On Fri, Jan 30, 2015 at 3:32 AM, IVP wrote: > I'm not familiar with the linear characteristics of FET (ie how resistanc= e > changes as it turns on/off) but I'm willing to find out with you Ok, this is what I was thinking too. To do a proper calculation you have to integrate power losses over switching time. I will keep searching an equation as time allows... Josh --=20 A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .