Audio amplifier with modulated switching input for stored charge pulse generator

Claim 1

AN AUDIO AMPLIFIER COMPRISING A SEMICONDUCTOR SWITCHING DEVICE AT LEAST TWO TERMINALS, SAID DEVICE BEING OF THE TYPE HAVING AT FIRST STABLE IN WHICH A HIGH IMPEDANCE IS PRESENT BETWEEN SAID TERMINALS AND A SECOND STABLE STATE IN WHICH A LOW IMPEDANCE IS PRESENT BETWEEN SAID TERMINALS, SAID DRVICE BEING SWITCHED FROM ITS FIRST STATE TO ITS SECOND STATE IN RESPONSE TO A PREDETERMINED SWITCHING VOLTAGE APPLIED BETWEEN THE TERMINALS AND SWITCHED FROM ITS SECOND STATE TO ITS FIRST STATE IN RESPONSE TO A CURRENT BELOW A PREDETERMINED HOLDING CURRENT, A RESISTANCE CONNECTED IN SERIES WITH SAID DEVICE, MEANS FOR APPLYING A VOLTAGE ACROSS SAID SERIES COMBINATION WHICH IS GREATER THAN THE SWITCHING VOLTAGE, SAID RESISTANCE HAVING A VALUE SUCH THAT SWITCHING VOLTAGE, IS IN ITS SECOND STATE THE CURRENT FLOWING THERETHROUGH IS BELOW SAID PREDETERMINED HOLDING CURRENT, A CAPACITOR CONNECTED IN SHUNT WITH SAID DEVICE, SAID RESISTOR, SWITCHING DEVICE AND CAPACITOR FORMING AN OSCILLATING CIRCUIT WHICH OPERATES AT A PREDETERMINED FREQUENCY, MEANS FOR APPLYING A SIGNAL VOLTAGE TO BE AMPLIFIED TO SAID CIRCUIT TO MODULATE THE VOLTAGE ACROSS THE DEVICE IN ACCORDANCE THEREWITH TO FORM A PULSE TRAIN OF VARYING FREQUENCY, PULSE GENERATOR MEANS FORMING PULSES TO BE TRIGGERED BY SAID TRAIN OF PULSES TO PROVIDE OUTPUT FREQUENCY OF SAID OSCILLATOR, DEPENDENT UPON THE OUTPUT FREQUENCY OF SAID OSCILLATOR, AND MEANS FOR RECEIVING SAID PULSES AND AVERAGING THE SAME TO RECOVER THE AMPLIFIED SIGNAL VOLTAGE.