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. 04, 1977
Filed:
May. 27, 1975
Applicant:
Inventors:
David Latham Grundy, Saddleworth, EN;
John Thompson, Manchester, EN;
Assignee:
Ferranti, Limited, Hollinwood, EN;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
325319 ; 325409 ; 325413 ; 330 29 ; 330 98 ; 330139 ;
Abstract
Automatic gain control is provided in a two stage amplifier in which the first stage has a signal voltage gain related to its supply voltage and the second, or output, stage comprises an output transistor. The load of the output stage comprises an earphone in series with the supply. The supply for the first stage is taken from the junction of the output transistor and the earphone such that the gain varies inversely with the output of the earphone. The amplifier stages may be formed as a monolithic integrated circuit and contained in the housing of the earphone.