Ken Javor wrote: > Many test items fall in the category where some attached cables are long and > others are short. A computer with a power cord (long) and keyboard and > monitor and USB cables (short) is a perfect example. > > In this case you clearly run the test on the power cord from 0.15 - 80 MHz. > If the shorter cables are going to resonate at the higher frequencies then > that will happen, but you don't hit the shorter cables directly with the > lower frequencies. Incidentally, it should be noted that an 80 MHz
I read Annex B different, see case a) and the first example: Only the keyboard of the battery powered (!) device is to be tested with a higher starting frequency, the other examples start at 150kHz (German Translation of EN 61000-4-6:1996 + A1:2001). But you are right regarding field<->galvanic, the standard explicitly mentions field induced noise. And galvanically coupled noise has usually lower impedance. Nevertheless 61000-4-6 gives some indication of potential problems. No compliance issue, but interesting in terms of product quality. Oliver P.S.: top-posting makes it rather hard to follow your mails. -- 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 ______________________________________________________________________
