At 11:00 AM 12/26/2011, Electron wrote: >1) A nice sinusoid comes from a transformer. > >2) It passes through a diodes bridge, so it's rectified now. > >3) My PIC32 shorts it through an NPN transistor, effectively=20 >exploiting the inductance of the secondary of the transformer. Yes,=20 >it can withstand the resulting voltage spikes. :) Side question: are the diodes that make up the bridge rectifier fast=20 or ultra-fast diodes? If not, you will be seeing significant losses=20 from those diodes. dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .