Colin Constant wrote: > Sorry, you lost me with the last sentence. Why do I need a resistor > in series withthe incoming line followed by reverse Schottky diodes > to power and ground? To clip spikes and to limit the current thru the PIC protection diodes. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist