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. 26, 2004
Filed:
Sep. 16, 2002
Chia-Chang Hsu, Hsinchu, TW;
Chung-Hsien Lin, Taipei, TW;
Prolific Technology, Inc., Taipei, TW;
Abstract
An apparatus for controlling a rotational speed of a motor, coupled to a sensing unit capable of outputting a sensing signal. The apparatus includes a controlling unit, coupled to the sensing unit, for outputting a controlling signal according to the sensing signal and independently of the rotational speed of the motor. The controlling signal is a square wave and has a duty ratio that is determined by the sensing signal. The apparatus also includes a driving unit, coupled to the controlling unit, for outputting a driving signal to a motor rotor according to the duty ratio of the controlling signal. The driving signal also is a square wave. The rotational speed of the motor rotor is determined by the duty ratio of the driving signal.