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:
Dec. 25, 1990
Filed:
Aug. 15, 1989
Andrew M Mallinson, Billerica, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
An electric power measuring system wherein the current and voltage components are converted to respective digital signals which are multiplied and integrated to obtain a measurement of total power consumed. The current signal is developed by an A-to-D converter of the successive-approximation type, but differing from conventional such converters in employing two (or more) DACs in the feedback path where the analog feedback signal is developed for comparison with the analog current measurement signal. The two DACs are interconnected in such a way that the feedback signal is proportional to the square of the digital signal produced by the successive-approximation register (SAR). The final digital signal is developed by squaring the digital output of the SAR. The result is increased resolution at the low-level end of the scale, making it possible (in the particular embodiment) to achieve 1% accuracy at 1% of full scale, as well as 1% accuracy at 100% of full scale.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile