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. 09, 1983
Filed:
Aug. 19, 1981
Howard Sinberg, Coral Springs, FL (US);
Siemens Corporation, Iselin, NJ (US);
Abstract
A subscriber line interface circuit is disclosed for a 2-wire telecommunication subscriber line. The circuit includes a DC voltage source for supplying power to the subscriber line and an automatic power denial circuit for interrupting the power if an overload condition exists. The power denial circuit includes two resistors connected in series in one wire of the subscriber line and a transistor connected to respond to the voltage drop across these two resistors, thereby to sense an overload condition. A second transistor, controlled by the first transistor, is connected across one of the two resistors and is biased to be normally conducting when no overload condition exists. When excessive current flows through the two resistors, indicating an overload condition, the second transistor is cut off to deny power to the subscriber line.