I think it is more than coincidence that the two examples cited were not really engineers, but scientists. Brilliant scientists tend to crest early, whereas good engineers, like fine wine, just get better.
But the coincidence I see is between the examples of scientists and the science of ESD. Just the fact that there have been so many waveforms and so many refinements to the test procedure lead me to the conclusion that ESD is a science, it is not mature enough to be termed an engineering discipline. > From: "Conway, Patrick R (Houston)" <p.con...@hp.com> > Date: Fri, 23 Jun 2006 11:22:33 -0500 > To: "Grasso, Charles" <charles.gra...@echostar.com>, "Sudhakar Wasnik" > <swas...@sandisk.com>, "John Woodgate" <j...@jmwa.demon.co.uk>, > <emc-p...@ieee.org> > Subject: RE: [JunkMail] 1500 ohms 100 pF gun? > > Good question. > Two data points: Heaviside and Einstein. > Both were unconventional in their thinking. > Both were initially received with skepticism. > But both were right. > However, Heaviside was brilliant when young, but quite the crack-pot when he > got older. > Also, Einstein's major contributions were all out in public by the time he was > 30 yrs old. > > So, the conclusion I draw is that yes, unconventional thinkers are right, but > only when they are young. > > Rats. Too late for me!! > > > Best Regards, > Patrick Conway, NCE. > > 281.514.2259 > 281.524.5473 (fax) > p.con...@hp.com > > -----Original Message----- > From: Grasso, Charles [mailto:charles.gra...@echostar.com] > Sent: Friday, June 23, 2006 3:55 AM > 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 > > -----Original Message----- > 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 > > -----Original Message----- > 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 > > -----Original Message----- > 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 was the "Return path", since the EUT cord was > removed? > Why is it that the simulator no longer discharges? > Those last two questions have the same answer. > > Maybe the normal loop model, > "source-destination-return-to-source", does not apply? > > Hmm. > > Best Regards, > Patrick Conway, NCE. > > 281.514.2259 > 281.524.5473 (fax) > p.con...@hp.com > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. 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