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:
May. 16, 2000
Filed:
Aug. 06, 1998
Applicant:
Inventors:
Makoto Yoshida, Kusatsu, JP;
Naomi Goto, Otsu, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318254 ; 318439 ;
Abstract
An apparatus for controlling a DC brush-less motor includes a switching circuit which switches a DC voltage to convert the DC voltage into first pulses and a controller which controls the switching circuit. The controller has a voltage detector which detects a voltage of second pulses induced in the windings, a duty ratio control which controls a duty ratio of the first pulse depending upon the induced voltage detected by the voltage detector, and a carrier cycle control which controls a cycle of the first pulse depending upon the duty ratio or a width of the second pulse.