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:
Jun. 30, 1981
Filed:
Apr. 13, 1979
Tokyo Shibaura Denki Kabushiki Kaisha, Kanagawa, JP;
Abstract
In a method and apparatus for supervising a digital protective relaying system, a first type of electrical quantities in an electric power system, each having a certain magnitude, are detected, digitized and operated on in a data processing unit to check whether there is a fault in any of first input circuits adapted to receive the first type of electrical quantities. To check whether there is a fault in a second input circuit which normally receives a second type of detected electrical quantity having a substantially zero magnitude, one of the first type of electrical quantities is inputted into the second input circuit, and the data processing unit performs an operation on the output of the second input circuit and the outputs of the first input circuits except for that first input circuit corresponding to the one of the first type of electrical quantities which is inputted to the second input circuit.