The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 1978
Filed:
Mar. 16, 1977
Hitachi, Ltd., , JA;
Abstract
An audio- or low-frequency power amplifier comprises a pair of output transistors which are opposite in a conduction type to each other and connected in a complementary push-pull circuit configuration in which an impedance element is connected between the bases of the paired output transistors whose bases are adapted to be applied with an input signal while the output signal of the amplifier is derived from the coupled emitters of the output transistors. The amplifier further includes a current stabilizer transistor having a base-emitter junction across which a fixed bias voltage is applied and a collector, the current from which is supplied to the impedance element thereby to provide a bias voltage for the paired output transistors. A first resistor is connected between the emitter of the current stabilizer transistor and one electrode or pole of a first d.c. power source while a second resistor is connected between the emitter of the current stabilizer transistor and the other pole of the d.c. source, thereby to maintain constant the bias voltages applied to the paired output transistors.