Re: EMC-related safety issues
Cortland Richmond wrote: AIrbag testing? Well, since it costs about $US 1500 to replace them (here), I suppose there WOULD be a price hike! A couple of kids were caught by the police in a parking lot. Seems the fun thing to do to people's cars was to walk around the parking lot with baseball bats and bang on the front bumper causing the air bags to activate. Can't imagine what that all cost. - 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.
Re: EMC-related safety issues
RE: EMC-related safety issuesKyle Ehler wrote: Another point of trivia is that a fresh oil change and new air filter prior to having your vehicle smog tested will improve the emissions results. At one time there was available OTC a fuel additive that one could deploy to further skew the results in your favor. I knew a guy who drilled a small hole in the side of his carborator, attatched a hose setup that you would use for an acquirium the other end of which was put into a water bottle. While the car was in idle, he'd adjust a valve on the hose to a slow drip of water into the carborator. This setup was on an old truck of his and he always got terrifically low emissions readings. - 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.
Re: Demodulating RF
I read in !emc-pstc that Gelfand, David david.gelf...@ca.kontron.com wrote (in DAE684A26044B6469EF0A1E1565116820F0B63@semsl131) about 'Demodulating RF', on Fri, 4 Jan 2002: This is very interesting. I had a terrible battle with rf conducted immunity. Could you describe your experiment? Well, it could be said to be very crude. I made a 20 dB gain amplifier on a scrap of board, and monitored the audio output produced by an r.f. signal modulated at 1 kHz. This signal was applied to a very small parallel-plate apparatus with plates only 75 mm wide by 120 mm long, separated by 75 mm. The coaxial feeder to this was simply terminated in 50 ohms at the plates, and the amplifier was supported roughly in the centre of the working volume. Since the apparatus is so small, the field strength within it should be reasonably predictable, even at 1 GHz. But what I did was to compare the signal generator outputs required to produce a fixed 1 kHz output voltage from the two amplifiers, one with a 724 and one with an 072 op-amp, so the actual field strength had little effect on the results. The difference was fairly constant at approximately 26 dB, irrespective of frequency and field strength, up to about an estimated 3 V/m. Above that, the difference decreased a little. -- 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: North America Voltage Ratings
OK, I have to ask. Wouldn't it be acceptable to state 120V and with the +- 10% you would have an implied range of 108-132V? Rick Busche rbus...@es.com -Original Message- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: Friday, January 04, 2002 2:42 PM To: cecil.gitt...@kodak.com Cc: emc-p...@majordomo.ieee.org Subject: North America Voltage Ratings Cecil, This site http://www.panelcomponents.com/guide.htm lists U.S. and Canada as 120V and Mexico as 127V. We normally rate our printers as 110-127V, if not going to Japan. However, I have seen single value ratings of 115V and 120V on models going to these countries without issues brought to my attention. My suggestion is 110-127V. George cecil.gittens%kodak@interlock.lexmark.com on 01/04/2002 04:04:37 PM Please respond to cecil.gittens%kodak@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: From: Cecil A. Gittens Hi All, What is the correct voltage labeling for the US, Canada and Mexico on product dataplate? Is it 100-120V or 100-127V? --- 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
Sorry Rich, I support John's statement about the 3 meters separation distance. After all, you're in control in your own sleeping room. BTW listening radio in the dark is an enlightening experience. If it were your neighbour sleeping that close to your lamp this would have given rise to discussion between you or worse . (if he understood the cause of the interference) Govenrment regulations were not there to prevent interference under all circumstances, just to regulate the number of complaints that might give rise to legal issues. Or would you sue yourself for operating your bedlamp so close to your AM radio ;))) I suggest you reinsert your old filament bulb or buy a receiver with external antenna (but keep it away from your neighnours bedlamp ;)) Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Rich Nute Sent: Thursday, January 03, 2002 10:09 PM To: j...@jmwa.demon.co.uk Cc: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Hi John: I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. Limits in the household environment are based on a 3 m separation between source and receiver. Wonderful! Either the lamp or the radio must be on the opposite side of the room from my bedside table. When I am in bed, one or the other is not controllable, and is therefore useless to me. Whine mode on: I want both on my bedside table, and I want both to do all of their functions. This IS not the usage contemplated by 3 m separation EMC requirements. :-) Best wishes for the New Year, Rich --- 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. attachment: Gert Gremmen.vcf
North America Voltage Ratings
Cecil, This site http://www.panelcomponents.com/guide.htm lists U.S. and Canada as 120V and Mexico as 127V. We normally rate our printers as 110-127V, if not going to Japan. However, I have seen single value ratings of 115V and 120V on models going to these countries without issues brought to my attention. My suggestion is 110-127V. George cecil.gittens%kodak@interlock.lexmark.com on 01/04/2002 04:04:37 PM Please respond to cecil.gittens%kodak@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: From: Cecil A. Gittens Hi All, What is the correct voltage labeling for the US, Canada and Mexico on product dataplate? Is it 100-120V or 100-127V? --- 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.
Demodulating RF
This is very interesting. I had a terrible battle with rf conducted immunity. Could you describe your experiment? Best regards, David. David Gelfand Regulatory Approvals Kontron Communications Montreal Canada -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, January 04, 2002 12:00 PM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I read in !emc-pstc that cherryclo...@aol.com wrote (in 17d.1b28bc2.296 70...@aol.com) about 'EMC-related safety issues', on Fri, 4 Jan 2002: Does anyone else think that ordinary semiconductors doesn't respond to RF? Your experience has been shared by thousands. The demodulation normally occurs at the first semiconductor junction that the r.f signal 'sees', although at 10 V/m there may be propagation effects. The faulty reasoning that makes this effect surprising is 'silicon diodes and transistors need 0.6 V forward bias in order to conduct'. It isn't TRUE! If you add 'more than a few microamps' it's less untrue. But conduction occurs right down to minute signal voltages, resulting, certainly, in even more minute currents, but current enough to cause trouble. 'Underbiased' junctions act as excellent square-law detectors; for every 1 dB increase in input signal level you get 2 dB increase in level of recovered modulation. You may well find that JFET-input op-amps are far less sensitive to r.f. A test that I carried out a while back, on a very simple board with no EMC counter-measures at all, indicated a 26 dB difference between an LM324 and a TL072, the difference being substantially independent of frequency from 150 kHz to 1 GHz. -- 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.
[no subject]
From: Cecil A. Gittens Hi All, What is the correct voltage labeling for the US, Canada and Mexico on product dataplate? Is it 100-120V or 100-127V? --- 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 agree - ALL semiconductor demodulate. If they did not then there would be NO distortion in amplifiers and most of the HiFi industry would be out of business. Demodulation is only part of the problem however. Consider a semiconductor switching a relay. The semiconductor may switch the relay due to external EMC - but it is more likely that the semiconductor or the relay will fail and produce an 'unsafe' output. I spent 6 months designing a fail-safe synchronous gating circuit and 3 months writing the patent so Please don't tell me that it is impossible to design a safe circuit. In my experience (20 years of RD) spurious EMC/safety issues are mostly due to poor design, in the first place, and then inadequate testing. EXAMPLE from the last 10 years - when the 5Volt PSU for a safety circuit was disconnected, the system was ARMED. This was discover just before the product went into production and after through(sic) testing. Best regards Gregg PLEASE NOTE NEW NUMBERS P.O. Box 310, Reedville, Virginia 22539 USA Phone: (804) 453-3141 Fax: (804) 453-9039 Web: www.test4safety.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Cortland Richmond Sent: Friday, January 04, 2002 12:54 PM To: cherryclo...@aol.com Cc: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I don't believe this is what people are saying here. What they are saying is, ordinary semiconductors won't demodulate RF levels produced by an unintentional radiator. Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) cherryclo...@aol.com wrote: Does anyone else think that ordinary semiconductors doesn't respond to RF? I have tested a product which was little more than an LM324 quad op-amp for RF immunity using IEC 61000-4-3. This op-amp has a slew rate of 1V/micro-second on a good day with the wind in its favour. It was housed in an unshielded plastic enclosure. Demodulated noise that exceeded the (not very tough) product specification were seen all the way up to 500MHz at a number of spot frequencies that appeared to be due to the natural resonances of the input and output cables. --- 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 Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Lasting of the CE marking
I am not sure but from what you say you seem to have missed the point that in most directives, certainly the EMC and LVD it is the individual item that must meet the current standards at the time that item is placed on the market in the EEA or taken into service there for the first time. It is irrelevant when the design was first marketed. If you have tested the design and haven't changed it and the standards you tested the design to are still current. you may carry on marketing copies of that design. When a standard is withdrawn, from that date you may not sell such items until you can show the design meets the new standards Nick Rouse - Original Message - From: Kim Boll Jensen kimb...@post7.tele.dk To: EMC-PSTC emc-p...@majordomo.ieee.org Sent: Thursday, January 03, 2002 8:54 PM Subject: Lasting of the CE marking Hi all I was just seeking through EMC LVD RTTE and MD directives for evidence of my interpretation but I couldn't find it, so can some of you help me. As I recall there are the following rules: For EMC directive you will always have to produce according to the latest harmonized standards (after dow date) For all other directives you just use the harmonized standards which was acceptable at the time of entry to the market (then you can produce the same product for decades without retesting to new harmonized standards) Please help me finding the clauses in the directives which supports this statement. But what about RTTE when new standards are harmonized where no standards was before ? Best regards, Kim Boll Jensen Bolls Raadgivning --- 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.
Automotive Safety
The original thread began as a question about the duration of a manufacturer's obligation to guarantee EMC-related automotive equipment. I had tossed in the suggestion that maybe the manufacturer was obligated in a way similar to Federal fuel emission control equipment. Maybe not correct, but an interesting approach to explore. I first looked at the National Transportation Safety Board's site, finding a wonderfully complex missive for Manufacturers of motor vehicles at: http://www.nhtsa.dot.gov/cars/rules/maninfo/newmanufacturer.pdf Bumpers, glazing, rims, brake hoses; the compliance list flows on and on. And it all points back to Title 49 CFR. Now, let's look at the Environmental Protection Agency's Office of Air and Radiation and the Office of Transportation and Air Quality site at: http://www.epa.gov/otaq/transp/traqconf.htm This gives us a look down the rabbit-hole of the Transportation Control Measures Conformity Issues. And now notice that another couple of agencies are helping us; the Federal Highway Administration and the Federal Transit Administration. If I wasn't already completely glazed over, I might follow up on such gems as: Federal Register Supplemental Notice of Proposed Rule http://www.epa.gov/fedrgstr/EPAFR-CONTENTS/2000/July/Day-28/contents.htm: Motor Vehicle Emissions Budgets in Attainment Demonstrations for the One-Hour National Ambient Air Quality Standard for Ozone. OK, I'll admit it. They win. I'm going home to hide. Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- 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: SMPS Derating reqs for Altitude range of 5000-10000ft
Hi Chris, Andrew, Carmen: With regard to safety, both effects of altitude must be considered: 1) effect of air pressure on the electric strength of air (clearance), and 2) effect of lower density air on the temperature of solid insulation. (Creepage is a surface degradation phenomenon that is solely a function of working voltage, and is independent of altitude. But, creepage can never be less than the parallel clearance, so the creepage may also be affected for those situations where the minimum clearance is greater than the allowed creepage.) Best wishes for the New Year, Rich --- 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.
ANSI C63.4 - Annex M
Hello, I just got hold of a copy of ANSI C63.4-2000 annex M. Does anyone have experience using the Table M1.1 spreadsheet? Some of the equations look wrong to me. It is probably my ignorance, but I could get lucky. :) For example: You have 2 arrays of frequencies and field strength readings in uV/m. To calculate the difference in dB ANSI gives 20*log(value1/value2). Where value one and value 2 are two array elements. This is performed element by element on the array to create a third array. This third array is in dB. To take the mean of this array ANSI give this equation: 20*log(1/n*SUM(array3)) It strikes me as odd that I am taking the logarithm of a logarithm to get to the mean of the first array. Thanks, Mat Aschenberg --- 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: SMPS Derating reqs for Altitude range of 5000-10000ft
I agree that creepage and clearance distances change. However, I'm not sure if you can answer that it is not a power issue. If the power supply depends on air for cooling; wouldn't the less dense air at higher altitudes be less effective at cooling the supply? A rough guess (admittedly thought up as I'm typing this message) would be that the cooling effectiveness of air would vary proportionally with air density. A furthur stretch of that reasoning would lead me to believe that the power ratings of forced air cooled supplies would also vary with air density. It may not vary with one to one correspondence due to the fact that there are other cooling mechanisms such as radiative cooling which can occur without air. As altidude goes up, air density goes down. Wouldn't cooling effectiveness also go down leading to a slightly lower power rating for air cooled supplies? Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | -Original Message- From: Andrew Carson [SMTP:acar...@uk.xyratex.com] Sent: Friday, January 04, 2002 12:59 PM To: Carmen.Filimon Cc: EMC Forum Subject: Re: SMPS Derating reqs for Altitude range of 5000-1ft Carmen If your power supply is approved to IEC60950, then normally it will be approved upto 2000m. Above this altitude the required creepage and clearance distances start to increase. It is an electrical insulation issue, not a thermal issue. Carmen.Filimon wrote: Hi All I'm trying to find out what the specified operational altitude range(s) is (are) for power supplies (particularly switching mode ones). Do any of you know what that spec may be, and particularly what is the rule for derating at altitude for thermal issues. Many manufacturers don't specify a maximum altitude but instead design in enough thermal overhead to accommodate any reasonable terrestrial location. According to GR-63-CORE the operating range without derating is 1800m above sea level. If derating is required above 1800m then the manufacturer must specify any additional requirements. Is it a safety derating factor so that customers at 5000-1ft don't smell smoke? Do we have any recommendations for derating the operational temperature / power consumption of power supplies as the operational altitude increases? Any information or ideas you have would be appreciated. Regards, Carmen Filimon Leitch Canada --- 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. -- Andrew Carson - Senior Compliance Engineer, Xyratex, UK Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 --- 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:
Re: EMC-related safety issues
I read in !emc-pstc that Cortland Richmond cortland.richm...@alcatel.co m wrote (in 3c35ec35.5d1a...@alcatel.com) about 'EMC-related safety issues', on Fri, 4 Jan 2002: I don't believe this is what people are saying here. What they are saying is, ordinary semiconductors won't demodulate RF levels produced by an unintentional radiator. Oh, is THAT what the message meant? There's not much comparison between 10 V/m or even 3 V/m and the permitted emission levels of around 1 mV/m! -- 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: SMPS Derating reqs for Altitude range of 5000-10000ft
Actually, it is both. The decreasing density of air results in a lower voltage withstand and a lower rate of convection cooling.. IEC 60950 only addresses the safety aspect of the change, not the operational aspects. acar...@uk.xyratex.com (Andrew Carson)@majordomo.ieee.org on 01/04/2002 11:59:15 AM Please respond to acar...@uk.xyratex.com (Andrew Carson) Sent by: owner-emc-p...@majordomo.ieee.org To: Carmen.Filimon carmen.fili...@leitch.com cc: EMC Forum emc-p...@ieee.org Subject: Re: SMPS Derating reqs for Altitude range of 5000-1ft Carmen If your power supply is approved to IEC60950, then normally it will be approved upto 2000m. Above this altitude the required creepage and clearance distances start to increase. It is an electrical insulation issue, not a thermal issue. Carmen.Filimon wrote: Hi All I'm trying to find out what the specified operational altitude range(s) is (are) for power supplies (particularly switching mode ones). Do any of you know what that spec may be, and particularly what is the rule for derating at altitude for thermal issues. Many manufacturers don't specify a maximum altitude but instead design in enough thermal overhead to accommodate any reasonable terrestrial location. According to GR-63-CORE the operating range without derating is 1800m above sea level. If derating is required above 1800m then the manufacturer must specify any additional requirements. Is it a safety derating factor so that customers at 5000-1ft don't smell smoke? Do we have any recommendations for derating the operational temperature / power consumption of power supplies as the operational altitude increases? Any information or ideas you have would be appreciated. Regards, Carmen Filimon Leitch Canada --- 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. -- Andrew Carson - Senior Compliance Engineer, Xyratex, UK Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 --- 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
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200201041623.iaa13...@epgc264.sdd.hp.com) about 'EMC-related safety issues', on Fri, 4 Jan 2002: So, I am acting unreasonably by using a CFL and a radio on my bedside table. If we're being very meticulous, it is not unreasonable to use a CFL next to a radio, but it IS unreasonable to complain about what happens! Is there another solution? Further reducing the emissions is simply too costly, and is bad economics anyway, since all the mitigation components, probably still in good working order, are thrown away when the lamp fails (usually the filter capacitor in the d.c. supply dries out). -- 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
Ghery: Every couple of years, I rise to the level of personal expert, as I endure the local bi-annual vehicle smog inspection. Two days ago, I had my 1974 Chevy Nova tested. (It passed, as usual, with measured emissions at 3% to 10% of allowable limits, but I had to buy a new gas tank cap.) They check the hydrocarbon, carbon monoxide and nitrogen oxide emission levels. They look to be sure you still have all your Federally required emission systems. They check the function of engine systems like the PC valve, the exhaust gas valve and the ignition timing. Testing is performed on a dynamometer, at low high speed. They even take off your gas tank cap and make sure it holds a vacuum. The rules are a labyrinth. California does smog checks on 1974 and newer models only. Unless your car is new, or up to a few (?) years old, and then you are also exempt. Not every county in California requires the smog checks. And in counties which do require the testing, some parts of counties are exempt. I live in El Cajon in San Diego county, but if I had a legal address in Julian (same county, just about 40 miles away) I would be exempt. (It's interesting that Julian has a huge population that uses PO boxes and never seems to be in town.) When your car is from the 70's, you periodically are notified that you are a gross polluter and have to get your smog check done at a special test only station. (This type of test station is supposed to be more honest, since they are prohibited from providing any repairs, or even advice on your car's condition, other than handing you the computer print-out.) The whole test takes about 30 minutes, with almost everything under computer control. Newer cars, with on-board computers, are being tested by connecting the station computer to the vehicle's data port. Makes you wonder how much information about your driving habits and maintenance is being stored in your car's computer. Maybe the DMV will soon be able to download speed and acceleration data. Maybe you can get a moving violation from pulling too many g's (higher gas consumption, higher emissions) or exceeding 65 MPH (maybe billed like power, in increments of MPH-minutes). Maybe ignoring your check engine idiot light will become a DMV felony. The ultimate step will be to equip your on-board computer with a short-range data link. Then, periodic roadway sensors can determine if you are allowed to drive under current conditions. You might be given an option to slow to 42 MPH maximum, or pay a speed surcharge, or halt until 10 PM when smog control limits relax. I'm thinking about moving to Julian. Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Friday, January 04, 2002 8:28 AM To: 'James, Chris'; 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group Subject: RE: EMC-related safety issues Chris, Annual inspections of motor vehicles are done on a state by state basis, rather than as a national requirement in the U.S. Automobiles are registered at the state level, so the federal government doesn't get involved. Some states have annual inspections, others don't. Likewise, smog inspections are at a state or lower level. California cars get smogged. Here in Washington it depends on what county you live in. If air quality in your county is good enough, you don't have to have your car smogged. If not, you get to pay more for the privilege of having a car. I live in a county where I don't have to deal with the fight. BTW, a trick I learned when I lived in California is that you stand a much better chance of passing the smog test if the engine is well warmed up when you arrive at the inspection station. Take it for what it's worth. Be thankful that we don't have to have annual inspections on our cars to the extent that one does on an airplane... $$$ Ghery Pettit Intel -Original Message- From: James, Chris [mailto:c...@dolby.co.uk] Sent: Friday, January 04, 2002 1:02 AM To: 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group Subject: RE: EMC-related safety issues Sorry disagree about turn and brake lights not being in the same class. Their very failure is often the reason for very serious accidents. I have long wished that all car manufacturers had to by law fit bulb failure warning devices to cars (but what happens when that fails). In the UK it is an offence to drive a vehicle with defective lights, (although many do). It is the driver's (not owner's) obligation to be satisfied the vehicle they are driving is fit to be on the road irespective of whether it passed it's MOT the previous day. The UK mandatory annual vehicle inspection (MOT) for vehicles over 3 years old, covers seat belts, brake efficiency on a
RE: EMC-related safety issues
In Kansas there are no emissions laws or annual inspections. The entire state gets a full air change every 10 minutes -so why bother? We also benefit from no mandated vehicle inspections -ever. The only thing that does get a check is the odometer and VIN, but only when a title transfer occurs. The state is more interested in indentity than safety of the machines the public chooses to play caroms with. IIRC, California and many states have an amendment to their respective emissions law that states that once a car is more than XX years old, they are considered 'antique' and exempt from the law. The threshold ranges from 20 to 30 years, depending on state/county. Another point of trivia is that a fresh oil change and new air filter prior to having your vehicle smog tested will improve the emissions results. At one time there was available OTC a fuel additive that one could deploy to further skew the results in your favor. Kyle Ehler '73 and '76 914 2.0 'Euro' antiques -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Friday, January 04, 2002 10:28 AM To: 'James, Chris'; 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group Subject: RE: EMC-related safety issues Chris, Annual inspections of motor vehicles are done on a state by state basis, rather than as a national requirement in the U.S. Automobiles are registered at the state level, so the federal government doesn't get involved. Some states have annual inspections, others don't. Likewise, smog inspections are at a state or lower level. California cars get smogged. Here in Washington it depends on what county you live in. If air quality in your county is good enough, you don't have to have your car smogged. If not, you get to pay more for the privilege of having a car. I live in a county where I don't have to deal with the fight. BTW, a trick I learned when I lived in California is that you stand a much better chance of passing the smog test if the engine is well warmed up when you arrive at the inspection station. Take it for what it's worth. Be thankful that we don't have to have annual inspections on our cars to the extent that one does on an airplane... $$$ Ghery Pettit Intel -Original Message- From: James, Chris [mailto:c...@dolby.co.uk] Sent: Friday, January 04, 2002 1:02 AM To: 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group Subject: RE: EMC-related safety issues Sorry disagree about turn and brake lights not being in the same class. Their very failure is often the reason for very serious accidents. I have long wished that all car manufacturers had to by law fit bulb failure warning devices to cars (but what happens when that fails). In the UK it is an offence to drive a vehicle with defective lights, (although many do). It is the driver's (not owner's) obligation to be satisfied the vehicle they are driving is fit to be on the road irespective of whether it passed it's MOT the previous day. The UK mandatory annual vehicle inspection (MOT) for vehicles over 3 years old, covers seat belts, brake efficiency on a rolling road, mirrors, windshield cracks (a 20mm, 3/4inch crack in the wrong place will fail a vehicle), tyres, wheel bearings, gaiters, steering components, structural body condition, lights, smog emissions, etcI don't believe airbags are tested but guess it will come, along with the inevitable hike in price. I'm surprised the US does not have a similar Federal requirement - with all the vehicles this is a cash cow waiting to be milked. Chris -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: 04 January 2002 02:40 To: Doug McKean; EMC-PSTC Discussion Group Subject: Re: EMC-related safety issues A signal light is easily replaceable in terms of time and money. Most people don't use them (well, in good old Huntsville, AL, anyway, where a favorite bumper sticker reads, Turn signals, not just for smart people anymore). Failure of a light is not in the same class as an airbag deploying at the wrong time or not deploying, or ditto for brakes. -- From: Doug McKean dmck...@auspex.com To: EMC-PSTC Discussion Group emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 7:00 PM Point taken Ken, but consider signal lights. They're essentially safety devices and they're supposed to be maintained on cars which have been transferred amongst several owners and are decades old. Same idea with windshields, I guess also. - 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:
Standards in Brazil
Greetings, I am curious to know if anyone can tell me which standard (norm) in Brazil is equivalent to IEC 1010-1? Also, does anyone know if this as yet unnamed standard is covered by a mutual recognition agreement? I've tried the Comitê Brasileiro de Eletricidade website but as you might expect it's all in Portuguese. I cannot find an English version and translation tools are pretty deficient. Best regards to all in 2002, -doug --- Douglas E. Powell, Compliance Engineer Advanced Energy Industries, Inc. Mail stop: 203024 1626 Sharp Point Drive Ft. Collins, CO 80525 970.407.6410 (phone) 970-407.5410 (fax) mailto:doug.pow...@aei.com --- _ This message, including any attachments, may contain information that is confidential and proprietary information of Advanced Energy Industries, Inc. The dissemination, distribution, use or copying of this message or any of its attachments is strictly prohibited without the express written consent of Advanced Energy Industries, Inc. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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
At 8:34 AM -0500 1/4/2002, Keith Armstrong wrote: Does anyone else think that ordinary semiconductors doesn't respond to RF? I agree that commonly used semiconductors have responses well into the 100's of MHz. How much of a problem this is will depend on the nature and function of the circuitry using these components. The EUT wires, cables, pcb traces etc. act like antennae, on which the incident field voltages and currents. An antenna factor can be thought of as ratio of the field strength to the voltage induced on the terminated cable connected to the antenna. In an impedance matched system, AF=9.734/lamda*(G)^0.5, lamda being wavelength in meters, G being antenna gain over isotropic, or in dB AF dB = - G dBi -29.7 dB + 20logFMHz Assuming G is 1 (isotropic antenna), AF is 1 (= 0 dB) at about 30.8 MHz, and AF get larger as frequency increases, to a factor of 32.7 (= 30.3 dB) at 1 GHz . Since AF is field strength divided by induced voltage, the voltage induced on the trace goes down as frequency goes up for the same incident field strength. An effective receive antenna needs to be on the order of 1/2 wavelength or so; for 30 MHz this is 15m, for 1000 MHz this is 15 cm. So if a victim EUT circuit has a pretty effective receive antenna, and does not have any filtering and is equally sensitive across the frequency range under consideration (all taken together, a worst case scenario for susceptibility), (1) A 10 V/m field will theoretically induce a voltage 0.33V to 10V, depending on frequency (2) A 5000 uV/m field (10x the FCC class B limit above 960 MHz) will theoretically induce a voltage from 152 uV to 5 mV, depending on frequency. (3) A 500 uV/m field will theoretically induce a voltage from 15 uV to 500 uV depending on frequency. These are first order approximations, but they are useful in determining the level of the potential EMI threat. For instance a 4-30 mA sensor circuit using high gain operational amps will most likely be interfered with in scenario (1), there may be some susceptibility detected in scenario (2), and most likely no problem encountered with scenario (3). A sensitive all - band AM communications receiver will have problems with all three, a broadcast TV operating in a strong signal area will probably be OK with scenario 3 but not with 1 or 2. I guess what I'm really trying to say with all this is that EMC is a systems thing, taking into account the nature of the culprit EMI generator, the nature of the victim EMI receiver, and the path between them. Then we have the economics of operating different devices in the same vicinity, the politics of who gets how much of what kind of protection, etc., etc. All things considered, we should have jobs for life! best regards and a Happy New Year to all. Tom Cokenias T.N. Cokenias Consulting P.O. Box 1086 El Granada CA 94018 tel 650 726 1263 cell 650 302 0887 fax 650 726 1252
Car Radio question resolved!!
Hi All, I just thought I would update you all on the resolution to my problem. It turns out that, due to the fact that I have the antenna in the glass, there is a booster that needed to be connected. Once connected - bingo - all works fine. _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx --- 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: SMPS Derating reqs for Altitude range of 5000-10000ft
From the Paschen curve, the electrical spacings must be increased 14% at 3000 meters over those at 2000 meters. Thermal derating is a tougher call since some smps vendors engineer in more cooling capacity than others. Testing for your application is the only reliable way to make a good determination if the manufacturer does not specify a derating curve. Daniel E. Teninty, P.E. Managing Partner DTEC Associates LLC Streamlining The Compliance Process Advancing New Products To Market http://www.dtec-associates.com (509) 443-0215 (509) 443-0181 fax -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Carmen.Filimon Sent: Friday, January 04, 2002 8:28 AM To: EMC Forum Subject: SMPS Derating reqs for Altitude range of 5000-1ft Hi All I'm trying to find out what the specified operational altitude range(s) is (are) for power supplies (particularly switching mode ones). Do any of you know what that spec may be, and particularly what is the rule for derating at altitude for thermal issues. Many manufacturers don't specify a maximum altitude but instead design in enough thermal overhead to accommodate any reasonable terrestrial location. According to GR-63-CORE the operating range without derating is 1800m above sea level. If derating is required above 1800m then the manufacturer must specify any additional requirements. Is it a safety derating factor so that customers at 5000-1ft don't smell smoke? Do we have any recommendations for derating the operational temperature / power consumption of power supplies as the operational altitude increases? Any information or ideas you have would be appreciated. Regards, Carmen Filimon Leitch Canada --- 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: SMPS Derating reqs for Altitude range of 5000-10000ft
Carmen If your power supply is approved to IEC60950, then normally it will be approved upto 2000m. Above this altitude the required creepage and clearance distances start to increase. It is an electrical insulation issue, not a thermal issue. Carmen.Filimon wrote: Hi All I'm trying to find out what the specified operational altitude range(s) is (are) for power supplies (particularly switching mode ones). Do any of you know what that spec may be, and particularly what is the rule for derating at altitude for thermal issues. Many manufacturers don't specify a maximum altitude but instead design in enough thermal overhead to accommodate any reasonable terrestrial location. According to GR-63-CORE the operating range without derating is 1800m above sea level. If derating is required above 1800m then the manufacturer must specify any additional requirements. Is it a safety derating factor so that customers at 5000-1ft don't smell smoke? Do we have any recommendations for derating the operational temperature / power consumption of power supplies as the operational altitude increases? Any information or ideas you have would be appreciated. Regards, Carmen Filimon Leitch Canada --- 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. -- Andrew Carson - Senior Compliance Engineer, Xyratex, UK Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 --- 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
There is a difference between extending a warranty and being liable for failure. If your seat belts fail some time after the warranty is up, the manufacturer won't pay for fixing them on your car. But the manufacturer may well be held liable for the failure. Cortland Andrews, Kurt wrote: From what I have found out it is not a requirement for safety related items to be warranted for the life of the car. I have recently been shopping for a --- 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
AIrbag testing? Well, since it costs about $US 1500 to replace them (here), I suppose there WOULD be a price hike! One of the tests run on a modern, computerized auto when the ignition is turned on is for airbag activation circuitry. Cortland James, Chris wrote: I don't believe airbags are tested but guess it will come, along with the inevitable hike in price. --- 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.
Warranties vs. Performance
Note that vehicle warranties merely assert that the named parts or systems will be replaced by the dealer (or authorized repair shop) at no cost if they go bad. They do NOT guarantee that they will not fail within the stated time/mileage. For example, suppose the brakes fail, or air bag deploys for no reason, resulting in an accident. The warranty merely means that the defective parts will be replaced. The free replacement of safety parts would be little consolation if someone died in the accident. George Alspaugh --- 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 cherryclo...@aol.com wrote (in 131.6a66623.296 70...@aol.com) about 'EMC-related safety issues', on Fri, 4 Jan 2002: As I recall, the EU's Product Liability Directive (85/374/EEC amended by 99/34/EC) requires manufacturers to produce products that are: as safe as people generally have the right to expect. I believe it does. Note that it does not require things to be 100% safe - that is impossible. Indeed. The real problem is that whether a product really is as safe as people generally have the right to expect is usually tested in a court of law where there are lots of photographs of a dead or maimed person or a burnt-down building, or whatever. It is difficult to argue that your product is safe enough when there are relatives sobbing all over the courtroom. Indeed. The trick, I believe, is not to be in that position in the first place. Design your products using the latest safety knowledge and test them well to discover if they have any weaknesses you did not address. How do you decide what tests to do **for weaknesses you don't suspect**? Isn't that fundamentally impossible? And yes, you must consider foreseeable misuse and stupid users too. (The trouble with trying to make something foolproof is that fools are so ingenious!) Exactly! Is replacing the mains fuse in a product with a bit of fencing wire 'foreseeable misuse'? I have put this question to an IEC safety committee; it's not just a debating point! Then hopefully you won't ever find yourself trying to defend your design decisions in a court of law. Hopefully! Will your CEO accept that 'hopefully' your design won't put him in jail for corporate manslaughter? But can you ever give a better assurance than 'hopefully', at the necessary 1 in a billion probability level? I think not. Also, your company's exposure to significant financial and commercial risks will be reduced - this is the key to justifying the expense of good safety design to your employers. But it seems that the expense of 'good safety design', as determined by some safety experts, is going through the roof. -- 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 cherryclo...@aol.com wrote (in 17d.1b28bc2.296 70...@aol.com) about 'EMC-related safety issues', on Fri, 4 Jan 2002: Does anyone else think that ordinary semiconductors doesn't respond to RF? Your experience has been shared by thousands. The demodulation normally occurs at the first semiconductor junction that the r.f signal 'sees', although at 10 V/m there may be propagation effects. The faulty reasoning that makes this effect surprising is 'silicon diodes and transistors need 0.6 V forward bias in order to conduct'. It isn't TRUE! If you add 'more than a few microamps' it's less untrue. But conduction occurs right down to minute signal voltages, resulting, certainly, in even more minute currents, but current enough to cause trouble. 'Underbiased' junctions act as excellent square-law detectors; for every 1 dB increase in input signal level you get 2 dB increase in level of recovered modulation. You may well find that JFET-input op-amps are far less sensitive to r.f. A test that I carried out a while back, on a very simple board with no EMC counter-measures at all, indicated a 26 dB difference between an LM324 and a TL072, the difference being substantially independent of frequency from 150 kHz to 1 GHz. -- 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
Warranted parts for a car is a whole other discussion. Warranties are simply for as long as the mfr/dealer want to do the contract. I'm not sure if there's a law concerning minimum time of warranty or if it's simply driven by the free market. Supplying a parts inventory by the car mfr is I think is required for a maximum of up to 10 years. The contract for making that part is then picked up by some other shop who thinks they can turn a profit. I can't imagine Moter Vehicles passing a car for inspection with a big gaping hole in the dash or steering column where the air bag used to be. But I'll be the first to admit that I don't know any of the laws requiring parts such as selt belts and air bags being replaced years down the road. I did have an experience back in the early 80's in trying to replace a faulty seatbelt with a used one and I was prohibited from doing that. I had to buy a new one. That was back in CT so that may have been a state thing. I can only think of at least one or two modes of transportation that are covered by federal law for replacement parts being available for the entire life of the thing for as long as that may be - jet airliners and trains. Elevators and escalators also come to mind as well. Anyone here work at Otis? - 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.
Re: EMC-related safety issues
I read in !emc-pstc that cherryclo...@aol.com wrote (in 167.698dddc.296 70...@aol.com) about 'EMC-related safety issues', on Fri, 4 Jan 2002: As my paper at the IEEE's EMC Symposium in Montreal and my recent article in ITEM UPDATE 2001 show - at present EMC standards don't address safety issues, and most safety standards don't address EMC-related functional safety issues. As far as CENELEC is concerned, it was a conscious decision not to incorporate 'EMC and Safety' issues into EMC standards, but to treat it as a separate subject. Some people may find a clarification helpful. We have EMC matters, concerned with compatibility between items of equipment, ensuring that they continue to work (Criterion A in the Generic Standards) or fail gracefully (Criteria B and C). These criteria do not address safety issues, as indicated in paragraph 1 above. However, the Generic Standards do have a limited 'blanket' requirement, that equipment must not become unsafe *during testing*. We also have safety matters per se, which don't involve EMC. We ALSO have the separate subject, called 'EMC and Safety' or reasonable variants thereof. This addresses the matter of equipment becoming unsafe *in service* due to excessive emission levels in the environment, or lack of sufficient immunity to acceptable emission levels. So far, this seems perfectly reasonable. BUT it stops seeming reasonable when the question 'What could go wrong?' is asked and statistical data is used to attempt to answer it. To take a very simple example (maybe over-simplified), we might say that the probability of an unsafe occurrence should be less than 10^-9. That immediately means that the designer of the equipment has to look at ALL risk scenarios down to the billion-to-one against level of probability. To say that that is difficult is surely a great understatement. But some experts in the field seem to ignore that great difficulty, and simply (or maybe not so simply) state that if the designer fails to take into account ANY scenario that subsequently results in an unsafe condition, the designer has failed in his professional responsibility, and may be held criminally responsible for negligence. Well, let us be very circumspect designers and look at what immunity levels we might need to get down to that 10^-9 probability. For radiated emissions, the necessary test levels seem to be of the order of 100 V/m. Test levels for other disturbances seem to be equally distantly related to the levels normally experienced and to the test levels in pure EMC standards. We might conclude that assessment of EMC immunity per se is completely unnecessary, because testing for 'EMC and Safety' requires test levels of the order of 30 dB higher! One could go, with the sort of reasoning advocated by some experts, further into the realms of fantasy. Suppose, for a particular piece of equipment, the designer, with great diligence, identifies a million threat scenarios, each of which has a probability of 10^-9. The cumulative probability of ANY ONE of them occurring is only 10^-3. Bit risky, that! If the above reasoning seems flawed, consider a specific case, a lottery with 2000 tickets, numbered to 1999. One person can buy up to 5 tickets, and all tickets are sold. Consider the probability of a 'remarkable occurrence'. This might be the drawing of the number '' or '' or '1234' or even '1010', depending on what you think is 'remarkable'. OK, we already have a cumulative probability down from 1 in 2000 to 1 in 667 or 1 in 500. Now add in the probability that a participant in the lottery is chosen at random to draw the winning number, and draws (one of) his or her own numbers .. You shouldn't be able to get very long odds on a 'remarkable occurrence'! -- 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
Chris, Annual inspections of motor vehicles are done on a state by state basis, rather than as a national requirement in the U.S. Automobiles are registered at the state level, so the federal government doesn't get involved. Some states have annual inspections, others don't. Likewise, smog inspections are at a state or lower level. California cars get smogged. Here in Washington it depends on what county you live in. If air quality in your county is good enough, you don't have to have your car smogged. If not, you get to pay more for the privilege of having a car. I live in a county where I don't have to deal with the fight. BTW, a trick I learned when I lived in California is that you stand a much better chance of passing the smog test if the engine is well warmed up when you arrive at the inspection station. Take it for what it's worth. Be thankful that we don't have to have annual inspections on our cars to the extent that one does on an airplane... $$$ Ghery Pettit Intel -Original Message- From: James, Chris [mailto:c...@dolby.co.uk] Sent: Friday, January 04, 2002 1:02 AM To: 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group Subject: RE: EMC-related safety issues Sorry disagree about turn and brake lights not being in the same class. Their very failure is often the reason for very serious accidents. I have long wished that all car manufacturers had to by law fit bulb failure warning devices to cars (but what happens when that fails). In the UK it is an offence to drive a vehicle with defective lights, (although many do). It is the driver's (not owner's) obligation to be satisfied the vehicle they are driving is fit to be on the road irespective of whether it passed it's MOT the previous day. The UK mandatory annual vehicle inspection (MOT) for vehicles over 3 years old, covers seat belts, brake efficiency on a rolling road, mirrors, windshield cracks (a 20mm, 3/4inch crack in the wrong place will fail a vehicle), tyres, wheel bearings, gaiters, steering components, structural body condition, lights, smog emissions, etcI don't believe airbags are tested but guess it will come, along with the inevitable hike in price. I'm surprised the US does not have a similar Federal requirement - with all the vehicles this is a cash cow waiting to be milked. Chris -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: 04 January 2002 02:40 To: Doug McKean; EMC-PSTC Discussion Group Subject: Re: EMC-related safety issues A signal light is easily replaceable in terms of time and money. Most people don't use them (well, in good old Huntsville, AL, anyway, where a favorite bumper sticker reads, Turn signals, not just for smart people anymore). Failure of a light is not in the same class as an airbag deploying at the wrong time or not deploying, or ditto for brakes. -- From: Doug McKean dmck...@auspex.com To: EMC-PSTC Discussion Group emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 7:00 PM Point taken Ken, but consider signal lights. They're essentially safety devices and they're supposed to be maintained on cars which have been transferred amongst several owners and are decades old. Same idea with windshields, I guess also. - 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. --- 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
SMPS Derating reqs for Altitude range of 5000-10000ft
Hi All I'm trying to find out what the specified operational altitude range(s) is (are) for power supplies (particularly switching mode ones). Do any of you know what that spec may be, and particularly what is the rule for derating at altitude for thermal issues. Many manufacturers don't specify a maximum altitude but instead design in enough thermal overhead to accommodate any reasonable terrestrial location. According to GR-63-CORE the operating range without derating is 1800m above sea level. If derating is required above 1800m then the manufacturer must specify any additional requirements. Is it a safety derating factor so that customers at 5000-1ft don't smell smoke? Do we have any recommendations for derating the operational temperature / power consumption of power supplies as the operational altitude increases? Any information or ideas you have would be appreciated. Regards, Carmen Filimon Leitch Canada --- 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
No, it's simply that it isn't considered reasonable to have a radio and a CFL in close proximity. If you want a lamp and a radio close together, use an incandescent lamp. That's the bottom line, isn't it? Somebody has decided for me (in terms of what is reasonable) that if I use a CFL, then I must separate it from a radio by 3 m or more. So, I am acting unreasonably by using a CFL and a radio on my bedside table. :-( Rich --- 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.
December, 2001 EMC/Telco/Product Safety Update Now Available
The Curtis-Straus Update is for December, 2001 is now available at: http://www.conformity-update.com The headlines are: Commission Re-evaluates HAC Requirements For Digital Wireless. Proposed Part 15 Changes Published. FCC Upgrades Web Site To Include New Search Capabilities. Failing To Disclose Costs Honeywell $800,000. More Notebook Computer Batteries Recalled. EU Publishes Additional Standards For Medical Devices, Machinery. CISPR Realigns Standards Development Committees. Standards Update. Meetings and Seminars. --- 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.
Selection of Directives
Hi all, Me again... My primary focus over the last few years has been limited to ITE and 2.4GHz SS radio products. My contact lists and web page book marks are filled with the necessary links to information regarding these types of products and I am very comfortable with obtaining compliance with the required Directives that apply.I am now exposed to many types of products destined for the EU and want to make sure to apply the proper directives and standards. Where is the magical matrix that one can pick his directive and test suite from for a given type of product? Kind Regards, Sam Wismer Engineering Manager ACS, Inc. Phone: (770) 831-8048 Fax: (770) 831-8598 Web: www.acstestlab.com
RE: Something a little different - Car Radio question
1. Does the radio work reasonable well on FM? If so, then the antenna is probably connected correctly. 2. Car radios used to have a variable capacitor that needs to be adjusted to match the antenna being used. (Haven't been that business for several years, so I don't know what they do now.) Sometimes this is accessible through the tape player door on the front, behind some removable piece on the front, or from the back. If not adjusted, AM reception can be VERY poor. Some novice installer may not know this. This should be in the installations/owners manual. 3. Some car radios have an internal antenna switch (electronic) that switches the antenna lead from the FM RF input stage, to the AM mixer (often no RF stage). Could be faulty. 4. If the problem is noise blanking all AM stations, could be faulty plug wiring in the vehicle, but this is very unlikely since the previous radio worked well. 5. Just what are the symptoms -- no noise, white noise and no signal, loud popping noise, . Good luck, Mike Hopkins Thermo KeyTek -Original Message- From: Cortland Richmond [mailto:cortland.richm...@alcatel.com] Sent: Thursday, January 03, 2002 6:32 PM To: Charles Grasso Cc: emc-p...@majordomo.ieee.org Subject: Re: Something a little different - Car Radio question Some cars do this? Nonsense! As you of course know. 1. It may be that your windshield antenna will not work with the particular model radio you got, which would only mean drilling a small hole and installing a whip. You should be able to find this out by calling the manufacturer and asking. 2. Less charitably, the folks who put your radio in may have broken your windshield antenna (necessitating a replacement windshield, which they will NOT want to pay for) and are either unable to figure it out, unwilling to fix it, or are trying to force you into having a different, and more expensive, radio installed. That last is called bait and switch and borders on the criminal in most states. Some obvious reactions come to mind. Calling the national or regional Best Buys office. Calling your state's consumer protection office (they may have handled pervious complaints from this store.) Suing them repair the damage to your car. Others are probably forthcoming, here! Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Charles Grasso wrote: Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the world's largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at:
RE: EMC-related safety issues
From what I have found out it is not a requirement for safety related items to be warranted for the life of the car. I have recently been shopping for a new car and one of the ones I looked at is the Toyota Celica. It states the following in the brochure: The seat belts and air bags are covered under the powertrain warranty which is for 5 years or 60,000 miles. The emission control components are also not covered for the life of the car. The brochure states that components covered under the Federal emission defect warranty are covered for 3 years or 36,000 miles and specified major emission control components are covered for 8 years or 80,000 miles. My current car, a 1990 Acura Integra, has the following coverage. The anti-lock brakes are covered under the normal 3 year/36,000 mile coverage. According to the owners manual the seat belts are covered for the life of the car because Acura considers them vital to safety. The car does not have airbags, it has those stupid mouse (automatic) seatbelts. So it appears that the only reason that the seat belts are covered longer than the standard warranty is because Acura chose to do so, not because they have to (and I applaud them for that). I do not recall what the warranty is on the emission control components. I would suspect it is the same as the Toyota if the federal rules were the same in 1990 as they are now. Kurt Andrews Compliance Engineer Tracewell Systems, Inc. 567 Enterprise Drive Westerville, Ohio 43081 voice: 614.846.6175 toll free: 800.848.4525 fax: 614.846.7791 http://www.tracewellsystems.com/ -Original Message- From: Doug McKean [mailto:dmck...@auspex.com] Sent: Thursday, January 03, 2002 5:43 PM To: EMC-PSTC Discussion Group Subject:Re: EMC-related safety issues Ken Javor wrote: Curiosity. How long must airbags work? As long as you have the car, supposedly. Same with seat belts. They're all safety features. Interestingly, if you have a cracked or broken windshield, a cop *can* write you up for the car being unsafe. I've never heard of it, but a classmate of mine who became a statie told me when he saw a huge crack in my windshield. I'm also under the impression that manufacturers are responsible for maintaining a repair/replacement parts inventory to dealers for only 10 years. Not sure about that one. - 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. --- 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: CEN Standards free on-line
For those of you having difficulty with the link - the link overflowed onto the next line. You will have to paste it back together to obtain the full and correct link. And John is correct. Someone forget to tell the CEN website that the documents are now free. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, January 04, 2002 1:39 AM To: emc-p...@majordomo.ieee.org Subject: Re: CEN Standards free on-line I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FDD@flbocexu05) about 'CEN Standards free on- line', on Thu, 3 Jan 2002: According to this press release, CEN standards should now be on line for free. http://europa.eu.int/rapid/start/cgi/guesten.ksh?p_action.gettxt=gtdoc=IP/ 0 1/1837|0|RAPIDlg=EN It does indeed say that, BUT the CEN web page itself still refers one to national standards bodies for purchasing the standards! No mention at all of any free downloads! -- 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
As I understand the way the civil law section of the EU's Product Liability Directive operates (I am not a lawyer) it does in fact place the burden of proof on the manufacturer, who is effectively considered 'guilty until proved innocent'. I also understand that any number of manufacturers can be sued in the civil courts under one safety incident, and the liabilities of each awarded 'on the balance of probabilities' that their product caused the damage, injury or death being complained about. Also...nobody has to prove negligence on the part of the manufacturer, this is sometimes called 'no-fault liability' - you can be held to be liable under the law even though nobody has proved that your product was actually the cause of the safety incident. Another interesting fact about EU Product Liability is that in the civil courts in most EU member states there is no financial upper limit to the damages that can be awarded against a manufacturer. We may not like it, but that's how the world appears to be at the moment. Regards, Keith Armstrong In a message dated 03/01/02 19:52:20 GMT Standard Time, j...@jmwa.demon.co.uk writes: Subj:Re: EMC-related safety issues Date:03/01/02 19:52:20 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 Gary McInturff Gary.McInturff@worldwidepackets .com wrote (in 917063bab0ddb043af5faa73c7a835d40ac...@windlord.wwp.com ) about 'EMC-related safety issues', on Thu, 3 Jan 2002: While I take your point - I'll challenge with the equally valid argument that says show me the data that they do cause SIDS! Out of order! That's the whole point! Manufacturers are being required to prepare to prove a negative, which is inherently impossible in most cases. No-one is required to prove a positive, which is easy if it is true. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Re: EMC-related safety issues
Hey, Ken, let's try to be realistic here!
Sure - we should try to get laws we don't like changed, but that isn't going
to happen overnight and in the meantime we have to operate within the law as
it stands.
Or are you suggesting immediate insurrection by product manufacturers?
(Outlaw manufacturers roaming the wild wild west - an interesting concept!)
The IEE's guide on EMC and Functional Safety is concerned with such legal
aspects, but is also concerned with saving lives in a world where electronic
control of safety-related functions is proliferating madly.
As my paper at the IEEE's EMC Symposium in Montreal and my recent article in
ITEM UPDATE 2001 show - at present EMC standards don't address safety issues,
and most safety standards don't address EMC-related functional safety issues.
Regards, Keith Armstrong
In a message dated 03/01/02 17:24:42 GMT Standard Time,
ken.ja...@emccompliance.com writes:
Subj:Re: EMC-related safety issues
Date:03/01/02 17:24:42 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:c...@dolby.co.uk (James, Chris), acar...@uk.xyratex.com
('acar...@uk.xyratex.com'), emc-p...@majordomo.ieee.org
There is an inherent contradiction in this anti-profit, anti-technology
point-of-view that I cannot and will not defend. All I am saying is that
people who feel this is wrong should stand up and say so, not write guides
for how to go along with it.
Re: CEN Standards free on-line
FREE STANDARDS? It seems from the wording that only Standards relating to e-business are to be free, which one assumes could include a myriad of Standards but I wonder who will decide which ones and when. Perhaps any members of Standards Committees could throw more light on this topic. I will certainly try and find out via press sources. Alan E Hutley EMC Compliance journal www.compliance-club.com - Original Message - From: John Woodgate j...@jmwa.demon.co.uk To: emc-p...@majordomo.ieee.org Sent: Friday, January 04, 2002 6:39 AM Subject: Re: CEN Standards free on-line I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FDD@flbocexu05) about 'CEN Standards free on- line', on Thu, 3 Jan 2002: According to this press release, CEN standards should now be on line for free. http://europa.eu.int/rapid/start/cgi/guesten.ksh?p_action.gettxt=gtdoc=IP/ 0 1/1837|0|RAPIDlg=EN It does indeed say that, BUT the CEN web page itself still refers one to national standards bodies for purchasing the standards! No mention at all of any free downloads! -- 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
Does anyone else think that ordinary semiconductors doesn't respond to RF?
I have tested a product which was little more than an LM324 quad op-amp for
RF immunity using IEC 61000-4-3. This op-amp has a slew rate of
1V/micro-second on a good day with the wind in its favour. It was housed in
an unshielded plastic enclosure.
Demodulated noise that exceeded the (not very tough) product specification
were seen all the way up to 500MHz at a number of spot frequencies that
appeared to be due to the natural resonances of the input and output cables.
Above 500MHz this resonant behaviour vanished to be replaced by a steadily
rising level of demodulated 1kHz tone as the frequency increased. I stopped
testing at 1GHz, where the output error from the product was about 10% and
still rising with increased frequency.
OK, the field strength for the test was 10V/m (unmodulated) but the real
surprise was how well this very cheap and very slow opamp demodulated the RF,
and that it demodulated better at 1GHz than at 500MHz.
I have done many many immunity tests using IEC 61000-4-3 on audio equipment
and found much the same effects with every product I've ever tested.
With most larger products there is usually a roll-off in the demodulation
above 500MHz - not because the semiconductors in the ICs can't respond (they
can) but apparently because larger products have higher losses above 500MHz
or so between the cable ports and the semiconductors, plus a denser structure
that might provide more self-screening.
The transistors and diodes in all modern ICs (analog or digital) are so tiny
that they make excellent detectors at UHF and beyond. As they get smaller
(and they are) their frequency response increases (and their vulnerability to
upset and damage decreases).
Regards, Keith Armstrong
In a message dated 03/01/02 23:27:19 GMT Standard Time,
ken.ja...@emccompliance.com writes:
Subj:Re: EMC-related safety issues
Date:03/01/02 23:27:19 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:m...@california.com (Robert Macy), ghery.pet...@intel.com (Pettit,
Ghery), james.col...@usa.alcatel.com ('James Collum'),
emc-p...@majordomo.ieee.org
Emissions from a laptop are naturally (without suppression) on the order of
10 uV/m to 100s of uV/m. 1000 uV/m would represent at least a 20 dB outage
at frequencies that could possibly interfere with sensor electronics. The
coupling is lossy: 1 mV/m will generate far less than 1 mV signal in the
electronics, and this at rf. Does anyone really see this as a remotely
possible mechanism? I don't.
--
From: Robert Macy m...@california.com
To: Pettit, Ghery ghery.pet...@intel.com, 'James Collum'
james.col...@usa.alcatel.com, emc-p...@majordomo.ieee.org
Subject: Re: EMC-related safety issues
Date: Thu, Jan 3, 2002, 3:25 PM
Perhaps, it merely interfered with the sensor electronics, not the true
magnetic field that was being sensed.
- Robert -
Robert A. Macy, PEm...@california.com
408 286 3985 fx 408 297 9121
AJM International Electronics Consultants
619 North First St, San Jose, CA 95112
-Original Message-
From: Pettit, Ghery ghery.pet...@intel.com
To: 'James Collum' james.col...@usa.alcatel.com;
emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org
Date: Thursday, January 03, 2002 11:46 AM
Subject: RE: EMC-related safety issues
I still have a hard time believing it was a compass that was affected
by
a laptop computer. ADF indication, could be. VOR, maybe. Magnetic
compass? I wouldn't want a magnetic source that strong in my lap! My
belt
buckle would be stuck to it. There is quite a distance between a magnetic
compass in the cockpit of an airliner and anything a passenger is
carrying.
Not so in a Cessna 172, but in a DC-10?
Ghery Pettit
-Original Message-
From: James Collum [mailto:james.col...@usa.alcatel.com]
Sent: Thursday, January 03, 2002 10:47 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: EMC-related safety issues
*
A routine flight over Dallas-Fort Worth was disrupted when one of
the compasses suddenly shifted 10 degrees to the right. The pilot asked
if
any passenger was operating an electronic device, and finding that a
laptop
computer had just been turned on requested that it be turned off,
whereupon
the compass returned to normal. Following RTCA guidelines the pilot
requested that the laptop be turned on again 10 minutes later, when the
compass error returned.
Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12
*
I am fascinated by this amazing story
Re: EMC-related safety issues
The IEE's guide on EMC and Functional Safety is concerned with helping engineers and managers avoid legal problems - but I don't call this appeasement, just good practice. But the guide is also concerned with saving lives in a world where electronic control of safety-related functions is proliferating madly. As my paper at the IEEE's EMC Symposium in Montreal and my recent article in ITEM UPDATE 2001 show - at present EMC standards don't address safety issues, and most safety standards don't address EMC-related functional safety issues. Regards, Keith Armstrong In a message dated 03/01/02 20:04:46 GMT Standard Time, ken.ja...@emccompliance.com writes: Subj:Re: EMC-related safety issues Date:03/01/02 20:04:46 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:cortland.richm...@alcatel.com (Cortland Richmond), acar...@uk.xyratex.com (Andrew Carson) CC:emc-p...@majordomo.ieee.org Curiosity. How long must airbags work? A car can be driven for two decades or more, by an uncontrolled number of owners, and with no mandatory inspection or service. How long is a manufacturer liable for the proper operation of those airbags? Same question for anti-lock brakes. If the warning light comes on and is ignored, who is at fault? If the warning light is disabled by an owner, and the next owner suffers injury due to improper operation of either of these systems, who is at fault? Don't give me the logical answer. I can figure that out. Knowing that the culpable seller is not a tempting target but the manufacturer is, in the present climate some bright lawyer will come up with a rationale for suing the manufacturer. It is the climate that must be changed and the IEE guide that started this thread, in my opinion, appeases this trend rather than opposes it. -- From: Cortland Richmond cortland.richm...@alcatel.com To: Andrew Carson acar...@uk.xyratex.com Cc: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 12:22 PM As engineers, we should consider the safety implications of what we design, test or otherwise work on. EMI is part of that. What is considered a safety risk depends a great deal on corporate policy, the legal, political and popular climate in one's state of residence, and the kind of equipment under consideration. As it happens, the issue of pacemaker vulnerability is addressed in more regulations than USC 47. That is why, in the United States, we have not only a limit on microwave oven leakage, but also pacemaker warning signs on microwave ovens used by the public. The robotic arm is a great example. Others are automotive airbags, or electronically controlled brakes. These sort of things are the reason why industry associations develop limits of their own. Those limits accommodate both a performance requirement and practical aspects; they can't make the product too expensive to build or no one will be able to sell them at a profit. They can't be unreliable in the field or people won't buy them at all. And they can't cause too many problems, or the company will be sued. One factor weighs against another. We are at the balance point. Regards, Cortland Richmond (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Andrew Carson wrote: I get the idea that we a missing the whole point of this discussion. Should we as Professional Safety Engineers and Product designers consider the safety implications of EMC emissions ? The answer is a definite Yes. We have a clear duty of care and responsibility to consider all implications of our products being used in there intended application. Even if the consideration on EMC emissions and safety is Do not be silly. We still have to at least consider it. ...
Asian EMC regulations
Can anyone help me? I need to find the relevant EMC standards for IT equipment when it is supposed to be deployed in the following Asian countries: Korea (CISPR 24/22 ??), Hong Kong, Singapore, Malaysia, China (CNS 13438 ??), Taiwan and Japan (VCCI (V-3/97-04) ??). If you have a link to a description of the needed standards please contact me. Although this might not be the correct forum for this, but I am also looking for a list of the safety and telecommunications standards to comply with in the above countries - anybody who has a good link to a description of the Asian regulatory requirements? Most all countries now accept safety compliance to IEC 60950 or equivalent. Here is the little I know of these country ITE safety req'mnts. Koreacert. required by KSA (e.g. KTL) Hong Kongno cert. requirements Singaporecert. required by PSB for consumer ITE Malaysia no cert. requirements Chinacert. required via CCIB (soon to be CCC) Taiwan no cert. requirements, accepts UL marking Japanno cert. requirements for ITE, except PSE for AC/DC adapters George --- 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: Lasting of the CE marking
You can find the Commissions explanation of the use of harmonized standards in their Guide to the implementation of directives based on the New Approach and the Global Approach. It is available on line for a free download. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Kim Boll Jensen [mailto:kimb...@post7.tele.dk] Sent: Thursday, January 03, 2002 3:55 PM To: EMC-PSTC Subject: Lasting of the CE marking Hi all I was just seeking through EMC LVD RTTE and MD directives for evidence of my interpretation but I couldn't find it, so can some of you help me. As I recall there are the following rules: For EMC directive you will always have to produce according to the latest harmonized standards (after dow date) For all other directives you just use the harmonized standards which was acceptable at the time of entry to the market (then you can produce the same product for decades without retesting to new harmonized standards) Please help me finding the clauses in the directives which supports this statement. But what about RTTE when new standards are harmonized where no standards was before ? Best regards, Kim Boll Jensen Bolls Raadgivning --- 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.
SV: Lasting of the CE marking
Agree John, I would also expect that the RTTE follows the same procedure as EMC and LVD. Have done some search, but I have not found any references. Amund -Opprinnelig melding- Fra: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av John Woodgate Sendt: 4. januar 2002 03:11 Til: emc-p...@majordomo.ieee.org Emne: Re: Lasting of the CE marking I read in !emc-pstc that Kim Boll Jensen kimb...@post7.tele.dk wrote (in 3c34c51e.6e41b...@post7.tele.dk) about 'Lasting of the CE marking', on Thu, 3 Jan 2002: Hi all I was just seeking through EMC LVD RTTE and MD directives for evidence of my interpretation but I couldn't find it, so can some of you help me. As I recall there are the following rules: For EMC directive you will always have to produce according to the latest harmonized standards (after dow date) For all other directives you just use the harmonized standards which was acceptable at the time of entry to the market (then you can produce the same product for decades without retesting to new harmonized standards) No, the LVD requires exactly the same application of standards as the EMC Directive. I expect the RTTE Directive is the same, but I haven't studied it. -- 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.
Asian EMC regulations
Hello All, Can anyone help me? I need to find the relevant EMC standards for IT equipment when it is supposed to be deployed in the following Asian countries: Korea (CISPR 24/22 ??), Hong Kong, Singapore, Malaysia, China (CNS 13438 ??), Taiwan and Japan (VCCI (V-3/97-04) ??). If you have a link to a description of the needed standards please contact me. Although this might not be the correct forum for this, but I am also looking for a list of the safety and telecommunications standards to comply with in the above countries - anybody who has a good link to a description of the Asian regulatory requirements? Best regards, Rasmus Rasmus Carlson Technical Marketing Engineer www.firstmilesystems.com Direct: +45 45 17 41 75 FirstMile Systems A/S Fax:+45 45 17 41 71 Slotsmarken 18 Mobile: +45 24 27 54 24 2970 Hørsholm, Denmark Mailto:r...@firstmilesystems.com
RE: EMC-related safety issues
Sorry disagree about turn and brake lights not being in the same class. Their very failure is often the reason for very serious accidents. I have long wished that all car manufacturers had to by law fit bulb failure warning devices to cars (but what happens when that fails). In the UK it is an offence to drive a vehicle with defective lights, (although many do). It is the driver's (not owner's) obligation to be satisfied the vehicle they are driving is fit to be on the road irespective of whether it passed it's MOT the previous day. The UK mandatory annual vehicle inspection (MOT) for vehicles over 3 years old, covers seat belts, brake efficiency on a rolling road, mirrors, windshield cracks (a 20mm, 3/4inch crack in the wrong place will fail a vehicle), tyres, wheel bearings, gaiters, steering components, structural body condition, lights, smog emissions, etcI don't believe airbags are tested but guess it will come, along with the inevitable hike in price. I'm surprised the US does not have a similar Federal requirement - with all the vehicles this is a cash cow waiting to be milked. Chris -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: 04 January 2002 02:40 To: Doug McKean; EMC-PSTC Discussion Group Subject: Re: EMC-related safety issues A signal light is easily replaceable in terms of time and money. Most people don't use them (well, in good old Huntsville, AL, anyway, where a favorite bumper sticker reads, Turn signals, not just for smart people anymore). Failure of a light is not in the same class as an airbag deploying at the wrong time or not deploying, or ditto for brakes. -- From: Doug McKean dmck...@auspex.com To: EMC-PSTC Discussion Group emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 7:00 PM Point taken Ken, but consider signal lights. They're essentially safety devices and they're supposed to be maintained on cars which have been transferred amongst several owners and are decades old. Same idea with windshields, I guess also. - 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. --- 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: Something a little different - Car Radio question
Might seem a silly question but does the new unit have AM? Some of the new car CD players only have FM. If it does have AM then what do you hear when trying to tune it? Perhaps the AM stage is faulty and the fitting shop just tried to fob you off Regards, Chris __ Chris James Engineering Services Manager Dolby Laboratories, Inc. (UK) www.dolby.com -Original Message- From: Charles Grasso [mailto:chasgra...@hotmail.com] Sent: 03 January 2002 21:08 To: emc-p...@majordomo.ieee.org Subject: Something a little different - Car Radio question Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the world's largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: CEN Standards free on-line
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FDD@flbocexu05) about 'CEN Standards free on- line', on Thu, 3 Jan 2002: According to this press release, CEN standards should now be on line for free. http://europa.eu.int/rapid/start/cgi/guesten.ksh?p_action.gettxt=gtdoc=IP/0 1/1837|0|RAPIDlg=EN It does indeed say that, BUT the CEN web page itself still refers one to national standards bodies for purchasing the standards! No mention at all of any free downloads! -- 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 - lighting noise
George is correct so far as normal fluorescent, and of course, incandescent, lighting. These are not regulated for emissions in the US. But the new energy-saving RF lighting devices (bulbs) are regulated under FCC Part 18. The limits appear to be quite generous. The regulations are found in 18.305 for radiated (above 30 MHz) and in 18.307 for conducted (including the AM/MW Broadcast band). I recall that the ARRL fought the relaxation of the emission limits because some lamps operate (if I tremember correctly) in the amateur 20 meter band or nearby (maybe 13.56 MHz ??). Jack Jacob Z. Schanker, P.E. 65 Crandon Way Rochester, NY 14618 Phone: 585 442 3909 Fax: 585 442 2182 j.schan...@ieee.org - Original Message - From: geor...@lexmark.com To: Rich Nute ri...@sdd.hp.com Cc: j...@jmwa.demon.co.uk; emc-p...@majordomo.ieee.org Sent: Thursday, January 03, 2002 4:32 PM Subject: Re: EMC-related safety issues | | | | I think the issue is that the lamp is not an EMC regulated | device. In fact, in Europe, ITE conducted emissions must | be regulated so as not to cause desk/room lights to flicker, | as in when a fuser lamp in a printer kicks on. | | Apparantly the proper functioning of lighting takes precedence | over the propoer functioning of radios and the like affected by | the lights? | | George | | | | | Rich Nute richn%sdd.hp@interlock.lexmark.com on 01/03/2002 04:08:51 PM | | Please respond to Rich Nute richn%sdd.hp@interlock.lexmark.com | | To: jmw%jmwa.demon.co...@interlock.lexmark.com | cc: emc-pstc%majordomo.ieee@interlock.lexmark.com (bcc: George | Alspaugh/Lex/Lexmark) | Subject: Re: EMC-related safety issues | | | | | | | | Hi John: | | |I've replaced the incandescent lamp on my bedside |table with a new energy-saving compact flourescent |lamp. With the lamp on, I cannot listen to even |the strongest AM radio station on my clock radio |(on the same bedside table) due to the lamp |interference. This must not be the usage |contemplated by EMC requirements. | |Limits in the household environment are based on a 3 m separation |between source and receiver. | | Wonderful! | | Either the lamp or the radio must be on the opposite | side of the room from my bedside table. When I am in | bed, one or the other is not controllable, and is | therefore useless to me. | | Whine mode on: I want both on my bedside table, and | I want both to do all of their functions. This IS | not the usage contemplated by 3 m separation EMC | requirements. | | :-) | | | Best wishes for the New Year, | Rich | | | | | --- | 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: Lasting of the CE marking
I read in !emc-pstc that Kim Boll Jensen kimb...@post7.tele.dk wrote (in 3c34c51e.6e41b...@post7.tele.dk) about 'Lasting of the CE marking', on Thu, 3 Jan 2002: Hi all I was just seeking through EMC LVD RTTE and MD directives for evidence of my interpretation but I couldn't find it, so can some of you help me. As I recall there are the following rules: For EMC directive you will always have to produce according to the latest harmonized standards (after dow date) For all other directives you just use the harmonized standards which was acceptable at the time of entry to the market (then you can produce the same product for decades without retesting to new harmonized standards) No, the LVD requires exactly the same application of standards as the EMC Directive. I expect the RTTE Directive is the same, but I haven't studied it. -- 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: -2dB margin
I read in !emc-pstc that George Stults george.stu...@watchguard.com wrote (in ea1b3684d553cbc96c23d33894bdfe4c3c350...@watchguard.com) about '-2dB margin', on Thu, 3 Jan 2002: After talking with some other folks, I've found that one can concoct a 2 dB margin from CISPR 22 [the section I mentioned below] as follows: Using the formula for statistically assessed compliance Xavg + K*StdDev Limit, assume that the StdDev is 1.0 and that you are initially testing one device as permitted. Then take the value of [K =2.04] for [n=3] and you have a 2.04 dB margin requirement for the initial device. The standard also requires that if you just test one device, that you do subsequent tests from time to time. So in effect, by going with a 2dB margin the first time, you're betting that the statistics will still be in your favor by the time you've tested 3 samples. Does anyone disagree that it could be done this way? It seems a reasonable explanation. An additional question would be, how is from time to time defined. Is it spelled out anywhere? Possibly not, but there is a principle that you can invoke. It was developed in the context of safety testing in service, AFAIK, but it works for other things. What you do is to choose an initial re-test period based on how many units you produce per unit time and how much unit-to-unit variability you expect. If you find that re-testing at this rate throws up failures, re-test more often. If it throws up no failures and not even marginal cases, re-test less often. -- 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 Rich Nute ri...@sdd.hp.com wrote (in 200201032108.naa11...@epgc264.sdd.hp.com) about 'EMC-related safety issues', on Thu, 3 Jan 2002: Whine mode on: I want both on my bedside table, and I want both to do all of their functions. This IS not the usage contemplated by 3 m separation EMC requirements. :-) Use an incandescent lamp. For a bedside table, quite a low power lamp is OK, especially if you use a low-voltage lamp. But keep a switch-mode 'electronic transformer' at least 3 m from the radio, of course! Or stick to an ordinary transformer. Old technology is NOT always BAD! Grandpa is your FRIEND. Since it isn't practicable to reduce the emissions of CFLs well below the limits of CISPR15/EN55015 without heroic measures, the 3 m separation has to be observed, or CFLs have to be banned or made much more costly. The latter possibilities are clearly not environmentally acceptable. -- 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 david_ster...@ademco.com wrote (in 2DF7C54A75B dd311b61700508b64231002c5a...@nyhqex1.ademcohq.com) about 'EMC-related safety issues', on Thu, 3 Jan 2002: My copy of BS EN 50140-4:1996 50140-4? ENV50140 was an early version of EN61000-4-3 and is withdrawn. -- 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 Kevin Harris harr...@dscltd.com wrote (in D886DC8708ACD3118A0500606DD5DA6328C655@DSC_MAIL) about 'EMC-related safety issues', on Thu, 3 Jan 2002: If the BSI site says that, then it is yet another proof of you can't always believe what you read. :) My Aug 2001 version of the BSI electronic catalog shows a publication date of 1996 for the BS EN ( but the document was actually released in late 1995) with an addendum A1 published in 1998. The hard copy sitting in front of me (from BSI) agrees with the electronic catalog :) There was a very generous transition period which ended in January of 2001. I'll check again. Maybe there was some sort of glitch. -- 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
Actually, if you consider that there are two issues here. First, the TV and Radio manufacturers are required to no longer have a wide-open front end as was prevalent quite a few years ago. This single action by the FCC improved the immunity (decreased the susceptability) to incidental RF. Secondly, by requiring the label to say must accept, eliminates a lot of complaints about LEGAL incidental as well as intentional radiators (you might also read that as easer to dismiss complaints). It was a start. John Shinn -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Doug McKean Sent: Thursday, January 03, 2002 2:36 PM To: EMC-PSTC Discussion Group Subject: Re: EMC-related safety issues Rich Nute wrote: EMC? Ha! You raise a good point since the FCC legally can but hasn't implemented an American version of immunity standards. The words must accept on the FCC labels of your effected devices are evident of it. Maybe some day we will have do immunity testing. - 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. --- 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: -2dB margin
After talking with some other folks, I've found that one can concoct a 2 dB margin from CISPR 22 [the section I mentioned below] as follows: Using the formula for statistically assessed compliance Xavg + K*StdDev Limit, assume that the StdDev is 1.0 and that you are initially testing one device as permitted. Then take the value of [K =2.04] for [n=3] and you have a 2.04 dB margin requirement for the initial device. The standard also requires that if you just test one device, that you do subsequent tests from time to time. So in effect, by going with a 2dB margin the first time, you're betting that the statistics will still be in your favor by the time you've tested 3 samples. Does anyone disagree that it could be done this way? An additional question would be, how is from time to time defined. Is it spelled out anywhere? George S. -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Wednesday, January 02, 2002 8:39 AM To: George Stults; 'emc-p...@majordomo.ieee.org' Subject: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: EMC-related safety issues
Point taken Ken, but consider signal lights. They're essentially safety devices and they're supposed to be maintained on cars which have been transferred amongst several owners and are decades old. Same idea with windshields, I guess also. - 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.
RE: Something a little different - Car Radio question
I think you are being blown off. If the antenna worked with AM before, and it is the SAME antenna, just a different receiver, then its the receiver, not the car... I would return that stereo immediately and have the guy who gave you that answer explain the phenomenon in detail to both you and his BestBuy manager... Happy New Year everyone, Robert Tims Engineering Project Leader Software Product Integration Ericsson Internet Applications, Inc. 145 Crossways Park Dr. W. Woodbury, NY 11797, USA Tel: 516-677-1138 Fax: 516-677- Pager: 516-891-8358 Email:robert.t...@ericsson.com -Original Message- From: Fred Townsend [mailto:f...@poasana.com] Sent: Thursday, January 03, 2002 6:35 PM To: Charles Grasso Cc: emc-p...@majordomo.ieee.org Subject: Re: Something a little different - Car Radio question This is not normal. I know of no normal situation where you would lose your AM reception. Sounds like the installer is tuned out. Complain to Best Buy management ASAP. Fred Townsend Charles Grasso wrote: Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the world's largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Re: Electric Shock and Water
If your colleage doesn't understand why you shouldn't mix water and electricity in general, just tell him that water has a tendency to be rather unpredictable and can go anywhere. Someone likened it to a three dimensional resistor and that's an excellent example. Add to it a very deformable 3D resistor. And since electricity likes to follow water, electricity will also end up going anywhere. Other than that, I agree it's a pretty naive question. I picture the guy in bare feet on the metal ladder in water with drill in hand asking, so what's the matter? - 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.
Re: Something a little different - Car Radio question
New one on me. The same antenna works for AM and FM, it just drives a higher load impedance on AM. -- From: Charles Grasso chasgra...@hotmail.com To: emc-p...@majordomo.ieee.org Subject: Something a little different - Car Radio question Date: Thu, Jan 3, 2002, 3:07 PM Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the worlds largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
