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:
Feb. 08, 1983
Filed:
Jun. 08, 1981
Richard James Cubbison, Jr, Littleton, CO (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Electronic battery feed circuits are connected across the communication pair, in parallel with the voice transformer, and serve as a dc path for loop current. These electronic battery feed circuits must provide both a low dc impedance to sink loop current and a high ac impedance so as not to shunt the ac signal away from the transformer. Prior art electronic battery feed circuits draw their bias current directly from the communication pair and this configuration tends to unbalance the line, provide too low an ac impedance, and provide too high a dc impedance. The subject electronic battery feed circuit obtains a low level bias current from the voice transformer and presents a low dc impedance to loop current. This particular circuit configuration eliminates hybrid balance problems and ac shunting of the voice transformer.