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. 22, 1986
Filed:
Sep. 01, 1983
Applicant:
Inventor:
John W Cook, Ipswich, GB;
Assignee:
British Telecommunications, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
364482 ; 1791 / ; 1791 / ; 324 64 ; 324 / ;
Abstract
An oscillating input signal is applied to the 4-wire input terminals which is monitored while the 4-wire output terminals and the 2-wire terminals are also monitored. This procedure is performed with a first known reference impedance connected across the 2-wire terminals and then repeated with a second reference impedance similarly connected. A plurality of input frequencies may be applied over the range of 400 Hz to 4000 Hz.