Hi there, David. I greatly respect your experience and would like to know more. I've used somewhere between thousands and tens of thousands of the=20 2003 & 2803 darlington drivers over the years - mostly driving relays=20 (JS1 & AZ2150) - but some driving displays with both LEDs and=20 incandescent bulbs. I have seen the odd failure but its always been=20 tracked down to one of the causes that I mentioned in my first reply=20 on this topic. I have, on occasion, used a TVS from the snubber common lead to=20 ground (rather than snubber common to Vdd) - but that was to achieve=20 a faster release time on the relays. FWIW - most of our stuff uses 5V Vdd with an unregulated supply=20 driving the relays - the unregulated supply comes from either 12Vac=20 or 24Vac (nominal +16 or +32 Vdc on the relay coils). The excess=20 coil voltage is dropped in the (series) indicator LED and either a=20 series dropping resistor *or* by applying PWM to the relay coils to=20 reduce the average voltage to the proper value. PWM is nominally 1ms=20 OFF and 4.1ms ON (~80%) - works very well. dwayne At 03:29 PM 12/11/2013, David VanHorn wrote: >Connecting the snubber common lead to vdd is not a good idea, glitches on >vdd at minimum, and vdd being fed unreg voltage thru the coils if Vcoil i= s >greater than vcc. Seen both of those done, outcomes were not happy. --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=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 .