Michael Rigby_Jones wrote: > These may be usefull: > > http://www.irf.com/technical-info/an937/an-937p10.htm > http://www.discovercircuits.com/PDF-FILES/fetssr.pdf > > Mike Mike Yes - both excellent references. I now have three viable options I think. Thanks! Alan -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.