Push-pull transistor amplifier provided with combined current and voltage negative feedback

Claim 1

IN A PUSH-PULL TRANSISTOR AMPLIFIER PROVIDED WITH COMBINED CURRENT AND VOLTAGE NEGATIVE FEEDBACK AND INCORPORATING AN INPUT TRANSFORMER HAVING A PRIMARY AND TWO SECONDARY WINDINGS, AND TWO TRANSISTORS WHICH ARE CONNECTED IN A SERIES CIRCUIT THROUGH WHICH DIRECT CURRENT CAN FLOW, WHICH TRANSISTORS HAVE INPUT CIRCUITS CONNECTED TO SAID TWO SECONDARY WINDINGS, RESPECTIVELY, THE IMPROVEMENT WHICH COMPRISES A COMMON OUTPUT CIRCUIT FOR SAID TRANSISTORS, SAID OUTPUT CIRCUIT INCORPORATING: (A) AN OUTPUT TRANSFORMER HAVING TWO PRIMARY WINDINGS CONNECTED TO OUTPUT CIRCUITS OF SAID TRANSISTORS, RESPECTIVELY, ONE OF SAID TWO PRIMARY WINDINGS BEING UNGROUNDED AND THE OTHER BEING GROUNDED AT LEAST INSOFAR AS ALTERNATING CURRENT IS CONCERNED; (B) A SERIES CIRCUIT COMPOSED OF A CAPACITOR AND A RESISTOR, SAID SERIES CIRCUIT INTERCONNECTING SAID TWO PRIMARY WINDINGS OF SAID OUTPUT TRANSFORMER; (C) A VOLTAGE DIVIDER CONNECTED ACROSS SAID UNGROUNDED PRIMARY WINDING; AND (D) MEANS FOR DERIVING FROM ACROSS A TAP ON SAID VOLTAGE DIVIDER AND GROUND A COMBINED CURRENT AND VOLTAGE NEGATIVE FEEDBACK VOLTAGE AND APPLYING THE SAME TO THE PRIMARY WINDING OF THE INPUT TRANSFORMER OF THE AMPLIFIER.