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. 14, 1991
Filed:
Aug. 10, 1990
Karl Konecny, Portland, OR (US);
Synektron Corporation, Portland, OR (US);
Abstract
A motor control circuit for a switched reluctance motor which includes a rotor and a plurality of stator coils, and a driver circuit for energizing the coils in sequence, includes a current sensing resistor for detecting a signal proportional to the current in the coils and a slope detector for detecting the rate of change of the current signal with respect to time over predetermined time intervals during which the voltage in the coils is dominated by a term representing back EMF. A variable oscillator is responsive to an integrated output of the slope detector for generating a timing signal for the driver circuit. When the voltage across the coils is dominated by the back EMF term, the current should be substantially constant, but when the rotor is out of phase with the driver circuit, the current signal during this time has a substantially linear slope which is either positive or negative depending upon whether the rotor is leading or lagging the driver circuit.