Derek Walton wrote:
>> I'm testing a product that's switching at 50 kHz, modulated by a 1 kHz signal. I'm getting a great deal of noise between 9 kHz to 13 kHz, I think is related. Specifically, it goes when I stop the modulation... Any ideas on ways to clean this up. Filtering seems to be effective, but HUGE! << A couple of thoughts: What's the stability of the switcher's control loop at 1 KHz? At 10 KHz? THat's the first thing I'd suspect. You may be driving it into an unstable region with modulation. Is this sine wave modulation? What happens when you change the switching frequency? The modulating frequency? It may be that this is a mixing product of the wave forms involved. Cortland ------------------------------------------- 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"
