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:
Nov. 28, 1989
Filed:
Oct. 14, 1988
Scott H Hammond, Columbus, OH (US);
Ronald L Kirk, Findlay, OH (US);
Eric R Francis, Columbus, OH (US);
TransData, Inc., Tyler, TX (US);
Abstract
Method and apparatus for metering polyphase power sources in which cycles for each phase are sampled at each degree and converted to a binary representation of amplitude. Sampling commences with a zero cross-over and a first digital conversion provides range data for developing scaling factors which are retained in memory and for providing a selective gain for amplifying. The scaling factor and the range data then are multipled to develop a digital representation of the sample amplitude which may have as many as 21 significant bits plus a sign bit. These expanded data valuations for current and voltage then are selectively multiplied for each degree sampled to develop data available for generation of 12 electrical parameter outputs. Generally, six of these outputs will be elected by the user. Volt amperes are computed with respect to the zero cross-over events for both voltage and current samples, while quantities such as Q and var are developed by selective delayed multiplication of the unit degree samples.