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:
Feb. 13, 1979
Filed:
Apr. 27, 1978
Applicant:
Inventors:
Shigeki Inoue, Toyokawa, JP;
Isao Akitake, Yokohama, JP;
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F / ;
U.S. Cl.
CPC ...
330260 ; 330109 ; 330294 ; 330304 ;
Abstract
An equalizer amplifier of a negative feedback type comprises a common-emitter amplifier, an emitter follower amplifier cascade-connected thereto, and a negative feedback network connected between the output terminal of the emitter follower amplifier and the input terminal of the common-emitter amplifier with its negative feedback level increased as the frequency increases, wherein an inductance element is connected in series with the negative feedback circuit to attenuate harmful signals whose frequencies are higher than those of audio signals, thereby making large the ratio of signal to noise in the equalizer amplifier.