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:
May. 23, 1989
Filed:
Dec. 11, 1987
Eddy So, Gloucester, CA;
Canadian Patents & Development Ltd., Ottawa, CA;
Abstract
A current-comparator technique for obtaining an instrument for accurate high voltage power measurements at very low power factors is described. The quadrature component of the load current is automatically balanced in the current comparator against a quadrature current obtained from a slave supply, thereby reducing the stringent high accuracy requirement of the instrument when used for measuring power at a very low power factors. The current-comparator-based instrument according to the present invention has an estimated accuracy with respect to its readings of better than 3 percent at 0.001 power factor, 1 percent at 0.005 power factor and 0.5 percent at 0.01 power factor and higher. It features an internal high-voltage active-divider and displays to indicate source voltage, current, power factor and reactance of the load, in addition to the power.