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:
Oct. 28, 2008
Filed:
Mar. 07, 2007
Applicant:
Kwang-hwa Liu, Sunnyvale, CA (US);
Inventor:
Kwang-Hwa Liu, Sunnyvale, CA (US);
Assignee:
Green Mark Technology Inc., Taipei County, TW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 6/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A circuit and a method for controlling the rotating speed of a brushless direct current (BLDC) motor are provided, whose goal is solving the stall problem encountered by conventional BLDC motors driven by pulse width modulation (PWM). The circuit includes a closed-loop control mechanism for adjusting the duty cycle of the motor current of the BLDC motor, thus controlling the rotating speed of the motor. The closed-loop control is based on the comparison of a signal proportional to the actual rotating speed and another signal proportional to the predetermined target rotating speed.