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:
Sep. 28, 1999
Filed:
Jun. 30, 1997
John H Blakely, Asheville, NC (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A method and apparatus is disclosed for three phase sensing of a polyphase distribution system to provide true RMS signal monitoring capabilities. Each current transformer is provided with a rectifier and a separate burden to not only provide accurate signal representation of the true RMS currents in each phase, but also provide a DC voltage supply to thereby self-power the circuit. Two configurations are disclosed, one in which two CTs sense all three phases. In this configuration, two phases of the three phase system are used as a single primary winding in each current transformer such that each current transformer produces a voltage representation of a sum of two phase currents. A second configuration discloses the use of a current transformer for each phase. In both embodiments, by providing a separate burden and rectifier for each CT, true RMS signal characteristics can be extracted from the produced discrete signals, while at the same time providing a DC voltage supply for self-powering the circuit.