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. 02, 1982
Filed:
Sep. 22, 1980
Ramon C Chea, Jr, Monroe, CT (US);
International Telephone and Telegraph Corporation, New York, NY (US);
Abstract
A subscriber line interface circuit is described wherein current supplied to a telephone subscriber line from a shared voltage source such as a DC/DC converter is regulated thereby permitting a regulated line current to be supplied to a plurality of line circuits from a single shared voltage source. In accordance with the present invention, both the dc line feed and the ac transmission requirements of a subscriber line interface circuit for a telephone exchange are implemented in a single circuit incorporating ac and dc impedance synthesis techniques. A significant reduction in the heretofore required expensive and bulky discrete components of the subscriber line interface circuit is achieved.