Ringing circuit with means preventing damped oscillations

Claim 1

A RINGING CIRCUIT COMPRISING: AN INITIALY CONDUCTIVE ELECTRONIC VALVE HAVING AN INPUT ELECTRODE AND A PAIR OF OUTPUT ELECTRODES; A RESONANT CIRCUIT RESPONSIVE TO CURRENT FLOW THROUGH SAID ELECTRONIC VALVE; MEANS FOR APPLYING A PULSE OF PREDETERMINED DURATION TO SAID INPUT ELECTRODE FOR ALTERING THE CONDUCTIVITY OF SAID ELECTRONIC VALVE FOR SAID PREDETERMINED DURATION DURING WHICH FULL CYCLE OSCILLATIONS ARE PRODUCED IN SAID RESONANT CIRCUIT; AND MEANS INCLUDING A FIRST DIODE CONNECTED BETWEEN SAID RESONANT CIRCUIT AND ONE OF SAID OUTPUT ELECTRODES, THE OTHER OF WHICH IS COUPLED TO A SOURCE OF UNIDIRECTIONAL POTENTIAL, AND A SECOND DIODE CONNECTED BETWEEN SAID ONE OUTPUT ELECTRODE AND GROUND POTENTIAL FOR SHORT CIRCUITING SAID RESONANT CIRCUIT AFTER THE EXPIRATION OF SAID PREDETERMINED DURATION, THEREBY DISCONTINUING SAID FULL CYCLE OSCILLATIONS.