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. 18, 1997
Filed:
Jun. 07, 1995
Eugene T Mullin, Phoenixville, PA (US);
Clifford J Bader, West Chester, PA (US);
Lockheed Martin Tactical Systems, Inc., New York, NY (US);
Abstract
Apparatus and method are provided for determining indicating if certain types of circuit failures have occurred in a D.C. motor circuit such as a locked rotor condition, a short-circuit or an open circuit. The method includes the steps of, and the apparatus involves, applying a voltage to two leads of the D.C. motor sufficient to cause motor rotation, determining if flyback exists, determining if back EMF exists, and, finally, if a back EMF does not exist and flyback does exist then indicating a locked rotor condition. However, if a back EMF does not exist and flyback does not exist then an indication is provided that either an open-circuit or short-circuit condition exists. The same apparatus and method can be used with a voltage not sufficient to cause motor rotation, although given this limitation only flyback can be detected, so that only an open-circuit or short-circuit condition can be indicated.