On 5/10/07, Peter P. wrote: > To sense high and low loads I have used two antiparallel diodes before. This is a great idea. Just put two diodes antiparallel to each other in series with the load. There will be no voltage across them when there is no current drawn. Any amount of current draw will place a 1.5v AC square wave across them. Make sure they can take the load. If you use diodes with a largish drop (1.8V) then you can drive an LED in a optoisolator for isolation if needed. Otherwise use clamping diodes and a comparator or a one shot (since it'll be pulsing). AC is considered a nasty, nasty service as-is, so you won't need to worry about the effects on the power from the slight voltage drop and "glitch" at zero crossing. -Adam -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ Interested in electronics? Check out the projects at http://ubasics.com Building your own house? Check out http://ubasics.com/home/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist