Fail-safe control circuit.

摘要

A fail-safe control circuit requires that all control units (11 - 1n) produce identical control signals (A1 - An) to operate a controlied device (4). The control units receive a feedback signal (C) used for comparing with the control signal (A1 - An). When the control signal and the feedback signal do not match, a power supply interruption or disagreement signal (D1 - Dn) causes a relay (8) to disconnect power to the controlled device (4) placing the controlled device in a fail-safe state.