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:
Mar. 30, 1993
Filed:
Mar. 23, 1992
Hidetake Nakamura, Tokyo, JP;
NEC Corporation, both of, JP;
The Tokyo Electric Power Company Incorporated, both of, JP;
Abstract
In a reactive volt-ampere-hour meter, either of a pair of electric signals representative of, respectively, an AC voltage and an AC current fed to a load has the phase thereof shifted by 90 degrees to produce a signal representation of a product of the two signals. A cumulative adder cumulates the resulting product signals. A first carry pulse and a borrow pulse are generated in the event of, respectively, an overflow and an underflow during cumulation and are fed to a first and a second up-down counter, respectively. The first up-down counter up-counts the first carry pulses and down-counts the borrow pulses and generates a second carry pulse when an overflow occurs. The second up-down counter up-counts the borrow pulses and down-counts the first carry pulses and generates a third carry pulse in the event of an overflow. An up-counter up-counts the second and third carry pulses from the first and second up-down counters, respectively. The count of the up-counter is representative of the result of cumulation of the absolute values of reactive power, i.e., the amount of reactive power.