At 10:55 PM 3/6/2014, Josh Koffman wrote: >An extra 15% line voltage definitely shortens lamp life in a=20 >dramatic fashion. I used to have a slide rule put out by a bulb=20 >company (probably by Osram or Ushio) that let you calculate this. The rule of thumb that most lamp manufacturers used to give was that=20 bulb lifetime was approximately the delta V raised to the 12th=20 power. That is: input voltage / rated voltage raised to the 12th power. One can see very quickly just how much input voltage affects bulb lifetime! dwayne --=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 .