On Mon, Aug 25, 2008 at 3:30 AM, Mike Harrison wrote: > Resistors don't fail short - even the standards for Intrinsically safe > equipment for use in flammable atmospheres state that resistors > can be assumed to be infallible as regards failure to > lower values. Not all resistors are equal. For IS (intrinsic safety) application, what you say can only apply to certain type of resistors (eg: metal film and wire-wound). Xiaofan -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist