Oliver Broad wrote: > When you measure without the regulator you measure the average of the > rectified waveform, which is still dipping down to zero between each half > cycle so you measure a lot less than peak, possibly less than RMS even? Yes. the average value of a half-sinewave is 2/pi, or 63.66% of the peak value. The RMS value is sqrt(2)/2, or 70.7% of the peak value. 40V (peak value, with regulator attached) * 63.66% = 25.46V (average value) -- Dave Tweed -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body