A microcomputer utilizing a crystal controlled clock and a power line responsive clock operates both the control system and into a safety timing means. The safety timing means can take the form of a pair of retriggerable monostable multivibrators that are operated to monitor the microcomputer along with a feedback circuit from a load control means. The feedback from the load control means senses the status of a safety switch means and provides the microcomputer with the ability to monitor and be monitored for safe operation.