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. 27, 2001
Filed:
Aug. 14, 1998
Michele Boscolo, Sottomarina, IT;
Marco Viti, Sesto S. Giovanni, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
A method of detecting the relative position of the rotor of a sensorless DC brushless motor driven in a tripolar mode includes the step of monitoring the voltage difference between the drive voltage that is applied to at least one winding of the motor and the voltage drop on a resistive portion of the drive current path through the same winding. The voltage drop may be detected between the two current terminals of an MOS power device of the driving bridge of the winding. The monitoring of the voltage difference is used to signal a perturbation from a pre-existing condition of correct synchronization of the phase switchings during a driving phase in a tripolar mode of the motor. Such information may be used by the driving system to switch to one of a bipolar mode, a unipolar mode or a tripolar mode with momentary drive interruptions, until restoring a correct synchronization condition and/or attain a correct rotating speed.