RE: 1500 ohms 100 pF gun?
Mike, This is nothing new. Defense (India), it is even wild. IGT goes through same. Sudhakar From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Sosnoski, Michael Sent: Thursday, June 22, 2006 1:10 PM To: emc-p...@ieee.org Subject: RE:1500 ohms 100 pF gun? You guy's are lucky. In gaming --our requirements are Impervious to air discharge of 50Kv and contact at 27Kv. Every time I read of real standards (with any RC network)--I just wish. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Sudhakar Wasnik Sent: Thursday, June 22, 2006 3:00 PM To: Grasso, Charles; Conway, Patrick R (Houston); John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? Charles, It is not a question of right or wrong. It is about having logical rational explanation. Sudhakar From: Grasso, Charles [mailto:charles.gra...@echostar.com] Sent: Thursday, June 22, 2006 12:55 PM To: Conway, Patrick R (Houston); Sudhakar Wasnik; John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? So - does that mean that only unconventional engineers are right?? :-) Best Regards Charles Grasso Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Pager/Short Message: 3032042...@vext.com Email: charles.gra...@echostar.com; Email Alternate: chasgra...@ieee.org From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Conway, Patrick R (Houston) Sent: Thursday, June 22, 2006 1:47 PM To: Sudhakar Wasnik; John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? Ah, ha. Glad to find another engineer who thinks like I do - unconventional! anecdote- One time I visited a large, well respected IT company who was having an ESD problem with a new product. They could not release to production because they could not pass the ESD test. I made one change to their test procedure and they were able to pass. Nothing spectacular really, just a little applied unconventional thinking! I observed that their test engineer was doing the test and then discharging the EUT after each strike (battery operated EUT). The EUT passed each and every strike, but had an upset during his connection of the discharge wire. The discharge wire had no resistors in line. It was a straight dump to the horizontal coupling plane. I explained to the team, showed them the failures were only during post-test charge dump. I explained that the discharge event is uncontrolled. It could have more ore less rise time, more or less fall time, more or less peak amplitude. It is uncontrolled. If they wanted to test with that waveform- no problem. But it is not required for CE Mark (their target). Everyone was happy! Much rejoicing. Anyway- clear evidence that even the post-test discharge needs to be done correctly. And, evidence that more training is always a good thing! Best Regards, Patrick Conway, NCE. 281.514.2259 281.524.5473 (fax) p.con...@hp.com From: Sudhakar Wasnik [mailto:swas...@sandisk.com] Sent: Friday, June 23, 2006 3:14 AM To: Conway, Patrick R (Houston); John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? You are correct sir, The current flow is from higher potential to lower potential. So with repetitive zaps, the system accumulates the charge (potential) higher than Gun potential, So current will flow from Object being zapped to the Gun (Source). That's why standard requires removing the unspent charge from the EUT by manual discharge before applying next zap. If we consider this is same as lightening event, Then John is correct. It is mysterious even to think that the earth (Load) (earth) will pump current in to Clouds (Source) during repetitive lightening strikes. Sudhakar Wasnik Phone. : 408-542-2928 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Conway, Patrick R (Houston) Sent: Thursday, June 22, 2006 11:15 AM To: John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? q I wonder if Michael would explain how the discharge energy gets back from the equipment being zapped to the source. It seems very mysterious. q Actually, not mysterious at all. But does require some thinking outside of what is considered normal current flow. A simple experiment (real or just a thought experiment) can show the answer. Try this experiment- run a normal ESD test for table top equipment. For this, doesn't matter what test standard. Must use a battery operated EUT. Make sure the EUT power cord is disconnected. Now discharge the ESD simulator to the EUT one time. Discharge works fine, no observable variance in the ESD. But, continue to zap the device. Notice that the observable characteristics
RE:1500 ohms 100 pF gun?
You guy's are lucky. In gaming --our requirements are Impervious to air discharge of 50Kv and contact at 27Kv. Every time I read of real standards (with any RC network)--I just wish. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Sudhakar Wasnik Sent: Thursday, June 22, 2006 3:00 PM To: Grasso, Charles; Conway, Patrick R (Houston); John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? Charles, It is not a question of right or wrong. It is about having logical rational explanation. Sudhakar From: Grasso, Charles [mailto:charles.gra...@echostar.com] Sent: Thursday, June 22, 2006 12:55 PM To: Conway, Patrick R (Houston); Sudhakar Wasnik; John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? So - does that mean that only unconventional engineers are right?? :-) Best Regards Charles Grasso Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Pager/Short Message: 3032042...@vext.com Email: charles.gra...@echostar.com; Email Alternate: chasgra...@ieee.org From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Conway, Patrick R (Houston) Sent: Thursday, June 22, 2006 1:47 PM To: Sudhakar Wasnik; John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? Ah, ha. Glad to find another engineer who thinks like I do - unconventional! anecdote- One time I visited a large, well respected IT company who was having an ESD problem with a new product. They could not release to production because they could not pass the ESD test. I made one change to their test procedure and they were able to pass. Nothing spectacular really, just a little applied unconventional thinking! I observed that their test engineer was doing the test and then discharging the EUT after each strike (battery operated EUT). The EUT passed each and every strike, but had an upset during his connection of the discharge wire. The discharge wire had no resistors in line. It was a straight dump to the horizontal coupling plane. I explained to the team, showed them the failures were only during post-test charge dump. I explained that the discharge event is uncontrolled. It could have more ore less rise time, more or less fall time, more or less peak amplitude. It is uncontrolled. If they wanted to test with that waveform- no problem. But it is not required for CE Mark (their target). Everyone was happy! Much rejoicing. Anyway- clear evidence that even the post-test discharge needs to be done correctly. And, evidence that more training is always a good thing! Best Regards, Patrick Conway, NCE. 281.514.2259 281.524.5473 (fax) p.con...@hp.com From: Sudhakar Wasnik [mailto:swas...@sandisk.com] Sent: Friday, June 23, 2006 3:14 AM To: Conway, Patrick R (Houston); John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? You are correct sir, The current flow is from higher potential to lower potential. So with repetitive zaps, the system accumulates the charge (potential) higher than Gun potential, So current will flow from Object being zapped to the Gun (Source). That's why standard requires removing the unspent charge from the EUT by manual discharge before applying next zap. If we consider this is same as lightening event, Then John is correct. It is mysterious even to think that the earth (Load) (earth) will pump current in to Clouds (Source) during repetitive lightening strikes. Sudhakar Wasnik Phone. : 408-542-2928 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Conway, Patrick R (Houston) Sent: Thursday, June 22, 2006 11:15 AM To: John Woodgate; emc-p...@ieee.org Subject: RE: [JunkMail] 1500 ohms 100 pF gun? q I wonder if Michael would explain how the discharge energy gets back from the equipment being zapped to the source. It seems very mysterious. q Actually, not mysterious at all. But does require some thinking outside of what is considered normal current flow. A simple experiment (real or just a thought experiment) can show the answer. Try this experiment- run a normal ESD test for table top equipment. For this, doesn't matter what test standard. Must use a battery operated EUT. Make sure the EUT power cord is disconnected. Now discharge the ESD simulator to the EUT one time. Discharge works fine, no observable variance in the ESD. But, continue to zap the device. Notice that the observable characteristics of the ESD pulses become less severe. Smaller pop sound, plus the simulator tip has to get closer to the device to discharge. Eventually, you can no longer discharge to the EUT. So, what was happening? For all of those discharges what
RE: 1500 ohms 100 pF gun?
My bet's on capacitance Interesting thread --- kinda like déjà vu -- all these same conversations went on back in the mid 80's. Back then, there were lot's of specifications for ESD --- everyone had their own idea of what the capacitance and resistance values should be for a human discharge, with or without metal attached.. This settled into the IEC 801-2 values over time, but meanwhile, gun manufacturers made every version of discharge network known to man, from 20pf to 1000pf and from 0 ohms to 5k ohms IBM had a special tester (it was a secret at the time), that did high repetition rate testing and was coupled to radiating planes Wild stuff... I think they may still have some they'd sell cheap The Andy Hisch gun was very popular, and a lot of corporate standards were written around it, inlcuding those for companies like DEC and HP --- International standards took over eventually and the standardization began, which eventually forced most to the IEC model; however, other standards still exist -- most importantly for automotive and military. Not to mention device level testing that uses even different models. My 2 cents. Best Regards, Michael Hopkins Manager, Customer Technical Center Process Instruments Division Thermo Electron Corporation One Lowell Research Center Lowell, MA 01852 Tel: +1 978 935 9334 Direct +1 978 275 0800 Main +1 603 765 3736 Mobile michael.hopk...@thermo.com www.thermo.com/esd From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of John Woodgate Sent: Thursday, June 22, 2006 1:39 PM To: emc-p...@ieee.org Subject: Re: 1500 ohms 100 pF gun? In message 000801c69620$35d095e0$150bb...@colorado.linear.com, dated Thu, 22 Jun 2006, David Cuthbert dcuthb...@linear.com writes The return path for the charge (from the floating person) must be through displacement current. Oh, it IS magic, then. (;-) -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: 1500 ohms 100 pF gun?
In message 000801c69620$35d095e0$150bb...@colorado.linear.com, dated Thu, 22 Jun 2006, David Cuthbert dcuthb...@linear.com writes The return path for the charge (from the floating person) must be through displacement current. Oh, it IS magic, then. (;-) -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: 1500 ohms 100 pF gun?
Brent, I ran measurements a couple of years ago with myself discharging into a 2-ohm ESD target. I got the same results as sited in the email. A metal object in the hand really kicks up the initial current. The initial 300 ohm source appeared to be the arm followed by the body as 1200 ohms. SPICE was able to accurately model all of this. The human current rise time was faster than what our 3 GHz oscilloscope could measure. I would like to repeat these measurements using a 12 GHz oscilloscope. I did build a generator that accurately mimics the human waveforms using a bunch of leaded inductors and SMT caps and resistors. The return path for the charge (from the floating person) must be through displacement current. Dave Cuthbert Senior Test Engineer Linear Technology, Colorado Design Center NARTE Certified EMC Engineer, IEEE Member From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Brent DeWitt Sent: Thursday, June 22, 2006 9:47 AM To: Cortland Richmond; ieee pstc list Subject: Re: 1500 ohms 100 pF gun? I don't know about the Hish gun, but you can put that network together in a NoiseKen ESS-2000. The cap and resistor values are independently user changable. Brent DeWitt Everett, WA From: Cortland Richmond 72146@compuserve.com Sent: Jun 21, 2006 4:38 AM To: ieee pstc list emc-p...@ieee.org Subject: 1500 ohms 100 pF gun? Was looking for one for some military testing at work. I seem to recall that the Andy Hish ESD-255 used this network in one of its probes. Am I wrong? Cortland Richmond KA5S - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: 1500 ohms 100 pF gun?
I don't know about the Hish gun, but you can put that network together in a NoiseKen ESS-2000. The cap and resistor values are independently user changable. Brent DeWitt Everett, WA From: Cortland Richmond 72146@compuserve.com Sent: Jun 21, 2006 4:38 AM To: ieee pstc list emc-p...@ieee.org Subject: 1500 ohms 100 pF gun? Was looking for one for some military testing at work. I seem to recall that the Andy Hish ESD-255 used this network in one of its probes. Am I wrong? Cortland Richmond KA5S - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
