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:
Dec. 27, 2005
Filed:
Jun. 29, 2004
Taishi Iwanaga, Nagaokakyo, JP;
Yasunori Yamamoto, Hirakata, JP;
Hideki Nishino, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A PWM control section () gently changes phase currents (Iu, Iv, and Iw) under a current driving control over a pre-drive circuit () and an output circuit (). The pre-drive circuit () suspends energizing of the specific motor coil (Mu, Mv, and Mw) according to a PWM disable signal (NPWM) at PWM disable periods. A self-commutation circuit () performs zero crossing detection according to a BEMF detection signal (DZC) during BEMF detection periods. A count section () selects either a self-commutation signal (SC) or a forced commutation signal (FC) as a commutation signal (CS), whichever enters earlier, and, based on its intervals, generates the PWM disable signal (NPWM) and the BEMF detection signal (DZC). The BEMF detection period starts after the start of the PWM disable period, and finishes together with the PWM disable period at the switching of the energization phases.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile