Output circuit of power amplifier

Abstract

Abstract PURPOSE:To reduce number of diodes in a bias circuit to make compensation voltage small and enable non-adjustment of the bias circuit. CONSTITUTION:In a circuit where a push-pull circuit is organized by transistors Q1, Q3, Q5, Q2, Q4, Q6 and it is devised to take out the output from a load resistor R1, Q1, Q2 of both Darlington first stage of the push-pull are arranged in the reverse polarity and are connected to the following stage through a diode D1 and C2 for temperature compensation of them. Also, to these Q1, Q2 and the following stage, bias voltage is applied with the constant current power supply Ic, and input is introduced directly to Q1, Q2. Through this arrangement, even when the temperature of the transistors and their vicinity will be changed, alway approximately constant idling current should be flow, runaway of transistors is prevented, there is no need to vary the idling current, and non-adjustment of the bias circuit become available.

Inventors

• 👤 Yoshio Miyazaki

Bibliographic Details