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. 20, 1992
Filed:
May. 13, 1991
Mark W Feltis, Pullman, WA (US);
Luther S Anderson, Moscow, ID (US);
Schweitzer Engineering Laboratories, Inc., Pullman, WA (US);
Abstract
A breaker failure relay circuit is responsive to either a trip signal from a protective relay or a manual trip signal, as well as the current through a circuit breaker protecting a transmission line. The trip signal is applied to an edge triggered timer (28) having selected pickup and dropout times, and is also applied as one input to one OR gate (24). The circuit breaker current is applied to an overcurrent element (34), the output of which is applied to a reset input of the edge triggered timer (28) to reset and disable the timer and also as one input to another OR gate (30). The other input to OR gate (30) is the output of the edge triggered timer (28). The outputs of OR gates (24, 30) are applied to an AND gate (26), the output of which is applied to a second timer (32) and as another input to the one OR gate (24). The output of the timer (32), if and when it occurs, is used as a trip signal for a backup circuit breaker.