Ken Javor wrote: > I disagree with what I perceive is being stated here - that if any portion > of a system has a connection to a long conductor, then all system-attached > cables must be tested down to 150 kHz.
I didn't write this. > The purpose of the Annex B wording is to allow for basic physics to be > applied to the limit - short cables are inefficient pick-up at low "pick up" _what_ - field? I'm writing about galvanically coupled disturbances. > frequencies. It is the length of the individual cable-under-test which > should drive the low-frequency cut-off limit. What about this: ...---long------[AE]-short-[EUT] Also very popular: [SMPS]--short--[EUT] | | '--GND PLANE---' The SMPS itself generates strong common mode noise. Let it be battery powered => no long cables anywhere. Strong commond mode voltages are widespread in industrial installations - especially at very low frequencies. Antitheft equipment can induce several volts in really small (1m) loops. Well - that's usually even below 150kHz... Oliver -- Oliver Betz, Muenchen - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
