Ken Javor <[email protected]> wrote (in <bf4f1089.2c189%[email protected]>) about 'When is a cable shield not a cable shield?', on Thu, 15 Sep 2005: >I have a problem with this as well. A non-magnetic shield material >protects against magnetic field radiation by providing a path for eddy >currents to flow in. The eddy currents flow in such a way as to cause >a magnetic field that opposes the originating field (Lenz' law). In >order for the eddy currents to have sufficient magnitude to cause field >cancellation, the shield must provide a very low impedance short
It's only open-circuit in one direction. In two other orthogonal directions, it's a closed circuit. But one open circuit is enough to kill it. Think 'balloon'. -- Regards, John Woodgate, OOO - Own Opinions Only. Deadlines are 90% of deadliness. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
