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:
Mar. 18, 1980
Filed:
Dec. 29, 1978
Applicant:
Inventor:
Barry S Bosik, Parsippany, NJ (US);
Assignee:
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 77 ; 179 / ;
Abstract
A line feed circuit for a telephone subscriber loop is disclosed which can be used to supply constant current to the subscriber loop. An operational amplifier, operating in its direct current mode, is used to maintain the current constant. The same operational amplifier, operating in its alternating current mode, magnifies the value of a capacitance bypassing the line feed circuit. In this way the alternating current impedance of the line feed circuit is maintained at a very low level.