At 09:32 AM 9/9/2003, llile@SALTONUSA.COM wrote: >Olin Elucidated: > > >You can make this even cruder and work better at low levels at the same >time. Lose the diodes and put the AC voltage onto the PIC pin, after the >clamping of course. Now sample fast enough in the PIC to do the max >function in software instead of with a diode. > >>I suppose a software RMS function would be the next trick. The negative >>excursion of the Current Donut's output is clamped off by input diodes (or >>the PIC if one wants to live dangerously!) so it would be inaccurate in >>regard to non-symmetrical signals. Naw - easy to fix. Connect the ends of the coil to 2 a/d input pins (one leg per a/d input). You might also need pull-down resistors from each a/d input to gnd as well. I'd also use schottky diode clamps as well. Read both a/d inputs - the input that is below ground most likely shows no reading while the other input shows the positive voltage at that instant. Minor problem: the 'gain' or 'slope' changes as the input protect diode of the negative input begins to conduct. Assume 0.2V forward voltage on the schottky diode and fix it in software . dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 19 years of Engineering Innovation (1984 - 2003) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics