Re: EMC/Safety requirements for Uruguay
Check out the add for LARCG on page 16 of this month's issue of Conformity. LARCG stands for Latin America Regulatory Compliance Group. Their phone number is 800-297-5151. The web site is www.larcg.com. Their email is conform...@larcg.com. Good luck. Allen Tudor >From: "Charles Blackham" >Reply-To: "Charles Blackham" >To: "emc-pstc" >Subject: EMC/Safety requirements for Uruguay >Date: Tue, 30 Sep 2003 13:01:53 +0100 > >Could someone confirm the EMC/Safety requirements for IT equipment in >Uruguay? > >Are EN55022, EN55024, IEC60950 required / accepted ? > >regards >Charlie Blackham >Approvals Manager >Airspan Communications Ltd > _ Frustrated with dial-up? Get high-speed for as low as $29.95/month (depending on the local service providers in your area). https://broadband.msn.com This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: 94V-0 question
DuPont Nomex, GE Lexan, and GE Valox >From: drcuthb...@micron.com >Reply-To: drcuthb...@micron.com >To: >Subject: 94V-0 question >Date: Tue, 12 Aug 2003 11:55:25 -0600 > > >I need a sheet of plastic that goes between a PCB and a metal enclosure. >This is to make a creepage spec. What plastics are good for this? Will >polycarbonate be suitable and have a 94V-0 rating? Thanks. > >Dave Cuthbert >Micron Technology > > >--- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > >To cancel your subscription, send mail to: > majord...@ieee.org >with the single line: > unsubscribe emc-pstc > >For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: emc_p...@symbol.com > >For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > >Archive is being moved, we will announce when it is back on-line. >All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc _ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
EMC Contract job in St. Pete, Fla.
>From: "Anne Cameron" >To: >Subject: job description. Date: Mon, 16 Jun 2003 16:36:18 -0400 > >10 years experience in EMI-EMC-EMP testing of military electronics >equipment >and systems. with emphasis on the MIL-STD-461E and DO-1600 test >requirements >and design documents. The applicant must have experience operation EMI test >instrumentation, performing EMI and DO-1600 testing, writing EMI test >procedures and final test reports. NARTE Certification is desired. > >Thank you, > >Anne Cameron >HI-TEC Associates, Inc. >3651 Canton Road, Suite 201 >Marietta, GA 30066 >678-238-3400 >678-238-3401 fax >came...@hitecjobs.com >www.hitecjobs.com > > > _ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Voltage Breakdown
I remember seeing a figure for voltage breakdown through air recently, but can't remember what it is. Seems like it's 1mm per 1000 volts or something like that. Can anyone help? Specifically, I'm concerned about how much spacing is required between components and chassis to guard against electric field coupling during an ESD event. Thanks. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Voltage Breakdown
I remember seeing a figure for voltage breakdown through air recently, but can't remember what it is. Seems like it's 1mm per 1000 volts or something like that. Can anyone help? Specifically, I'm concerned about how much spacing is required between components and chassis to guard against electric field coupling during an ESD event. Thanks. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Book Review
Has anyone read Emi/Emc Computational Modeling Handbook by Bruce Archambeault, Colin Brench, Omar M. Ramahi? If so, what did you think of the book and did it help you in predicting EMI effects? Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
What's your experience with GTEM?
Greetings, I would appreciate any input with regard to GTEM results for pre-compliance emissions and immunity measurements. Specifically, is there a limit to the size of a product that can be tested? I have heard that small products such as pagers, etc. perform well in a GTEM. Is there a limit to product volume vs. volume of the GTEM? Also, how about cable radiation. Will the GTEM sufficiently detect cable radiation with comparable results with an OATS? Thanks in advance for your input. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: RE: Question on 15.31, Near-field
The distance of "one sixth lambda" comes from empirical data taken from a Hertzian dipole antenna. In his book Introduction to Electromagnetic Compatibility ISBN 0-471-54927-4, Clayton Paul writes: "The point where the 1/r3 (cubed) and 1/r2 (squared) terms become insignificant compared with the 1/r terms is referred to the boundary between the near field and far field. This occurs where r = lambda/(2*pi). The reader is cautioned that the boundary between the near and far fields for other antennas is not simply lambda/(2*pi), as is frequently assumed. A more realistic choice for the boundary between the near and far fields will be discussed later, but can be summarized as being the larger of 3*lambda or 2*D*D/lambda, where D is the largest dimension of the antenna." Simply stated, there exists some grey area between near and far field. It depends on how closely your product resembles a Hertzian dipole. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com >>> Meyerhoff Jerry-G10812 01/21 11:01 AM >>> Hello group. I substantially agree with the comments of Allen Tudor & Don Umbdenstock. My own view is : I believe the 40 dB / decade (of distance) is a approximation for extrapolating the measurement antenna location being reduced from 10 meter to 3 or possibly 1 meter in an effort to see the exceedingly weak emissions from well designed part 15 devices. However, below 30 MHz we're in the near-field of the source. 30 MHz is 10 meter wavelength and a 3 (or 1 meter) meter antenna site spacing "violates" the accepted one sixth lambda near field to farfield transition zone. Some would argue that 1 wavelength is a safer estimate of the transition zone. Then considering antennas like log periodics below 30 MHz which are huge, even that may not be large enough !! Or a 30 MHz (half-wave) dipole is 5 meters long . (as an aside.. How do you search 1 to 4 meters elevation in vertical polarization ?? (dig a hole for the lower dipole arm to fall into ;) ) My personal rule is that the DUT to antenna spacing must be significantly greater than the antenna structure's max overall dimension to believe the outcome. Additionally , the 40dB approximation may have been derived from an isotropic radiator in free space. I have a serious problem believing practical antennas like dipoles, which have been calibrated & defined in the far field , can give proper results when in a near field of any device being tested which may have near fields dominated by either magnetic OR electric radiator effects OR a strange and complex combination of both. I believe the "historical basis" of the part 15 method was defining VHF/UHF TV's local oscillator unintended emissions (conducted to) its receiving antenna. We've extrapolated a long way from that simple 100 foot far-field antenna to antenna coupling model. These comments are derived from (too) many hours of open field site experience in measuring pt 15 on CB and 2 way VHF radios in the '70's and special CB to TV interference studies with EIA TR-32 committee ~1976 when CB transitioned from 23 to 40 channels & receiver emissions limits were reduced from 32 dBuV/m to ~ 10.. Hey this is way too much fun at work. I have to get back to creating value for my customers. Best regards, Jerry Meyerhoff Principal Staff Engineer Motorola AIEG [Automotive & Industrial Electronics Group] of IESS [ Integrated Electronic Systems Sector ] 4000 Commercial Ave Northbrook Il. 60062 DISCLAIMER: This report represents the best opinions and analysis of the author based on the information available which may be subject to change without prior notice. The confidentiality of this info is everyone's responsibility. Any opinions implied or expressed in this work are solely those of the author . The suitability of this information for making decisions rests solely with the reader. JDM :-) 1/21/2000 -Original Message- From: rehel...@mmm.com [mailto:rehel...@mmm.com] Sent: Friday, January 21, 2000 5:50 AM To: emc-p...@majordomo.ieee.org Subject: Question on 15.31 I have not heard back fron the FCC on the following question. Does anyone have any insight into the answer? Thanks for your time, Bob Heller = -- Forwarded by Robert E. Heller/US-Corporate/3M/US on 01/21/2000 05:46 AM --- Robert E. Heller 01/19/2000 09:52 AM 3M Product Safety, St. Paul, MN 55107 76-1-01 EMC Laboratory Fax: 651-778-6252
Re: RE: EMC Circuit Board Design
What do you recommend other than metal can oscillators in item 5 below? Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com >>> "cetest" 01/21 9:50 AM >>> The most common mistakes carried out on PCB are: 1 Use 2-layer instead of multi-layer boards 2 Permit high F clocks to go trough long traces (> 4 Mhz) 3 Place connectors all over the surface instead of corner or edge 4 Let input and out lines of analog and power circuits run unfiltered to the cable 5 Use metal can oscillators (too high current drive) 6 Empty copper-fill grounded through thin traces (copper fill is of no use to emi) 7 Create 2 different ground planes that will compete for "real emc ground". 8 Regards, Gert Gremmen ce-test qualified testing == http://www.cetest.nl Do you know our CE/E mark True type Font ? http://www.cetest.nl/cettf.htm == >-Original Message- >From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf >Of rehel...@mmm.com >Sent: Friday, January 21, 2000 1:48 PM >To: emc-p...@majordomo.ieee.org >Subject: EMC Circuit Board Design > > > > > >Dear List-Members, > >I am requesting information/opinions/etc. on the following: > >When circuit boards are designed, what are the common mistakes that the >circuit board designers make regarding EMC (multi-layer boards in >particular)? > >You can respond to me directly but I would prefer a response to the list as >I believe that the question is of interest to many on this list-server. In >either event I will compile the responses and resend the compilation later. > >Thanks for your time, > >Bob Heller >3M Company > > > >- >This message is coming from the emc-pstc discussion list. >To cancel your subscription, send mail to majord...@ieee.org >with the single line: "unsubscribe emc-pstc" (without the >quotes). For help, send mail to ed.pr...@cubic.com, >jim_bac...@monarch.com, ri...@sdd.hp.com, or >roger.volgst...@compaq.com (the list administrators). > > - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Question on 15.31
Sounds to me as if they're being doubly cautious here. First they warn you not to make measurements in the near field. Then they use the 40dB per decade extrapolation factor to account for measurements taken in the near field (or perhaps the cross-over point between the near and far fields). If you look in a fields book, the equations for the electric field strength indicate that in the extreme far field, the electric field decays at a rate of 1/r, where r is the distance. This is where the 20dB per decade comes from by the relation of 20log(r1/r2). Since a decade is defined as the ratio of 10:1, 20log(10) is 20dB per decade. Getting back to the equation for electric field strength, the electric field decays at the rate of 1/(r*r) in the midrange region (somewhere between near and far field). This is where 40 db per decade comes from. The squared term in the logarithm expression comes out front as 2*20(r1/r2). Furthermore, in the extreme near field, the electric fi! eld decays at a rate of 1/(r*r*r). This equates to 60 dB per decade. In this case, the cubed term comes out front as 3*20log(r1/r2). If you look at Figure 3-1 and 3-2 in GR-1089, they switch from 20dB per decade to 60dB per decade at 15.9 MHZ, which is the crossover point from near to far field at 3 meters if you assume the crossover point to be lambda/pi. >>> 01/21 6:51 AM >>> Tha paragraphs are from FCC Part 15. === -- Forwarded by Robert E. Heller/US-Corporate/3M/US on 01/21/2000 05:49 AM --- Robert E. Heller 01/21/2000 05:49 AM 3M Product Safety, St. Paul, MN 55107 76-1-01 EMC Laboratory Fax: 651-778-6252 To: emc-p...@majordomo.ieee.org cc: Subject: Question on 15.31 I have not heard back fron the FCC on the following question. Does anyone have any insight into the answer? Thanks for your time, Bob Heller = -- Forwarded by Robert E. Heller/US-Corporate/3M/US on 01/21/2000 05:46 AM --- Robert E. Heller 01/19/2000 09:52 AM 3M Product Safety, St. Paul, MN 55107 76-1-01 EMC Laboratory Fax: 651-778-6252 To: rlafo...@fcc.gov cc: Roger D. Kuhn/US-Corporate/3M/US Subject: Question on 15.31 Mr. LaForge, I have a question concerning paragraphs 15.31(f)(1) and 15.31(f)(2). Paragraph 15.31(f)(1) concerns measurements above 30 MHz and at the bottom of the paragraph has a distance extrapolation factor of 20dB/decade. Paragraph 15.31(f)(2) concerns measurements below 30 MHz and at the bottom of the paragraph has a distance extrapolation factor of 40dB/decade. Why are there different extrapolation factors above and below 30 MHz? Thank you, Bob Heller 3M Company 651-778-6336 rehel...@mmm.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: 3 meter lab
Sounds like your goal is to get an idea of the relative impact that a change makes. For example, you have failed by 4dB at the test house and you want to try to mitigate the problem back at the office. You measure the product as it is, make a change to the product, and measure again for a delta (change in emissions). In this case, you would want to see a delta of at least 4dB. For this type of testing, I don't think you need a shielded room or an outside site. In the past, I have set up an antenna in a conference room to make measurements of this nature. I didn't use a ground plane. In fact, I have positioned the antenna as close as 1 meter from the product so the emissions from the product will rise above the ambient. The readings on the spectrum analyzer will not be accurate, but at least you can see the delta between changes. The delta that you observe should be relatively believable regardless of antenna position. This technique is not valid for pre-compliance te! sting however. In this case, you should strive for accurate readings. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com >>> 01/13 4:48 PM >>> Society, Our company is contemplating a 3m lab for preliminary emissions scans. We aren't looking for "submittable" results, but rather, a decent indicator of whether or not modifications to the EUT improve emissions. In your opinions, what is the minimum setup needed to achieve this? Without a proper ground plane and some sort of shielding on the walls, can a spectrum analyzer/antenna setup do any good? How are other company's labs set up? I've heard of people putting an open lab on their roofs. What kind of results do they get? Any opinions, experiences, or ideas are appreciated. Thanks, Brent - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
CASSPER
Greetings group, Has anyone actually used the CASSPER ambient cancellation system? According to the manufacturer, the receiver accepts inputs from two antenna; one placed at 3 or 10 meters from the EUT, and the second placed in the background (75-100 feet away). The receiver compares the input from both antenna and subtracts that portion of the EUT's signal that is attributed to the ambient. The end result is measurements taken in a "virtual chamber" environment. To make a long story short, the good people at CASSPER told me on more than one occasion that they would come out to my facility and give a demonstration of their product. However, after several follow-up calls over the coarse of several months, I have yet to see them. I am beginning to wonder if their product works as claimed. If anyone has any experience with the product, I would love to hear from you. Thanks. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
CE Countries
Greetings group, Does anyone have the latest list of countries in the European block who require the CE mark? Thanks. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 6531 Meridien Drive fax: (919)876-1817 Raleigh, NC 27616 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Transmission Line Theory
Greetings group, I am trying to draw a parallel between transmission line theory and radiated emissions. >From what I understand, a transmission line can be terminated at the source or >the load with an impedance that equals the characteristic impedance of the >transmission line itself. With this in mind, consider this scenario. A printed circuit card drives a clock signal down a trace on a backplane. The length of the backplane trace is long enough to be considered a transmission line. The driver on the printed circuit card is located within ½ inch of the edge connector (mating with the backplane) and is terminated with an impedance equal to the characteristic impedance of the backplane trace. However, the backplane trace is open ended (there is nothing connected to the end of the trace). Transmission line theory says the signal integrity will be maintained in this case. Now for the questions: (1) How much, if any, of the energy will be radiated into free space when it gets to the end of the open transmission line? To me, this looks like a monopole antenna. I don't have a very good understanding of antenna theory, so this could very well be an invalid assumption. (2) If radiation does take place as stated above in question (1), which is better for reducing the radiation, termination at the source or termination at the load of the transmission line, or does it matter? (3) If the characteristic impedance of the trace on the printed circuit card differs from the characteristic impedance of the trace on the backplane, how is this handled? Is a termination needed at each end in this case? I look forward to your responses. Thanks. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Precompliance Testing
Our division is in the process of constructing a new building. I have been told that I will be given a room in which to make pre-compliance radiated emissions measurements. However, ferrite tiles or cones are out of the question (I have been told that I can hang "chicken-wire" on the walls if I want to). Even though I am restricted in how much money can be spent, I have the luxury of designing in features as the building is being constructed. At a bare minimum, I think we should lay sheet metal or grid-wire on the floor after the concrete is poured. This ground plane should be grounded at each corner by ground rods. I am thinking that if there is no steel framework near the room, this may provide fairly good results. I would appreciate any recommendations on other cheap features that I can design in while the building is under construction. Also, what is the minimum size the room should be? How about power wiring in the walls and in the ceiling. Should any measures be taken to prevent radiated energy from coupling into power wiring? Perfection is not the key issue here: repeatability is. We have a local certified lab that I can compare my measurements with. Once the room is complete, I can repeat my measurements at the certified lab and develop the necessary correction factors. By the way, my product is dc powered shelf-level telecom equipment. Again, any advice will be appreciated. Thanks in advance. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
ESD Troubleshooting
Does anyone have a suggestion on how to troubleshoot ESD problems? Specifically, I am having a problem with contact discharge to a metal chassis. The first thing that comes to mind would be to check for ground bounce with an oscilloscope when the ESD gun is discharged. For example, I thought of grounding the oscilloscope probe to the ground plane and then probing the circuit ground (which is electrically connected to chassis ground at one point). However, I have been told the ESD gun will probably cause interference with the oscilloscope, e.g. energy coupled into the scope probe, etc. Any advice would be greatly appreciated. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Visible Light & EMC
This question sounds goofy, but here goes anyway Why doesn't visible light travel through solid objects (plastic, wood, etc)? Unless I've totally missed the boat, visible light is electromagnetic energy beginning at about 100,000GHz. So why doesn't it behave like electromagnetic energy in the radio spectrum? My guess is that it has something to do with the wavelength vs. the thickness of the object. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
UL 1950 Requirements for Operational Insulation
Clause 5.4.4 of UL1950, Third Edition specifies that in lieu of creepage and clearance distance requirements for operational insulation, the electric strength test for operational insulation (Table 18) can be used. Does anyone know how to calculate minimum distances between traces on a printed circuit board that would allow one to pass the dielectric test at a given voltage? Or has anyone taken any empirical data that would shed light on this topic? Also, would trace width have an impact on the dielectric test results? Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
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