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:
Nov. 09, 1976
Filed:
Sep. 08, 1975
Applicant:
Inventor:
Lloyd A Tarr, Elmhurst, IL (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03G / ;
U.S. Cl.
CPC ...
179 / ; 330 29 ;
Abstract
An automatic gain control circuit for limiting the acoustical power to the receiver portion of a telephone operator's headset. The circuit provides means whereby the maximum level of acoustic energy output a telephone operator is subjected to is controlled to levels well below those where damage to the ear can occur. Features of the invention include the use of diodes in the feedback path of the an amplifier whereby DC currents control the conductivity of the diodes to control the amplifier gain, and a pair of such circuits in phase opposition serve to cancel control current effects on the signal path.