Binary signal train keying ratio - method detects whether train exceeds or falls short of set keying ratio

摘要

A mean value with respect to time is produced for an input signal keying ratio. The input signal so controls the forward-backward input of a counter with an overflow blocking device, and a frequency switch switching between two timing frequencies (f1, f2), that during presence of pulses the counter counts in one direction, and also the timing frequency is applied to its clock input, while during spacings between pulses the counter counts in the opposite direction and the frequency (f2) is applied to its clock input. The ratio of the two frequencies (f1, f2) is the reciprocal of the set keying ratio. Information on the counter leading bit, which changes its state when the set keying ratio is exceeded, or not reached, is collected from the counter output.