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:
Aug. 11, 2009
Filed:
Apr. 23, 2007
Hsing-cheng Yu, Hsinchu County, TW;
Hsing-yu Lin, Taichung County, TW;
Shir-kuan Lin, Hsinchu, TW;
Shyh-jier Wang, Hsinchu County, TW;
Hsing-Cheng Yu, Hsinchu County, TW;
Hsing-Yu Lin, Taichung County, TW;
Shir-Kuan Lin, Hsinchu, TW;
Shyh-Jier Wang, Hsinchu County, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
A sensorless driving method for a brushless DC motor is provided. The time for the motor to rotate an electrical angle 60° is obtained by alternatively counting the occurrences of zero crossings with two counters and comparing the counted values, and the motor is delayed an electrical angle of 30°, by which a precise commutating time is obtained. The driving method provides a mask-based phase shift digital detection mechanism for effectively detecting true zero-crossing points. The driving method further provides an inhabitation mechanism with the function of soft-switch for inhibiting noise caused by transistor switching. By using these two counters, the time for the motor to rotate two electrical angles 30°−Δθ and 30°+Δθ are obtained and stored in two registers. The time period before and after the commutating point is added into a pulse width modulation (PWM) signal to reduce the noise and vibration.