Dale, I believe what you are seeing is the effects of Ohm's law. The generator is required to have an output impedance of 2 Ohms or 10 Ohms. 4KV divided by 2 Ohms says the generator has the capability of providing a lot current into a short circuit. Even if you are speaking of signal lines requiring 40 Ohms series impedance, that's still 100 A. So if your load is 1/4 A, your load is presenting a high impedance to the source and should receive approximately the open circuit equivalent of the combination wave. Then a couple of "open circuits" in parallel is still an open circuit and should have a negligible effect.
It sounds like you have a case for a TCF. All you need is your Competent Body sign-off. Don Umbdenstock Sensormatic > ---------- > From: Dale Albright[SMTP:dale.albri...@flextronics.com] > Reply To: Dale Albright > Sent: Thursday, May 04, 2000 5:03 PM > To: wo...@sensormatic.com; emc-p...@ieee.org > Subject: RE: Surge > > > Richard, > > This was our intuitive thought too. However, I do not fully understand > the > discharge network and do not know, for instance, if the total joules > delivered to the coupler is independent of load or impedance. Does the > network always fully discharge? > > Today we spent some time to capture it. The following test was run on the > AC: One EUT was connected to the coupling/decoupling network. A digital > scope and fast Fluke probe was used to capture the voltage waveform at the > input of the EUT. The data was plotted. A second EUT was added in > parallel > to the coupling/decoupling network. The test was re-run (no moving the > probe) and the data was plotted. To my surprise, there was no change in > waveform. My expectation was to see no change in rise time but to see a > much faster decay time. > > A second test was attempted with a Fischer F-33-1 current probe. Not > successful. > > The subject EUTs pull approx. 1/4 Amp, no surge protection devices. The > test equipment is Keytek ECAT system (E4551 and E501A). > > We are proceeding to make a justification of the method (for these > particular EUTs ONLY) that the individual EUTs are not under-stressed. I > would like to seek additional input from the group. Unfortunately, most > senior staff at Keytek involved in the development of the system have > left. > If anyone knows of whereabouts, please email. Also if anyone has a > contact > at Schaffner or Haefely. > > Best Regards, > Dale Albright > > -----Original Message----- > From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] > Sent: Wednesday, May 03, 2000 12:11 PM > To: emc-p...@ieee.org > Subject: RE: Surge > > > > I assume that you mean applying the surge energy to multiple power ports > (or > I/O ports). Consider the energy produced by the surge generator and how > that > energy is dissipated in the EUTs. If there is one and only one port being > tested, would not the energy being delivered to that port be much higher > than if multiple ports were being tested at the same time? I think the > answer to your question is that you cannot test multiple ports since each > of > those ports would be under-stressed. > > Richard Woods > > ---------- > From: Dale Albright [SMTP:dale.albri...@flextronics.com] > Sent: Wednesday, May 03, 2000 11:14 AM > To: emc-p...@ieee.org > Subject: Surge > > > Group, > > A question came up today regarding testing multiple EUTs for surge > (61000-4-5). I spoke with the secretary of the subcommittee 77B > (Jacques > Delaballe) on this subject. We agree that: The method is not part > of the > standard; If the results are positive (EUT passes) then maybe OK; If > EUT > fails, then indeterminate. What are your thoughts? > > Regards, > Dale Albright > > > ------------------------------------------- > 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 > > > ------------------------------------------- > 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 > > > ------------------------------------------- > 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 > > ------------------------------------------- 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
