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:
May. 06, 2003
Filed:
Jul. 06, 2001
Joseph B. Mooney, Colfax, WA (US);
Schweitzer Engineering Laboratories, Inc., Pullman, WA (US);
Abstract
The system includes an enable signal applied to an output AND element. A comparator compares the voltage ratio of selected measured and calculated phase-to-phase or single phase voltages against a threshold value. An AND gate is responsive to a high signal from the comparator and indications of a three pole open condition, a single pole open condition for selected poles, and a loss of potential condition. A high output from the AND gate is applied to a timer, which produces a high output for a short period of time, which controls the output element. The output element provides a blocking signal for the protective elements under particular conditions and a permissive signal under other conditions.