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:
Oct. 11, 1977
Filed:
Aug. 20, 1976
Walter L Hinman, Jr, New Providence, NJ (US);
Russell W Gonnam, Morris Plains, NJ (US);
Westinghouse Electric Corporation, Pittsburgh, PA (US);
Abstract
Phase comparison relaying apparatus wherein the keying threshold levels at the local and remote ends of a protected power line section are each offset by a different value from the effective zero axis of the current waveform. One of the keying threshold values is set at a magnitude which will cause a trip response in the presence of low or medium magnitudes of outfeed current. The other keying threshold level is set at a magnitude which will cause a trip response in the presence of maximum magnitudes of expected outfeed current. The upper and lower current margin threshold levels are set to appropriately reflect the keying threshold level with which they are respectively associated. In addition, the transmmitter having the higher keying threshold level is located at that end of the protected line section where outfeed is expected.