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:
Mar. 11, 1986
Filed:
Mar. 12, 1984
Frederick O Johnson, Monroeville, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
An electronic motor control system is taught herein which utilizes a tachometer check circuit. The tachometer check circuit is an electrical circuit which is interconnected with the output terminals of the tachometer. The circuit is utilized when the tachometer is at standstill to determine if the tachometer is functional, that is, is it internally correctly wired to produce an expected signal upon rotation. If such is the case, then motor start-up may take place. A second test is performed after motor start-up for determining if an appropriate amount of output voltage is being produced by the tachometer during the start-up phase. This is based on expected values of voltage during a short period of time after start-up. If such is not the case, the motor control system is disabled and the motor is stopped. The system is utilized for embodiments which include AC tachometers as well as DC tachometers used on unidirectional or bidirectional rotational systems.