I see what you mean. The ³gun² has no ³trigger.² As I noted below, MIL-STD-331 required was an air discharge, but with a specific target in mind and if the target could not be reached by air discharge alone, a ³salient² was used as a guide, like they use a whisker to guide a simulated lighting strike to the desired point on the test sample. But the point remains that rise time was not of interest in MIL-STD-331B; only the total power it could delver to a specified load.
Ken Javor Phone: (256) 650-5261 From: "doug emcesd.com" <d...@emcesd.com> Date: Mon, 18 Feb 2019 20:29:09 +0000 To: Ken Javor <ken.ja...@emccompliance.com>, "emc-pstc@listserv.ieee.org" <emc-pstc@listserv.ieee.org> Conversation: [PSES] ESD network schematic Subject: Re: [PSES] ESD network schematic Hi Ken, You had made the note that contact discharge was used in the MIL test, but the circuit presented and all stds back then were only air discharge that I am aware of. ³so there the risetime doesn't matter and it is a contact discharge.² I may be misinterpreting what you mean by contact discharge. I am thinking of the modern type using a vacuum relay. Doug Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org From: Ken Javor <ken.ja...@emccompliance.com> Sent: Monday, February 18, 2019 12:22 To: emc-pstc@listserv.ieee.org Subject: Re: [PSES] ESD network schematic Doug, I don¹t understand this: ³Ken, the circuit posted does not contain any method for contact discharge.² MIL-STD-331B prefers air discharge when the discharge target can be attained (like a connector pin). If the target cannot be acquired via air discharge, then what they call a ³salient² can be attached to the target that makes direct contact with the ESD gun tip. The only requirement on the salient is that it itself is immune to ESD damage and it doesn't compromise the ability of the gun to deliver the required percentage of total stored potential (in gun charging cap) to specified loads. Only a 100 MHz BW o¹scope is required; this requirement is not about risetime; only about total power delivered. BTW, MIL-STD-331B is dated 1989; it supersedes MIL-STD-1399A, dated 1976. I don¹t have ³A², but it includes ESD. I don¹t know the date of original release, and whether that includes ESD. Ken Javor Phone: (256) 650-5261 From: "doug emcesd.com" <d...@emcesd.com> Date: Mon, 18 Feb 2019 18:23:18 +0000 To: Ken Javor <ken.ja...@emccompliance.com>, "emc-pstc@listserv.ieee.org" <emc-pstc@listserv.ieee.org> Conversation: [PSES] ESD network schematic Subject: Re: [PSES] ESD network schematic Ken, the circuit posted does not contain any method for contact discharge. We tested to 20+ kV for commercial products in the 1970s when I was at Bell Labs using a circuit similar to the one posted in this thread. I remember that lab built simulator and used it many times then. We also had home built lightning simulators we used long before the IEC or others got into that act for our own internal lightning standards. The Bell System was dealing with lightning well over a hundred years ago, probably before anyone else except possibly 1800s telegraph companies. That is too far back for me. Full scale ESD testing was certainly around at these high voltages by the time Touch Tone phones appeared. It was this research at Bell Labs that lead to the HBM model of ESD. We discovered that that model accurately predicted field hard failures of Touch Tone phones. Current HMM simulators are much more stress than our research at Bell Labs showed was necessary, at least for electronic circuits at the time, which were very susceptible. Doug Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org From: Ken Javor <ken.ja...@emccompliance.com> Sent: Monday, February 18, 2019 09:32 To: emc-pstc@listserv.ieee.org Subject: Re: [PSES] ESD network schematic Doug may be correct, but that 25 kV sounds like MIL-STD-331, and that is a test of electro-explosive devices, particularly the fuses that light them, so there the risetime doesn't matter and it is a contact discharge. The problem is, my copies only go back to 331B dated 1989, and from there to the present day it is 500 pF and 500 ohms, and none of the parasitic control in the drawing in this post. I was unsuccessful in going back further. Ken Javor Phone: (256) 650-5261 From: "doug emcesd.com" <d...@emcesd.com> Reply-To: "doug emcesd.com" <d...@emcesd.com> Date: Mon, 18 Feb 2019 06:17:26 +0000 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Conversation: [PSES] ESD network schematic Subject: Re: [PSES] ESD network schematic It is obviously jistvair discharge only. I suspect this is from the 70s, maybe earlier. The output rise time will be slow further indicating a very early design when they thought ESD had a ten ns risetime. Doug Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org From: Richard Georgerian <richa...@mesanetworks.net> Sent: Sunday, February 17, 2019 20:11 To: emc-pstc@listserv.ieee.org Subject: [PSES] ESD network schematic Greeting colleagues, I am trying to find out what standard or document the below ESD discharge network/ESD gun circuit comes from. It does not appear to come from either IEC 61000-4-2 or the MIL Standard. The Rs and Cs are the discharge network for a specific ESD waveform. The LS looks like the internal inductance of the ESD gun; the CH looks like the capacitance (maybe the parasitic capacitance of the ESD gun). The LH looks like the inductance of the ESD tip and the RH looks like the limiting resistor that is part of the ESD tip circuit. I cannot put a date as to when this schematic was made, so it could be something recent or from many years ago. Thank-you, Richard Georgerian Applications Engineer - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
