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. 30, 1977
Filed:
May. 24, 1976
Applicant:
Inventors:
Louis G Cox, Ottawa, CA;
Norbert L Kusters, Ottawa, CA;
Assignee:
Canadian Patents and Development Limited, Ottawa, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
324142 ; 324106 ; 324132 ;
Abstract
The differential thermal wattmeter for the ac/dc transfer of power includes a differential thermal converter as a 'sum and difference' multiplier, with both ac and dc voltage and current signals simultaneously applied to both heaters. DC feedback to the current input speeds up the response and maintains thermal balance between the heaters, so that the output meter becomes a null indicator. This reduces and can eliminate the need for quadratic response. The requirement for exact matching of the thermal converters is also eliminated by effective interchange of the heaters.