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:
Jul. 28, 2009
Filed:
Feb. 07, 2007
Chia-feng Wu, Taoyuan County, TW;
Ching-sen Hsieh, Taoyuan County, TW;
Yueh-lung Huang, Taoyuan County, TW;
Ming-shi Tsai, Taoyuan County, TW;
Chia-feng Wu, Taoyuan County, TW;
Ching-sen Hsieh, Taoyuan County, TW;
Yueh-lung Huang, Taoyuan County, TW;
Ming-shi Tsai, Taoyuan County, TW;
Delta Electronics, Inc., Taoyuan County, TW;
Abstract
A motor control circuit includes a pulse width modulation (PWM) signal generating circuit, a driving circuit and a waveform-shaping circuit connected between the PWM signal generating circuit and the driving circuit. The PWM signal generating circuit generates a square wave with a sequence of alternating on-time and off-time. The waveform-shaping circuit adjusts the rise-time and the fall-time of the square wave to be both within a range of 5% to 15% of the square wave period, and the driving circuit outputs a driving signal to a fan motor according to the adjusted square wave.