Missing pulse detector

Claim 1

A missing pulse detector for producing an output signal whenever a pulse is missing from a regular, but variable frequency, pulse train supplied to the detector by accumulating a signal in a signal accumulating device during the interval between successively received pulses and analyzing the signal accumulated, said detector comprising a plurality of signal accumulating devices, reset means for each signal accumulating device, signal admission means for each signal accumulating device such that some of the signal accumulating devices have a higher rate of signal accumulation than the remainder, sequence control means controlled by the input pulse train and connected to control each of said reset means and each of said signal admission devices in such a manner that each signal accumulating device is reset by alternate pulses and then accumulates a signal for a time dependent on the duration of the intervals between successive pulses of the pulse train, and comparison means connected to compare the signal accumulated by one of the signal accumulating devices during one interval between successive pulses with the signal accumulated at a different rate by another one of the signal accumulating devices in a different interval between successive pulses and to produce said output signal if the signal accumulated by said one device differs from that accumulated by said other device in the sense opposite that which would result from the different rate of signal accumulation in equal intervals.