Frequency selective detector circuit

Abstract From the Canadian patent

Abstract A frequency selective detector circuit is useful as a high/low pass detector or as a bandpass detector. The high/low pass detector comprises a pair of digital missing pulse detector circuits or resettable one-shot multivibrators that are connected together in cascade between a source of input pulses and the detector circuit output. The timing interval of the first missing pulse detector circuit in the cascade is less than the timing interval of the second missing pulse detector circuit in the cascade. By combining two such circuits to supply their outputs to a coincidence gate, a bandpass detector circuit results.