Check circuit for combustion process control timer

摘要

A check circuit for checking operation of timers of a digital type combustion process control apparatus comprises flip-flops each having a preset terminal. The preset state of the flip-flops is inverted by an operation starting signal. The inversion is detected by a detector circuit the output signal of which is utilized for driving the control circuits for a combustion apparatus. The detector circuit is composed of a flip-flop circuit having input terminals applied with the operation initiating signal and the inverted output signal from the timer circuit.