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:
Jan. 04, 2000
Filed:
Mar. 30, 1999
Ramani R Kalpathi, Ann Arbor, MI (US);
Peter T Szymanski, Toledo, OH (US);
Dana Corporation, Toledo, OH (US);
Abstract
A method and circuit for detecting a locked rotor in a switched reluctance motor are provided. The method includes the step of measuring, at a predetermined frequency, the time required for a current in the motor to rise or fall between predetermined current levels to thereby obtain a plurality of sample rise or fall times. The method further includes the step of comparing first and second sample times of the plurality of sample times to obtain a time comparison value that is indicative of a change in position of the rotor. Because current rise and fall times are indicative of, and vary with, rotor position, a comparison of multiple rise or fall times may be used to indicate a change in position of the rotor and, therefore, whether the rotor is in motion or is locked. The method may finally include the step of comparing the time comparison value to a predetermined reference value that is indicative of a locked rotor.