Not opto, but how about a transformer? Put the contacts on the secondary winding and drive the primary. When the contacts close, the primary current increases. Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available! -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist