Title:
MOTOR
Document Type and Number:
WIPO Patent Application WO/2015/025749
Kind Code:
A1
Abstract:
A brushless DC motor for cutting an object to be cut by rotating a blade has: a shaft for, when the brushless DC motor is driven, rotating the blade; a drive means for driving the brushless DC motor by a PWM control; a rotation detection means for detecting the rotation and outputting a rotation detection signal; and a rotation speed determination means for performing arithmetic processing on the rotation detection signal and determining the rotation speed. The rotation speed determination means comprises: a lower limit rotation speed determination means for determining whether or not the rotation speed becomes lower than a lower limit rotation speed because of a load imposed on the brushless DC motor; and an output means for outputting the result of the rotation speed determination means. While the motor is being driven at a predetermined duty ratio by the drive means, when the rotation speed determination means outputs a signal indicating that the rotation speed becomes lower than the lower limit rotation speed, the drive means sets the duty ratio to a first duty ratio having a value larger than the predetermined duty ratio.
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| JP4019241 | Motor controller and method |
Inventors:
SHIMIZU DAISUKE (JP)
CHIYOMATSU NOBUMITSU (JP)
CHIYOMATSU NOBUMITSU (JP)
Application Number:
PCT/JP2014/071127
Publication Date:
February 26, 2015
Filing Date:
August 09, 2014
Export Citation:
Assignee:
NIDEC CORP (JP)
International Classes:
H02P6/08; B26D3/26
Domestic Patent References:
| WO2012108415A1 | 2012-08-16 |
Foreign References:
| JP2012030323A | 2012-02-16 | |||
| JPS60242815A | 1985-12-02 |
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