Electrical power system with fault tolerant control unit

摘要

A high reliability electrical power system is provided with a microprocessor-based control unit which maintains power output and performs control functions for the system which is driven by the power system. A self locking feature prevents the transmission of potentially erroneous control signals if a component of the system being controlled or the control unit fails. The control unit conducts a series of self-test routines which result in the generation of digital key words. If the correct key words are generated and the other circuits of the control unit are operating properly, the control unit output remains operative. If the self test routines detect a failure in the system being controlled or the control unit or if a failure occurs in one of the control unit output circuits, the control unit output is locked into a predetermined state.