I read in !emc-pstc that Colgan, Chris <[email protected]> wrote (in <AE0F4BD08FEAD211895900805FE67B1F01425ABF@CAT>) about 'common mode immunity coupling units' on Tue, 5 Nov 2002:
>Please forgive my ignorance but can anyone tell me why above are designed to >give load and source impedances of 150 ohms? Because the characteristic impedance of a bit of wire a few cm above a ground plane is sort of, like, about 150 ohms approximately, on average, usually, sometimes. This should give you a healthy disrespect for much of the IEC61000-4 series of EMC standards.(;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
