Staas & Halsey
Fail-safe control circuit
 A fail-safe control circuit which requires that all control units produce control signals to operate a controlled device. The control units receive a feedback signal used for comparing with the control signal. When the control signal and the feedback signal do not match, a power supply interruption or disagreement signal causes a relay to disconnect power to the controlled device placing the controlled device in a fail-safe state. 
501 Nec Home Electronics
Y G G G G
Y10S G05B G06F G06F G06F
additional inventional inventional additional additional
Tetsuji Yuji Tadashi Satoshi
Muto Fujimura Nose Baba