at such low levels that there is no ability to cause an adverse reaction to anything except a radio receiver. It is only the field intensities associated with intentional rf transmissions that are capable of stimulating electronics operating at higher levels than radio receivers. -- From: cherryclo...@aol.com To: ken.ja...@emccompliance.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Mon, Dec 31, 2001, 12:45 PM Dear Ken Any electromagnetic emissions, whether conducted or radiated, including spurious emissions (however you wish to define the word 'spurious') can be demodulated by the non-linear processes in semiconductors, vacuum tubes, and the like. So the spread of possible problems goes beyond merely preventing the reception of radio communications. I didn't catch the previous correspondence on this issue, but it seems to me that a very narrow definition of the word 'intrinsic' is being used - and this could be misconstrued by
RE: Inquiry of IEC Safety Standard of Antitheft Surveillance Devi ces
We apply IEC950/EN60950/UL1950 to our anti-theft equipment. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Constantin Bolintineanu [mailto:bolin...@dscltd.com] Sent: Friday, December 21, 2001 2:01 PM To: 'Oliver Su'; 'emc.p...@ieee.org' Subject: RE: Inquiry of IEC Safety Standard of Antitheft Surveillance Devi ces Dear Oliver, For the European Market, as per EN50131, the Power supplies for Intruder alarm systems shall comply with the applicable requirements of EN60950, EN60529 (Electrical safety portion). I can not foresee any reason to do not extrapolate this fact to the IEC Standards...60950, 60529. Happy Holidays to all of my VERY PROFESSIONAL COLLEAGUES OF THE MOST PROFESSIONAL AND ELEGANT DISCUSSION GROUP! HAPPY NEW YEAR and HAVE A VERY SAFE AND PROSPEROUS 2002! Respectfully yours, Constantin Constantin Bolintineanu P.Eng. TEPG - DIGITAL SECURITY CONTROLS LTD. 3301 LANGSTAFF Road, L4K 4L2 CONCORD, ONTARIO, CANADA e-mail: bolin...@dscltd.com telephone: 905 760 3000 ext 2568 Visit our web site at www.dscgrp.com -Original Message- From: Oliver Su [mailto:o...@ccsemc.com] Sent: Friday, December 21, 2001 1:26 PM To: 'emc.p...@ieee.org' Subject: Inquiry of IEC Safety Standard of Antitheft Surveillance Devices Hi group, Merry Christmas and Happy New Year! Does anyone know what is IEC Safety Standard of Antitheft Surveillance Device, which is standed at the exit/entrance door of commerical store and department to detect/prevent any merchandise with magnetic piece being stolen. It is wireless and as human's hight, powered by AC120/230V. Best regards, Oliver Su * Oliver Su Compliance Certification Services 561 F Monterey Morgan Hill, CA 95037-9001, USA Tel: (408) 463-0885 x 109 fax: (408) 463-0888 E-mail: o...@ccsemc.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://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.
Type Approval for US Coast Guard
Hi all, Any people in this perfect discussion forum who have experience with the USCG Type Approval programme for Fire Detection systems ? Please take contact. 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: 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: Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about Spectrum Analyzer
I read in !emc-pstc that Wan Juang Foo f...@np.edu.sg wrote (in of9079e07a.37ec5220-on48256b35.0025a...@np.edu.sg) about 'Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about Spectrum Analyzer', on Wed, 2 Jan 2002: [big snip] To all forum readers, This got me interested and I am looking for a very old conference paper on this subject. Can anyone on this forum help? Nano,E. Correction Factors for Quasi-Peak Measurements with Spectrum Analyzer. 1975 International EMC Conference Record, Montreaux, pp. 156-161. sincerely, Tim Foo I will pass on your enquiry to Professor Nano, suggesting that he contacts you directly. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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: Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about SpectrumAnalyzer
Tim Foo Thanks for your information. There are not many books about SA, except by Engelson Morris and another one by Mr. White. The Modern does have a good chapter about filter bandwidth for different kinds of signal. Best Regards KC Chan Wan Juang Foo f...@np.edu.sg 01/02/02 03:14pm KC, I suppose you have read CR Paul's section on this topic. I had a quick filp through and the two books that you mention in the materials is indeed aged. I recomend that you read Tim Williams's and Tihanyi's section on this topic of detectors. 1.EMC for systems and installations / Tim Williams Keith Armstrong. Oxford : Newnes, 2000. 2.EMC for product designers / Tim Williams. 3rd ed. Oxford : Newnes, 2001 3.Electromagnetic compatibility in power electronics / Laszlo Tihanyi. New York : IEEE Press, c1995. 4.Introduction to electromagnetic compatibility / Clayton R. Paul. New York : Wiley, c1992. Series: Wiley series in microwave and optical engineering To all forum readers, This got me interested and I am looking for a very old conference paper on this subject. Can anyone on this forum help? Nano,E. Correction Factors for Quasi-Peak Measurements with Spectrum Analyzer. 1975 International EMC Conference Record, Montreaux, pp. 156-161. sincerely, Tim Foo KC CHAN [PDD] kcc...@hkpc.org 01/02/02 08:52 AM Tim Foo Actually I am looking for something about the VBW setting and how it affects the measurement. I got feedback from the group that the setting of the Spectrum Analyzer (SA) shall be at linear mode instead of logarithmic mode, I understand the explanation from the group, but I do find at least on EMC standard (CISPR 11), it does require to use logarithmic mode for average measurement by setting VBW at 10 Hz. It got confusion on that. Besides, I want to know more about the detectors, how it affects the measurement and the details of the construction. I was able to get one from the local University for the first one (Modern...), there is nothing about the detectors. Best Regards KC Chan Wan Juang Foo f...@np.edu.sg 01/02/02 08:14 AM KC, I suppose you meant the other newer book: Modern spectrum analyzer theory and applications / Morris Engelson. Dedham, Mass. : Artech House, c1984. My library have both copies, I can pop around the corner to take a look at it. What kind of comments are you specifically looking for? Tim Foo KC CHAN [PDD] kcc...@hkpc.org 12/24/01 11:25 AM Hi all I would like to seek comment about these two books. Modern Spectrum Analyzer Theory and Applications / Morris E. Modern Spectrum Analyzer Measurements I encountered these two titles from Internet when I looked for spectrum analyzer related materials. Best 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: 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.
Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about Spectrum Analyzer
KC, I suppose you have read CR Paul's section on this topic. I had a quick filp through and the two books that you mention in the materials is indeed aged. I recomend that you read Tim Williams's and Tihanyi's section on this topic of detectors. 1.EMC for systems and installations / Tim Williams Keith Armstrong. Oxford : Newnes, 2000. 2.EMC for product designers / Tim Williams. 3rd ed. Oxford : Newnes, 2001 3.Electromagnetic compatibility in power electronics / Laszlo Tihanyi. New York : IEEE Press, c1995. 4.Introduction to electromagnetic compatibility / Clayton R. Paul. New York : Wiley, c1992. Series: Wiley series in microwave and optical engineering To all forum readers, This got me interested and I am looking for a very old conference paper on this subject. Can anyone on this forum help? Nano,E. Correction Factors for Quasi-Peak Measurements with Spectrum Analyzer. 1975 International EMC Conference Record, Montreaux, pp. 156-161. sincerely, Tim Foo KC CHAN [PDD] kcc...@hkpc.org 01/02/02 08:52 AM Tim Foo Actually I am looking for something about the VBW setting and how it affects the measurement. I got feedback from the group that the setting of the Spectrum Analyzer (SA) shall be at linear mode instead of logarithmic mode, I understand the explanation from the group, but I do find at least on EMC standard (CISPR 11), it does require to use logarithmic mode for average measurement by setting VBW at 10 Hz. It got confusion on that. Besides, I want to know more about the detectors, how it affects the measurement and the details of the construction. I was able to get one from the local University for the first one (Modern...), there is nothing about the detectors. Best Regards KC Chan Wan Juang Foo f...@np.edu.sg 01/02/02 08:14 AM KC, I suppose you meant the other newer book: Modern spectrum analyzer theory and applications / Morris Engelson. Dedham, Mass. : Artech House, c1984. My library have both copies, I can pop around the corner to take a look at it. What kind of comments are you specifically looking for? Tim Foo KC CHAN [PDD] kcc...@hkpc.org 12/24/01 11:25 AM Hi all I would like to seek comment about these two books. Modern Spectrum Analyzer Theory and Applications / Morris E. Modern Spectrum Analyzer Measurements I encountered these two titles from Internet when I looked for spectrum analyzer related materials. Best 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: 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: Microwave Cable assembly
http://www.goreelectronics.com/products/cable_assemblies/micro_test.cfm KC CHAN [PDD] wrote: Hi all I am looking for a K-type connector cable that is for measurement up to 26.5 GHz, any recommendation of the suppliers? Try http://www.goreelectronics.com/products/cable_assemblies/micro_test.cfm. You can dowload a catalog covering your requirements. Keep in mind that all coax is extremely lossie at Ku band and correction factors must be used for measurements. Fred Townsend By the way, does anyone know that if Horn antenna up to 40 GHz with SMA or N-type connector available in the market? Such a high frequency range, I think SMA or N-type might not be suitable choices. Thank You 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: 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.
Microwave Cable assembly
Hi all I am looking for a K-type connector cable that is for measurement up to 26.5 GHz, any recommendation of the suppliers? By the way, does anyone know that if Horn antenna up to 40 GHz with SMA or N-type connector available in the market? Such a high frequency range, I think SMA or N-type might not be suitable choices. Thank You 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: 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: EMC-related safety issues
Navigation aids are radios. They are designed to have these sensitivities. The balance of the suite of avionics have their RE controlled to protect these radios. It all works. If an on-board rfi source such as a portable CD player or laptop interferes with the operation, this is not a catastrophic issue because the pilot, seeing a sudden change in position relative to the runway, and not having felt any accompanying acceleration would immediately deduce his instrumentation was malfunctioning and take appropriate steps. It is only when the navigational aids are tied to the auto-pilot and the auto-pilot doesn't have the intelligence to discern an impossible reading from the navigation aid that the potential for immediate catastrophe looms. This was the case with the DC-10 that is the origin of the rule to turn off personal electronics on take-off and landing. In the case of the DC-10, the pilot seized control from the auto-pilot and redirected the aircraft towards its former heading. Since this was on final approach, it was a fairly narrow escape. -- From: John Woodgate j...@jmwa.demon.co.uk To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Tue, Jan 1, 2002, 1:54 PM I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in 20020101193617.STGC6581.femail3.sdc1.sfba.home.com@[65.11.150.27]) about 'EMC-related safety issues', on Tue, 1 Jan 2002: The standard navigational aids: ILS, TACAN and VOR all have simple modulation schemes. ILS receivers have sensitivities on the order of -90 dBm, TACAN is -80 dBm, glide slope -60 dBm and marker beacon -50 dBm. Yes, that's what I had in mind. Surprisingly vulnerable. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- 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: Books about Spectrum Analyzer
Tim Foo Actually I am looking for something about the VBW setting and how it affects the measurement. I got feedback from the group that the setting of the Spectrum Analyzer (SA) shall be at linear mode instead of logarithmic mode, I understand the explanation from the group, but I do find at least on EMC standard (CISPR 11), it does require to use logarithmic mode for average measurement by setting VBW at 10 Hz. It got confusion on that. Besides, I want to know more about the detectors, how it affects the measurement and the details of the construction. I was able to get one from the local University for the first one (Modern...), there is nothing about the detectors. Best Regards KC Chan Wan Juang Foo f...@np.edu.sg 01/02/02 08:14am KC, I suppose you meant the other newer book: Modern spectrum analyzer theory and applications / Morris Engelson. Dedham, Mass. : Artech House, c1984. My library have both copies, I can pop around the corner to take a look at it. What kind of comments are you specifically looking for? Tim Foo KC CHAN [PDD] kcc...@hkpc.org 12/24/01 11:25 AM Hi all I would like to seek comment about these two books. Modern Spectrum Analyzer Theory and Applications / Morris E. Modern Spectrum Analyzer Measurements I encountered these two titles from Internet when I looked for spectrum analyzer related materials. Best 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: 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: Books about Spectrum Analyzer
KC, I suppose you meant the other newer book: Modern spectrum analyzer theory and applications / Morris Engelson. Dedham, Mass. : Artech House, c1984. My library have both copies, I can pop around the corner to take a look at it. What kind of comments are you specifically looking for? Tim Foo KC CHAN [PDD] kcc...@hkpc.org 12/24/01 11:25 AM Hi all I would like to seek comment about these two books. Modern Spectrum Analyzer Theory and Applications / Morris E. Modern Spectrum Analyzer Measurements I encountered these two titles from Internet when I looked for spectrum analyzer related materials. Best 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: 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.
