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:
Jul. 26, 1994
Filed:
Mar. 23, 1993
Applicant:
Inventor:
Gyula Jakab, Nepean, CA;
Assignee:
Northern Telecom Limited, Montreal, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379413 ; 379399 ; 379412 ; 379402 ; 379404 ;
Abstract
A current limiting circuit in a battery feed arrangement provides a variable DC resistance for limiting subscriber loop current to a threshold value. The current limiting circuit also presents a low AC impedance so that no imbalance is introduced between tip and ring leads of the subscriber loop. The current limiting component is a low ON resistance power MOSFET in the ring side of the battery feed arrangement. The current limiting circuit is self protecting in the event of lightning strikes and AC power signals either induced or short-circuited.