Television fault protection apparatus

Abstract From the Canadian patent

A phase-lock-loop circuit of a deflection apparatus generates a first signal at the horizontal frequency during normal operation. The first signal is coupled to a phase-control-loop circuit that maintains the timing of the deflection current in phase with the first signal. A fault protection circuit disables the generation of signal transitions in the first signal when a fault condition occurs. A circuit that detects the presence of transition edges in the first signal prevents the operation of the deflection output stage when the transition edges in the first signal are missing.