I read in !emc-pstc that don_macart...@selinc.com wrote (in <OF26C3658E. a50db9b6-on88256cbb.00613...@selinc.com>) about 'Unity Power Factor' on Mon, 27 Jan 2003: >Why are so many U.S. manufacturers using Unity Power Factor correctors in >low wattage power supplies? > >Are there any U.S. requirements for Harmonics or they just trying to meet >CE mark requirements (devices rated > 75W)?
Well, there's IEEE519. But there's also 'hot neutrals', due to 3rd (9th, 15th...) harmonic currents adding in-phase in the neutral, which occurs in USA whereas the other European problems with harmonics don't occur so much, because the distribution system is different. Countries outside Europe are gradually adopting IEC 61000-3-2 under emission regulations. -- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org 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"
