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. 25, 1999
Filed:
Feb. 03, 1998
Hiroshi Ohsawa, Konan, JP;
Shinichi Ohi, Konan, JP;
Kzuyoshi Horiuchi, Konan, JP;
Kouji Ando, Konan, JP;
Zexel Corporation, Tokyo, JP;
Abstract
An object of preventing a reduction in the output efficiency of a motor in the high speed rotation range and reducing the noise of the motor in the low speed rotation range is to be achieved. Since, if a signal that corresponds to the rotation rate has a value equal to or smaller than a specific value, the timing with which a switch performs switching is retarded relative to the timing used when the signal corresponding to the rotation rate has a value larger than the specific value, once the operation shifts to the low speed rotation range, the switching timing is retarded to shift from the setting that gives priority to efficiency, to the setting for achieving noise reduction as long as the switching timing is set in advance so that an optimal output efficiency is achieved in the high speed rotation range.