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:
Nov. 04, 2014
Filed:
Mar. 22, 2012
Toshikazu Satake, Kyoto, JP;
Hiroyuki Ishii, Kyoto, JP;
Toshikazu Satake, Kyoto, JP;
Hiroyuki Ishii, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
A driving device capable of driving a motor more efficiently is provided. A zero-crossing detection comparatorcompares a pair of Hall signals H+ and H− having reverse phases and representing a rotor position of a fan motor, and generates a level-shifted zero-crossing detection signal Sat each zero-crossing timing when the Hall signals cross each other. A control circuitreceives the zero-crossing detection signal S, switches a driving phase at each zero-crossing timing to rotationally drive the motor, and regeneratively controls the motor during a duration from a first time point ahead of each zero-crossing timing by a first time width τto a second time point behind each zero-crossing timing by a second time width τshorter than the first time width τ