In message <[email protected]>, dated Wed, 15 Aug 2007, Ralph McDiarmid <[email protected]> writes:
>I?ve been informed that a 20V/m field when modulated to depth of 80% >produces a 36V/m field strength. Would someone explain how that >works. I?m puzzled. The amplitude modulation increases the amplitude as well as decreasing it. Modulation 'depth' suggests, wrongly, that it only decreases. 80% of 20 V/m is 16 V/m, so the maximum field strength during the modulation cycle is 36 V/m, and the minimum is 4 V/m. Note that all these numbers, if they are in a diagram, are peak values, but since all the r.m.s. values are 1/sqrt(2) of the peak values, the same numbers are valid if the peak unmodulated field strength is 28.3 V/m. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 ______________________________________________________________________
