I read in !emc-pstc that Scott Douglas <[email protected]> wrote (in <[email protected]>) about 'Primary Power On PCB's' on Fri, 9 Apr 2004:
>Second question is about a linear power supply with a very large toroid >transformer (600+ VA) and two very large (call them garbage can sized) caps. >This power supply fails Harmonics when tested to EN 61000-3-2; it is almost >double the limit for harmonics currents. Short of going to a switcher, are there >any solutions that are not extreme to make the supply pass the test? What is the product? Which Class in 61000-3-2 do you think applies? This is very important, because the test conditions affect the harmonic current values considerably. The only simple method of reducing the harmonics is to add resistance (or even better, inductance if you can afford it) in series with the rectifier. -- Regards, John Woodgate, OOO - Own Opinions Only. The good news is that nothing is compulsory. The bad news is that everything is prohibited. http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ 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://www.ieeecommunities.org/emc-pstc
