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. 20, 2014
Filed:
Oct. 25, 2011
Toshiya Suzuki, Kyoto, JP;
Shinsuke Sano, Kyoto, JP;
Atsushi Sato, Kyoto, JP;
Eri Kishimoto, Kyoto, JP;
Toshiya Suzuki, Kyoto, JP;
Shinsuke Sano, Kyoto, JP;
Atsushi Sato, Kyoto, JP;
Eri Kishimoto, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
A BEMF detection circuit generates a rotation detection signal indicating a comparison result between electromotive force voltages Vthrough Vwhich occur at a terminal of respective multiple coils and an intermediate-point voltage V. A rotor position detection circuit generates a rotor position detection signal indicating a stopped rotor position An internal start-up synchronization signal generating unit generates a predetermined-frequency forced synchronization signal. Upon receiving a fan motor start-up instruction, a driving signal synthesizing circuit generates a driving control signal based upon the rotor position detection signal. Thus, (1) when back electromotive force voltage occurs, a sensorless driving operation is started based upon the rotation detection signal; (2) when it does not occur, the driving control signal is generated based upon the forced synchronization signal. Subsequently, when it occurs, the sensorless driving operation is started based upon the rotation detection signal.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile