I read in !emc-pstc that Ken Javor <[email protected]> wrote (in <[email protected]>) about 'A Different Kind of EMC Problem' on Tue, 12 Nov 2002:
>I am going to guess that the three devices you list as culprits did not have >any requirement to meet a conducted emission limit. See below. >Just like an SCR-based >light dimmer, they can chop the ac line with impunity. When I used to teach >seminars, and do demos in hotels, I learned not to rely on being able to use >AM radios in a hotel conference room - the large amounts of fluorescents and >other dirty loads, totally uncontrolled by any standards - often made AM >reception impossible. > [sigsnip] >> > >> >> I have three devices in my house that cause problems with AM radio band >> reception, but not due to emissions, >> >> In each case, the device adds modulation to strong AM signals, synchronous >> with the power line. >> >> The three devices are: 1. A stereo adaptor for a Beta VCR, CISPR13/EN55013 applies, and sets limits on conducted disturbances via the mains lead. The product would almost certainly not work with the VCR if its rectifier didn't have capacitors across it to eliminate rectification spikes. >2. A dishwasher >> with electronic controller, 3. An electric toothbrush charger. CISPR14-1/EN55014-1 applies, and sets limits on conducted disturbances via the mains lead. -- 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"
