> Is a relay closure/opening fast enough for your application?=20 Normally it is done by an SCR crowbar shorting the supply output, and then = relying on the supply over current protection to limit the current, or main= s protection fuse to blow. --=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 .