Circuit for recognizing cyclically occurring pulse sequences

摘要

A circuit for recognizing cyclically occurring pulse sequences includes a counter controlled by a D-type flip-flop circuit to start counting the pulses in the pulse sequence when a specific pulse event occurs. The output of the counter is compared by a comparator with a preset number to provide an output via a gate if the specific pulse event occurs when the number of pulses counted by the counter is equal to the preset number. If the count rises above the preset number the comparator resets the flip-flop and no output is produced by the gate.