Application of window comparator to majority operation

A fail-safe majority operation circuit capable of immediately reporting faults by utilizing multiple-valued signals is proposed, and the concrete configuration of the fail-safe majority operation circuit is clarified. The fail-safe majority operation circuit is defined as a circuit that has majority operation output signals and fault inspection output signals, never produces an output signal 1 in the event of any fault in its component devices when the operation output should be zero, and produces no wrong inspection output signals even if one input signal is erroneous. The fail-safe majority operation circuit is composed of fail-safe AND gates that have threshold values and are called window comparators