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:
Sep. 13, 2011
Filed:
Dec. 12, 2008
Satoshi Narumi, Itami, JP;
Masaaki Kato, Itami, JP;
Masaharu Hoashi, Itami, JP;
Toshiya Suzuki, Itami, JP;
Satoshi Narumi, Itami, JP;
Masaaki Kato, Itami, JP;
Masaharu Hoashi, Itami, JP;
Toshiya Suzuki, Itami, JP;
Renesas Electronics Corporation, Kawasaki-shi, JP;
Abstract
The present invention provides a motor drive apparatus which improves a trade-off relation between a stable position detection and noise at its driving. A sensorless drive operation circuit calculates by operation a zero cross point (point p) of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval. After the point p has been calculated, points a and b are detected by interrupting a predetermined time drive current.