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:
Aug. 25, 1981
Filed:
Mar. 15, 1979
Applicant:
Inventor:
Peter F Blomley, Bishop's Stortford, GB;
Assignee:
International Standard Electric Corporation, New York, NY (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03F / ;
U.S. Cl.
CPC ...
1791 / ; 179 / ; 179 / ; 1791 / ;
Abstract
A four-transistor bridge amplifier is adapted for use as a bidirectional speech amplifier between a telephone line and an electronic telephone subscriber's instrument. The amplifier is powered from the line and includes two-transistor sections, one or other of which functions dependent on line polarity. The output of the amplifier to the subscriber instrument is taken across a resistor connected between the transistors such that the output always has the same relative polarity whatever the line polarity.