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. 21, 1984
Filed:
Feb. 10, 1983
Applicant:
Inventor:
Laurence L Sheets, St. Charles, IL (US);
Assignee:
AT&T Bell Laboratories, Murray Hill, NJ (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
17917523 ; 1791 / ;
Abstract
An arrangement to compensate for the leakage and biasing characteristics associated with the semiconductor crosspoints of a concentrator to allow accurate telephone subscriber loop measurements to be made through the concentrator. A compensation current is supplied which varies linearly with the applied test voltage according to a relationship that is determined adaptively just prior to the test so that the effects of device differences and temperature variations are minimized. The approach is extended to nonlinear compensation.