The purpose of a LISN when testing for vehicular use is to simulate the common impedance between battery and fuse block.
There should be no power cycling ³behind² the LISN, because in the vehicle there is no switch between battery and fuse block other than the ignition switch itself. Therefore the power cycling device goes between the LISN output and the switched load. Ken Javor Phone: (256) 650-5261 From: Douglas Smith <d...@emcesd.com> Reply-To: Douglas Smith <d...@emcesd.com> Date: Fri, 10 Dec 2021 00:16:51 +0000 To: <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] unusual conducted emissions question Hi All, I have come across an unusual conducted emissions issue with a device where the impedance stabilization network for automotive testing itself causes a problem that will not let a class of equipment ever pass because of the network not the equipment itself. In this case, the power is cycled every second and the device that does that is behind the network as that is not being tested. The interrupted power goes through the network (12 Volts) and to the EUT. We got to the point where we replace the EUT with a DC load, 10 Ohm resistor in parallel with a 10 uF cap, to simulate the inrush current. That combination fails at the low end of the frequency spectrum a lot because the network, just a collection of L, C, and R is ringing at each power transition. Any thoughts? Seems like an artifact of the standard. The device cycling power is a lab circuit and not part of the test and so should be behind the network. Doug - ---------------------------------------------------------------- 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>
