to reduce the peaks even more you mau double up your tants if that is possable with your parts/layout.
:-) Sorry i never got to doing the math with your curents and voltages.... work crept up on me and sent me to china...... Hellos to all from Shanghai. On 9/28/07, DJ Delorie <[EMAIL PROTECTED]> wrote: > > I got the new parts today. > > Redux: > > Adding 100uF electrolytic, swapping in 10u 25v 1206 ceramic did NOT > get rid of the buzzing, just reduced it a little. > > Swapping in 10u 16v 1206 tantalum with the 100u DID get rid of the > buzzing, both the low pitch and high. > > There's still 80mV P-P spikes on the line[*] at 8.3KHz (line refresh > rate) but that's 6X better than the 500mV ripple it used to have. > > Lesson: for heavy-noisy loads at audible frequencies, you need > sufficient non-ceramic decoupling before (or instead of) the ceramics. > > > [*] http://www.delorie.com/electronics/alarmclock/ > > > _______________________________________________ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user