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:
Feb. 10, 1987
Filed:
Jun. 15, 1984
James R Hurley, Brookfield, WI (US);
Cooper Industries, Inc., Houston, TX (US);
Abstract
A measuring circuit for obtaining a mean square value of a power distribution line paramter and a process for obtaining a mean square value is disclosed. The measuring circuit and process exploit my discovery that an accurate measurement of the mean square may be closely approximated by sampling the power parameter an odd number of times greater than one during the power parameter cycle. When the power parameter is sampled an odd number of times (N) during its cycle aliasing errors due to the existence of odd harmonics above the Nyquist Frequency are minimized. As a result, the means of the most recent N sample values squared is very nearly equal to the true mean square value which would be produced by a continuous integration of the square of the power parameter during its period divided by the period. By sampling at a relatively low frequency, errors and circuit complexity are reduced, and the speed with which an acceptable mean square value is obtained is increased.