Means for increasing the catch range of a phase detector in an afc circuit

Claim 1

MEANS FOR PRODUCING A CONTROL VOLTAGE FOR STABILIZING THE FREQUENCY OF AN OSCILLATOR, COMPRISING A SOURCE OF SYNCHRONIZING PULSES, MEANS FOR DERIVING FROM SAID OSCILLATOR FIRST AND SECOND PULSATORY SIGNALS OF THE SAME FREQUENCY AS SAID OSCILLATOR, ELECTRONIC SWITCH MEANS HAVINGA CONTROL INPUT CIRCUIT AND A BIDIRECTIONAL CURRENT OUTPUT CIRCUIT, A CAPACITOR, MEANS CONNECTING SAID CAPACITOR AND SAID MEANS PROVIDING SAID FIRST PULSATORY SIGNAL SERIALLY TO SAID OUTPUT CIRCUIT, COINCIDENCE CIRCUIT MEANS, MEANS APPLYING SAID SYNCHORIZING PULSES AND SECOND PULSATORY SIGNALS TO SAID COINCIDENCE CIRCUIT TO PROVIDE A SWITCHING SIGNAL, WHEREBY SAID SWITCHING SIGNAL OCCURS ONLY UPON COINCIDENCE OF SAID SDYNCHRONIZING PULSES AND SECOND PULSATORY SIGNALS, MEANS APPLYING SAID SWITCHING SIGNAL TO SAID CONTROL INPUT CIRCUIT WHEREBY SAID OUTPUT CIRCUIT IS CONDUCTIVE ONLY UPON THE OCCURRENCE OF SAID SWITCHING SIGNAL, AND MEANS FOR DERIVING SAID CONTROL VOLTAGE FROM SAID CAPACITOR.