All, I've found something confusing in some automotive standards with regard to setup. >From CISPR 25(with similar language in ISO 11452-2) 6.4.2.5 Location of the load simulatorPreferably, the load simulator shall be placed directly on the ground plane. If the loadsimulator has a metallic case, this case shall be bonded to the ground plane. Alternatively, the load simulator may be located adjacent to the ground plane (with the case ofthe load simulator bonded to the ground plane) or outside of the test chamber, provided thetest harness from the EUT passes through an RF boundary bonded to the ground plane.
When the load simulator is located on the ground plane, the d.c. power supply lines of theload simulator shall be connected through the AN(s). The issue I see is that the load simulator is powered through the EUT's ANs, and many load simulators will have their DC return tied to chassis. If DC return is tied to chassis, and chassis is bonded to ground, and the input of the DC return AN is also bonded to ground(as shown in the standard), then you just shorted out the DC return LISN. So is the AN unnecessary here? Is the standard incorrectly shorting this out? Would just powering the load simulator separately prevent this issue? - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
