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. 23, 2008
Filed:
Nov. 16, 2004
Koji Hamaoka, Osaka, JP;
Yoshinori Takeoka, Shiga, JP;
Koji Hamaoka, Osaka, JP;
Yoshinori Takeoka, Shiga, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A method of driving a brushless DC motor includes operations of rectifying an AC voltage of an AC power source by a rectifier circuit to which a capacitor is coupled between its output terminals and the AC voltage of the AC power source is input; driving the motor by an inverter coupled to the rectifier circuit; detecting a rotor position of the motor by a position detector based on a motor back electromotive force or a motor current; estimating the rotor position by a position estimator when the rotor position is not detectable by the position detector; and controlling the inverter by a controller based on the rotor position detected by the position detector or the rotor position estimated by the position estimator.