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. 14, 2025
Filed:
May. 19, 2023
Weltrend Semiconductor Inc., Hsinchu, TW;
WELTREND SEMICONDUCTOR INC., Hsinchu, TW;
Abstract
A motor system includes a brushless direct current motor, a back electromotive force (EMF) circuit, and a control unit. The brushless direct current motor includes first to third windings. The back EMF circuit is coupled to the first to the third windings. The control unit is coupled to the back EMF circuit for floating the first winding, energizing the second winding, and energizing the third winding prior to detect a zero-crossing event. The back EMF detects a duration of a freewheeling period of a back EMF signal of the first winding and a zero-crossing event. The control unit updates respective initial angles of respective driving currents of the first to the third windings according to the duration of a freewheeling period, and performs commutation according to respective updated initial angles of the respective driving currents of the first to the third windings upon detecting the zero-crossing event.