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:
Sep. 22, 2009
Filed:
Jan. 02, 2008
Sam Vermeir, Mechelen, BE;
Francois Laulanet, Brussels, BE;
Bart Decock, Haacht, BE;
AMI Semiconductor Belgium BVBA, Oudenaarde, BE;
Abstract
A circuit for determining a direction of rotation of an electric motor, the motor having asymmetry and/or eccentricity in a profile of back electromotive force as a function of angular position of a rotor with respect to a stator, the circuit receiving a signal representing the BEMF, and use the corresponding asymmetry and/or eccentricity in the signal to derive the direction of rotation. The signal representing the back emf can be generated by a control circuit. The control circuit can have a feedback loop regulator to generate a control signal (TL or TR) to control a current drive circuit () to control an amplitude of current (i) in the windings, the feedback loop regulator being arranged to compare the amplitude of the current (i) in the windings with a reference value (i), and use the control signal to provide the signal representing the back electromotive force.