Radius High Speed Lines
EMC Colleagues Has anyone had experience with using radius or rounding on high speed traces as opposed to chamfered 45 degree corners? Is there any real benefit for 1-5 nS rise time clock? I don’t think there is but maybe some may have other views. Thanks Darrell Locke Advanced Input Devices
RE: ELF (E and H) survey equipment
-Original Message- From: John Harrington [mailto:jharring...@f2labs.com] Sent: Monday, May 05, 2003 7:44 AM To: 'emc-p...@majordomo.ieee.org' Subject: ELF (E and H) survey equipment Does anyone know where I might be able to rent (and failing that purchase) some E and H field survey eqipment? I need it to range from sub 1Hz to 10kHz, to read E and H fields separately, and to be portable. Thanks John Harrington EMC Technical Manager F-Squared Laboratories That's an interesting task! I noticed that an old Stoddart NM-40A, which could measure to microvolts from about 20 Hz to 50 kHz, just sold on eBay for under $100. An old NM-40A, an active E-field probe and an H-field loop antenna could get you much of the way to doing your measurements. But, getting a bit more modern, you could also use a decent digital oscilloscope with FFT capability. That would cover from 10 kHz down to sub 1 Hz all by itself. Then, all you need are probes. Now here, I'm getting a little bit out of my range, so I invite any assistance or corrections. But it seems that you could get E-field by using something like a 41 rod counterpoise, which is electrically 1/2 meter. Use a very high impedance, bandwidth limited FET amplifier, calibrate the gain, and remember to add 6 dB for the 1/2 meter electrical length. For H-field, sub 1 Hz loops are a bit of a problem, but still a classical solution. You might try to get exotic with something like reading the voltage across a low resistance in series with a loop coil. You might try researching natural radio, where hobbyists have done a lot of work on low-noise, ultra low-frequency receivers and active antennas. Look at http://www.auroralchorus.com/natradio.htm Regards, Ed Ed Price ed.pr...@cubic.com NARTE Certified EMC Engineer Technician Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Is Our Specialty This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Vicor Power Supply Surge Immunity--- More testing...
Chris, Most MOVs are rated as 'Y' components. The manufacturer should be able to point you towards the appropriate agency information. You should also be concerned about the overvoltage affects of MOVs. Without some sort of thermal protection these devices can be very destructive. But, you need to be careful as the thermal devices can reduce the ability of the MOV to handle the necessary surge current. If your testing to EN61000-4-5, I have used the G4A and G5A thermal cut-outs from Thermodisk in series with the MOVs to reduce the affects of an overvoltage MOV. I know that there are limitations at placing MOVs to ground in some of the European countries. To get by you can place an MOV in series with a gas discharge tube (GDT). This reduces the amount of leakage current as the MOV (2 nf) is in series with the GDT (1 pf) resulting in a net impedance closer to the 1 pf of the GDT. The only side affect of this is a high voltage spike that results from the firing voltage of the GDT. This can be reduced with a LC filter after the MOV/GDT. This will require some tuning, but results in good protection that is capable of being used in multiple countries. There are some high-current diodes available from Sussex Semiconductor (www.sussexsemiconductor.com). The series is the AX4. These components are good up to 6 kA of 8/20 us transient current. I have used them in numerous products and they work well. They are expensive, but allot less cost than a series parallel string that is capable of the same performance. This probably more info than you really want, but if you want more information or discuss off-line, please let me know. Thanks, Bryan Cole Director of Engineering Product Safety Officer Control Concepts / Liebert Binghamton, NY T: 607.724.1352 extension 238 M: 607.624.8299 F: 607.724.0153 E: bryan.c...@control-concepts.com From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Friday, May 02, 2003 3:51 PM To: EMC-PSTC Internet Forum Subject: Vicor Power Supply Surge Immunity--- More testing... All, It seems that I could possibly pass the testing with a suppression device between Line and Chassis (probably from Neutral to chassis as well). Some experiments with TVS diodes that I have on hand have been promising. However, the diodes can't stand up to the multiple surges. i.e. I get passing test results until the TVS diodes are reduced to a broken pile piece of Silicon with all of its smoke let out. I'm also concerned with leakage current. My design already has a MOV from Line to Neutral; but I have heard that such components are taboo from Line to Chassis or Neutral to Chassis. Is there a Y rated TVS, MOV, Sidactor... out there? I'm tempted to try some 4700pF Y caps that I have around to see if they'll soak up the surge a little bit. 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: Chris Maxwell Sent: Friday, May 02, 2003 8:33 AM To: 'EMC-PSTC Internet Forum' Subject: Vicor Power Supply Surge Immunity Colleagues, Has anyone out there designed power supplies based on the Vicor 2nd generation converters? I have a design based on the Vicor FARM (Filter And Rectification Module) with two Vicor V300 series DC-DC converters behind it. I can't get this design through surge testing at 500V/250V, even though the data sheets for all of the modules claim immunity to 2KV/1KV. I'm not taking issue with the data sheets, Vicor makes good stuff. I just can't figure out what's up with this design. I have followed the spec sheet protection recommendations to the letter. I have suspected the Corcom 6ED8 filter in front could be causing ringing of the surge; but found that the failure occurs with or without the filter. The failure is very strange in that it: -Is load dependent. It seems that a higher load makes failure more likely -It happens at a random time, up to 17seconds after the surge. -Is characterized by the FARM's enable signal (which controls the V300s behind it) going low. -I can get some improvment (pass 500/250 but fail 1000/500) if I remove chassis ground from the FARM heatsink. It almost seems as though the surge is passing through the FARM to its grounded heatsink, along the way, maybe it is heating up some components, perhaps this heat takes a little while to get to the FARM's thermal shutdown circuit, which then dumps the enable signal (I know, really far fetched.) Maybe a layout problem? I'd appreciate any experience that others could share with this. Thanks, Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | This message
Re: ESD Gun verification
I can probably shed some light into this subject as I am the original designer of the Pelligrini target.In 1978/1979 I designed the coaxial target for waveform verification as our client, Dave Reynolds of Digital Equipment Corp., insisted on certain waveform adherence from our company (Experimental Physics Corp.) The original target used a BNC connector and it was designed to have better frequency response than the one DEC was using consisting of two parallel PC boards with the resistors between them (nick-named the ski-sled). DEC was working with the IEC committee on 801-2 which got ahold of the target provided to DEC. Even Mr. Pelligrini does not know why it was named after him! The target design transfered to Electro-Metrics when Experimental Physics solds its ESD product line to Electro-Metrics which conitnued to market the target for a few more years. The basic design evolved into the N connector and SMA connector variants. University of Berlin along with Dr. David Pommerenke extended the design with surface mount resistors to beyong the original design's 1 GHz limit. The new generation targets perform above 4 Ghz with special versions operating at near 10 GHz. Many other target designs have been made such as the tapered line target by Jon Barth, the NiCr film target by the late Hugh Hyatt (my former partner at Experimental Physics), the Transmission line target by Hugh Calvin etc. Hans Mellberg Engineering Manager BACL 230 Commercial Street Sunnyvale CA 94085 USA 408-732-9162 x38 408-732-9164 fax - Original Message - From: Jim Ericson jde...@nas.com To: emcpost emc-p...@majordomo.ieee.org Cc: drcuthbert drcuthb...@micron.com Sent: Saturday, May 03, 2003 4:09 PM Subject: Re: ESD Gun verification Dave: Yes. The current-sensing transducer that I built (Pelligrini Target) is per the Annex B drawings in EN 61000-4-2:1995 + A1:1998 +A2:2001. It has five paralleled 240 Ohm resistors arranged radially around the oscilloscope side to give 48 Ohms. On the ESD Gun side are twenty-five radially spaced 50 Ohm resistors to give 2 Ohms. Transconductance is 1 Amp/1 Volt into 50 Ohms. The present Standard requires a minimum 1 GHz bandwidth oscilloscope. I use a Pasternak Model PE7002-30 (DC to 2 GHz) 1 Watt Attenuator between the Pelligrini Target and the scope (voltage ratio of 32). The oscilloscope is a Tektronix 7104 with 7B10 time base, and a 7A26 dual-trace amplifier. I'll email a couple of photos to you (offline), and copy Mr. Pommerenke and Mr. Kinney. Regards, Jim Ericson Acme Testing Company j...@acmetesting.com - Original Message - From: drcuthbert drcuthb...@micron.com To: 'Jim Ericson' jde...@nas.com Sent: Friday, May 02, 2003 8:07 AM Subject: RE: ESD Gun verification Jim, I simulated this. I am assuming the circuit is a 2 ohm resistor to GND. If so, the series inductance must be 0.1 nH for the 2 ohm resistor. Does this sound right? I can do this with 25 paralleled 49.9 ohm resistors arranged radially around the input (discharge) point. Dave Cuthbert Micron Technology -Original Message- From: Jim Ericson [mailto:jde...@nas.com] Sent: Thursday, May 01, 2003 11:50 PM To: emcpost Subject: ESD Gun verification John: I faced the same problem about six years ago. I needed to do verification in between the expensive annual calibrations. I first explored the option of buying a Pelligrini Target. As I recall, the quotes I received were around $2000. That seemed outrageous, so I decided to build one myself. I'll bet it took me at least 3 days to make sense of those goofy mechanical drawings in 61000-4-2. If only they had included a photograph or good cross-section in the Standard! Anyway, I finally figured it out, translated the drawings into something understandable by a U.S. machine shop, and got all the brass parts fabricated locally. It took several in-process consulting sessions with the machinist, but I finally got all the brass parts done for around $300. Then, I purchased a $25 silver electroplating kit. It was like Science Fair time in my workshop! Some hours of painstaking soldering later, the target was completed. I mounted it over a specially-drilled hole in the brass wall panel of our anechoic chamber (you need a Faraday Cage of some sort, and this seemed the easiest). I did a quick check using our Tektronix 1 GHz analog oscilloscope ... and the risetimes and overall waveforms measured within spec! Then, I sent the target to Haefely-Trench for a calibration (against their standard Pelligrini target). The results were very, very close. Having performed many verifications at this point, my advice (if you want fairly accurate and repeatable results): 1.Make (or buy) something resembling the 61000-4-2 target. 2.Use a Faraday Cage. 3.Be aware how important the POSITION of the ESD Gun Grounding Strap is to
ESD gun verification
John: I faced the same problem about six years ago. I needed to do verification in between the expensive annual calibrations. I first explored the option of buying a Pelligrini Target. As I recall, the quotes I received were around $2000. That seemed outrageous, so I decided to build one myself. I'll bet it took me at least 3 days to make sense of those goofy mechanical drawings in 61000-4-2. If only they had included a photograph or good cross-section in the Standard! Anyway, I finally figured it out, translated the drawings into something understandable by a U.S. machine shop, and got all the brass parts fabricated locally. It took several in-process consulting sessions with the machinist, but I finally got all the brass parts done for around $300. Then, I purchased a $25 silver electroplating kit. It was like Science Fair time in my workshop! Some hours of painstaking soldering later, the target was completed. I mounted it over a specially-drilled hole in the brass wall panel of our anechoic chamber (you need a Faraday Cage of some sort, and this seemed the easiest). I did a quick check using our Tektronix 1 GHz analog oscilloscope ... and the risetimes and overall waveforms measured within spec! Then, I sent the target to Haefely-Trench for a calibration (against their standard Pelligrini target). The results were very, very close. Having performed many verifications at this point, my advice (if you want fairly accurate and repeatable results): 1.Make (or buy) something resembling the 61000-4-2 target. 2.Use a Faraday Cage. 3.Be aware how important the POSITION of the ESD Gun Grounding Strap is to these measurements ... especially to risetime measurements. I always take a photograph of the setup, including the shape of the Grounding Strap and where it is attached. If you don't do this, you'll get pretty wild variability between verifications. 4.Even a 500 MHz oscilloscope would probably be OK for verification. Just make certain that all setup parameters (including Ground Strap placement) are EXACTLY the same each time. That way, if the GUN happens to change, you'll at least know what to do next. Give me a call if you'd like a photo. Good luck! Jim Ericson Quality System Manager/Sr. EMC Engineer Acme Testing Company Acme, WA. 888-226-3837 j...@acmetesting.com - Original Message - From: John Harrington jharring...@f2labs.com To: emc-p...@majordomo.ieee.org Sent: Thursday, May 01, 2003 11:45 AM Subject: ESD gun verification Hello All Does any one have a quick and dirty (and hopefully cheap) way to verify the performance of an ESD gun. Please, no one suggest building the current sensing system described in the back of IEC 61000-4-2. I don't understand the drawings let alone have the workshop or materials to consider it. Although, I may pay someone to build it for me... I am desperate enough to consider buying something off the shelf (if I could find said shelf). All help appreciated John Harrington EMC Technical Manager F-Squared Laboratories --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD gun verification
I read in !emc-pstc that Jim Ericson jde...@nas.com wrote (in 004001c31052$499e9c40$83663fce@pavilion) about 'ESD gun verification' on Thu, 1 May 2003: Be aware how important the POSITION of the ESD Gun Grounding Strap is to these measurements ... especially to risetime measurements. I always take a photograph of the setup, including the shape of the Grounding Strap and where it is attached. If you don't do this, you'll get pretty wild variability between verifications. I strongly endorse that. It's not a 'ground strap', it's an open-wire transmission line in most cases. There is one product that has a more technically-defensible arrangement. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Vicor Power Supply Surge Immunity--- More testing...
All, It seems that I could possibly pass the testing with a suppression device between Line and Chassis (probably from Neutral to chassis as well). Some experiments with TVS diodes that I have on hand have been promising. However, the diodes can't stand up to the multiple surges. i.e. I get passing test results until the TVS diodes are reduced to a broken pile piece of Silicon with all of its smoke let out. I'm also concerned with leakage current. My design already has a MOV from Line to Neutral; but I have heard that such components are taboo from Line to Chassis or Neutral to Chassis. Is there a Y rated TVS, MOV, Sidactor... out there? I'm tempted to try some 4700pF Y caps that I have around to see if they'll soak up the surge a little bit. 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: Chris Maxwell Sent: Friday, May 02, 2003 8:33 AM To: 'EMC-PSTC Internet Forum' Subject: Vicor Power Supply Surge Immunity Colleagues, Has anyone out there designed power supplies based on the Vicor 2nd generation converters? I have a design based on the Vicor FARM (Filter And Rectification Module) with two Vicor V300 series DC-DC converters behind it. I can't get this design through surge testing at 500V/250V, even though the data sheets for all of the modules claim immunity to 2KV/1KV. I'm not taking issue with the data sheets, Vicor makes good stuff. I just can't figure out what's up with this design. I have followed the spec sheet protection recommendations to the letter. I have suspected the Corcom 6ED8 filter in front could be causing ringing of the surge; but found that the failure occurs with or without the filter. The failure is very strange in that it: -Is load dependent. It seems that a higher load makes failure more likely -It happens at a random time, up to 17seconds after the surge. -Is characterized by the FARM's enable signal (which controls the V300s behind it) going low. -I can get some improvment (pass 500/250 but fail 1000/500) if I remove chassis ground from the FARM heatsink. It almost seems as though the surge is passing through the FARM to its grounded heatsink, along the way, maybe it is heating up some components, perhaps this heat takes a little while to get to the FARM's thermal shutdown circuit, which then dumps the enable signal (I know, really far fetched.) Maybe a layout problem? I'd appreciate any experience that others could share with this. Thanks, Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD gun verification
I read in !emc-pstc that John Harrington jharring...@f2labs.com wrote (in 5777c7d14a69d411be4200a0cc746898493...@exchange.f2labs.com) about 'ESD gun verification' on Thu, 1 May 2003: Does any one have a quick and dirty (and hopefully cheap) way to verify the performance of an ESD gun. It's a major bugbear with that standard (and any ESD standard, I think). Any QD method will only give you very dirty answers. You might just as well not bother. No-one, AFAIK, really knows how the discharge current gets back to the gun. Even for an 'electrostatic' discharge, there must be a closed current path. Now think about those nanosecond pulses travelling along a metre or more of return cable. Inductance? What's that? (;-) Please, no one suggest building the current sensing system described in the back of IEC 61000-4-2. I don't understand the drawings let alone have the workshop or materials to consider it. Although, I may pay someone to build it for me... Don't. The amount of black magic you need even to make the official method work is immense, and you certainly can't qualify the current- sensing system without a lot of VERY costly test equipment. I am desperate enough to consider buying something off the shelf (if I could find said shelf). I'm not sure that you can even do that at a sensible cost, but I understand that there are a few specialist companies who will verify your gun for you. I don't have any names or URLs, though. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
ESD Gun targets
Jim, the Pelligrini Target spec in EN61000-4-2 is quite a challenge to meet. The 1 dB insertion loss delta from DC to 4 GHz to be exact. The simulation of my proposed PCB design shows that it can meet the spec and I have the equipment to verify this. I will build a few targets. Perhaps a few of you would like a target to use and to provide feedback. Who wants a target? Step right up and get your red hot Pelligrini targets! Dave Cuthbert Micron Technology From: Jim Ericson [mailto:jde...@nas.com] Sent: Saturday, May 03, 2003 5:09 PM To: emcpost Cc: drcuthbert Subject: Re: ESD Gun verification Dave: Yes. The current-sensing transducer that I built (Pelligrini Target) is per the Annex B drawings in EN 61000-4-2:1995 + A1:1998 +A2:2001. It has five paralleled 240 Ohm resistors arranged radially around the oscilloscope side to give 48 Ohms. On the ESD Gun side are twenty-five radially spaced 50 Ohm resistors to give 2 Ohms. Transconductance is 1 Amp/1 Volt into 50 Ohms. The present Standard requires a minimum 1 GHz bandwidth oscilloscope. I use a Pasternak Model PE7002-30 (DC to 2 GHz) 1 Watt Attenuator between the Pelligrini Target and the scope (voltage ratio of 32). The oscilloscope is a Tektronix 7104 with 7B10 time base, and a 7A26 dual-trace amplifier. I'll email a couple of photos to you (offline), and copy Mr. Pommerenke and Mr. Kinney. Regards, Jim Ericson Acme Testing Company j...@acmetesting.com - Original Message - From: drcuthbert drcuthb...@micron.com To: 'Jim Ericson' jde...@nas.com Sent: Friday, May 02, 2003 8:07 AM Subject: RE: ESD Gun verification Jim, I simulated this. I am assuming the circuit is a 2 ohm resistor to GND. If so, the series inductance must be 0.1 nH for the 2 ohm resistor. Does this sound right? I can do this with 25 paralleled 49.9 ohm resistors arranged radially around the input (discharge) point. Dave Cuthbert Micron Technology -Original Message- From: Jim Ericson [mailto:jde...@nas.com] Sent: Thursday, May 01, 2003 11:50 PM To: emcpost Subject: ESD Gun verification John: I faced the same problem about six years ago. I needed to do verification in between the expensive annual calibrations. I first explored the option of buying a Pelligrini Target. As I recall, the quotes I received were around $2000. That seemed outrageous, so I decided to build one myself. I'll bet it took me at least 3 days to make sense of those goofy mechanical drawings in 61000-4-2. If only they had included a photograph or good cross-section in the Standard! Anyway, I finally figured it out, translated the drawings into something understandable by a U.S. machine shop, and got all the brass parts fabricated locally. It took several in-process consulting sessions with the machinist, but I finally got all the brass parts done for around $300. Then, I purchased a $25 silver electroplating kit. It was like Science Fair time in my workshop! Some hours of painstaking soldering later, the target was completed. I mounted it over a specially-drilled hole in the brass wall panel of our anechoic chamber (you need a Faraday Cage of some sort, and this seemed the easiest). I did a quick check using our Tektronix 1 GHz analog oscilloscope ... and the risetimes and overall waveforms measured within spec! Then, I sent the target to Haefely-Trench for a calibration (against their standard Pelligrini target). The results were very, very close. Having performed many verifications at this point, my advice (if you want fairly accurate and repeatable results): 1.Make (or buy) something resembling the 61000-4-2 target. 2.Use a Faraday Cage. 3.Be aware how important the POSITION of the ESD Gun Grounding Strap is to these measurements ... especially to risetime measurements. I always take a photograph of the setup, including the shape of the Grounding Strap and where it is attached. If you don't do this, you'll get pretty wild variability between verifications. 4.Even a 500 MHz oscilloscope would probably be OK for verification. Just make certain that all setup parameters (including Ground Strap placement) are EXACTLY the same each time. That way, if the GUN happens to change, you'll at least know what to do next. Give me a call if you'd like a photo. Good luck! Jim Ericson Quality System Manager/Sr. EMC Engineer Acme Testing Company Acme, WA. 888-226-3837 j...@acmetesting.com - Original Message - From: John Harrington jharring...@f2labs.com To: emc-p...@majordomo.ieee.org Sent: Thursday, May 01, 2003 11:45 AM Subject: ESD gun verification Hello All Does any one have a quick and dirty (and hopefully cheap) way to verify the performance of an ESD gun. Please, no one suggest building the current sensing system described in the back of IEC 61000-4-2. I don't understand the drawings let alone have the workshop or materials to consider it. Although,
Re: ESD failure
I read in !emc-pstc that Ravinder Ajmani ajm...@us.ibm.com wrote (in of3726dba3.c9d3514a-on88256d19.007dd66b-88256d19.00802...@us.ibm.com) about 'ESD failure' on Thu, 1 May 2003: Any suggestions on what I should I try next. A grounded shield over the ASIC? It's being zapped by radiated energy, after all. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Theremal Resistance vs Thermal Impedance ...
There's plenty of references on the web. Here's one from Berquist. Best let you read it than me putting my own spin on it. http://www.bergquistcompany.com/tm_thermal_prop.cfm Regards, Doug McKean _ MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?page=features/virus This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org 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
TSB31-B: Any updates to the FCC Part 68 guidelines?
RE: Greetings All, Does someone in the group have an idea if the document TSB31-B (February 1998 Issue), Part 68 Rationale and Measurement Guidelines, will be updated to cross reference to the TIA standard, TIA-968-A, Technical Requirements of Terminal Equipment of the Telephone Network? Since the tests in FCC Part 68 became privatized, much of what was in Part 68 went into the TIA-968-A standard. In TSB31-B, I found the Tables 4.5-1 and 4.5-2, Test Requirement Matrix Interface Types, to be quite useful in determining what tests to perform. However, the tables use Part 68 section numbers instead of the TIA-968-A section numbers. I was able to make my own matrix to cross reference to the applicable TIA-968 sections, but eventually, new interfaces will added, and the TSB31-B will be outdated. Thanks in advance. Richard = Richard Georgerian Compliance Engineer Carrier Access Corporation 5395 Pearl Parkway Boulder, CO 80301 USA Tele: 303-218-5748 Fax: 303-218-5503 mailto:rgeorger...@carrieraccess.com * This e-mail transmission, and any documents, files, or previous e-mail messages attached to it may contain information that is confidential or legally privileged. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are hereby notified that you must not read this transmission and that any disclosure, copying, printing, distribution, or use of any of the information contained in or attached to this transmission is strictly prohibited. If you have received this transmission in error, please immediately notify the sender by telephone or return e-mail and delete the original transmission and its attachments without reading or saving them in any manner. Thank you. *
ESD Gun verification
John: I faced the same problem about six years ago. I needed to do verification in between the expensive annual calibrations. I first explored the option of buying a Pelligrini Target. As I recall, the quotes I received were around $2000. That seemed outrageous, so I decided to build one myself. I'll bet it took me at least 3 days to make sense of those goofy mechanical drawings in 61000-4-2. If only they had included a photograph or good cross-section in the Standard! Anyway, I finally figured it out, translated the drawings into something understandable by a U.S. machine shop, and got all the brass parts fabricated locally. It took several in-process consulting sessions with the machinist, but I finally got all the brass parts done for around $300. Then, I purchased a $25 silver electroplating kit. It was like Science Fair time in my workshop! Some hours of painstaking soldering later, the target was completed. I mounted it over a specially-drilled hole in the brass wall panel of our anechoic chamber (you need a Faraday Cage of some sort, and this seemed the easiest). I did a quick check using our Tektronix 1 GHz analog oscilloscope ... and the risetimes and overall waveforms measured within spec! Then, I sent the target to Haefely-Trench for a calibration (against their standard Pelligrini target). The results were very, very close. Having performed many verifications at this point, my advice (if you want fairly accurate and repeatable results): 1.Make (or buy) something resembling the 61000-4-2 target. 2.Use a Faraday Cage. 3.Be aware how important the POSITION of the ESD Gun Grounding Strap is to these measurements ... especially to risetime measurements. I always take a photograph of the setup, including the shape of the Grounding Strap and where it is attached. If you don't do this, you'll get pretty wild variability between verifications. 4.Even a 500 MHz oscilloscope would probably be OK for verification. Just make certain that all setup parameters (including Ground Strap placement) are EXACTLY the same each time. That way, if the GUN happens to change, you'll at least know what to do next. Give me a call if you'd like a photo. Good luck! Jim Ericson Quality System Manager/Sr. EMC Engineer Acme Testing Company Acme, WA. 888-226-3837 j...@acmetesting.com - Original Message - From: John Harrington jharring...@f2labs.com To: emc-p...@majordomo.ieee.org Sent: Thursday, May 01, 2003 11:45 AM Subject: ESD gun verification Hello All Does any one have a quick and dirty (and hopefully cheap) way to verify the performance of an ESD gun. Please, no one suggest building the current sensing system described in the back of IEC 61000-4-2. I don't understand the drawings let alone have the workshop or materials to consider it. Although, I may pay someone to build it for me... I am desperate enough to consider buying something off the shelf (if I could find said shelf). All help appreciated John Harrington EMC Technical Manager F-Squared Laboratories --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: D of C again
Quite the opposite. Compliance testing can only be done on the final production model. This obviously places compliance testing at the end of the pipeline. It is questionable, to say the least, to issue a DOC prior to final testing, so the DOC is not available till after final compliance testing. There is normally a several month lead time for publication of manuals, so the product introduction will be delayed by the amount of time necessary to get the manuals published. Manufacturers have very agressive (and often optomistic) development cycles. There is no extra time in the cycle to add a few weeks or months for publication and still meet introduction dates. These things have to run in parallel. John P. Wagner Regulatory Compliance Mandatory Standards AVAYA Regulatory Compliance Laboratory 1300 W. 120th Ave, Room B3-D16 Westminster, CO 80234-2726 Phone/Fax: (303) 538-4241 johnwag...@avaya.com From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Thursday, May 01, 2003 11:13 AM To: emc-p...@majordomo.ieee.org Subject: Re: D of C again I read in !emc-pstc that Wagner, John P (John) johnwag...@avaya.com wrote (in 4203D61676D0AE468AA5CEA90A891C130288F018@cof110avexu4.global. avaya.com) about 'D of C again' on Thu, 1 May 2003: I agree with Paul. It is usually very difficult to print the DoC in the users manual. Ordinarily, the manual is approved and goes to print before the final testing of the product and certainly before the DOC is signed. Is that a new law of nature? It seems that the system is running you, rather than the other way round. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
ESD troubles
Hi Ravinder! Really need more details to comment in detail. Consider the following, though: 1.Contact Discharge to the Horizontal Coupling Plane produces a large bloom of (mainly H-Field) radiation underneath the EUT. Could be on the order of 200 Volts/metre, depending on the spacing. Is the chassis open on the bottom? Can it be shielded? 2.Is the ASIC Integrated Circuit properly bypassed (very close) to its VDD pin(s)? 3.Are there any ribbon cables adjacent to the Horizontal Coupling Plane? Can they be re-routed? These are the first things I would check. Regards, Jim Ericson Acme Testing Company Acme, WA j...@acmetesting.com Hi ESD Gurus, I am having problem with a controller card which is failing contact ESD discharge at Negative 5 kV and below, but passes Positive contact discharge unto 8 kV, and air discharge of either polarity up to 15 kV. The card is mounted on an open metal chassis, and has DC input of 5V and 12V coming from a power supply. The ground of the card is directly tied to the chassis at several places. I am not discharging into the controller chassis, but l place the unit on my ESD table and discharge into the horizontal coupling plane, which results in the failure. Through my testing, I have isolated the problem to the main ASIC on the card. An earlier version of the same card passes the test, whose ASIC is built from the same CMOS process, but has a different processor core. It is difficult to determine which part of the ASIC logic is latching up. I have tried adding low value decoupling capacitors to power supply, but it has no effect on the problem. Any suggestions on what I should I try next. Regards, Ravinder Server PCB and Flex Development Hitachi Global Storage Technologies This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
ELF (E and H) survey equipment
Does anyone know where I might be able to rent (and failing that purchase) some E and H field survey eqipment? I need it to range from sub 1Hz to 10kHz, to read E and H fields separately, and to be portable. Thanks John Harrington EMC Technical Manager F-Squared Laboratories This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
