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:
Oct. 23, 2012
Filed:
Dec. 01, 2008
Jiro Suzuki, Anjo, JP;
Takuya Kusakawa, Anjo, JP;
Jiro Suzuki, Anjo, JP;
Takuya Kusakawa, Anjo, JP;
Makita Corporation, Anjo-Shi, JP;
Abstract
A motor controller comprises a processor selectively outputting an on-signal to either one of an upper arm switching element and a lower arm switching element based upon a detected position by the position sensor, gate drivers inputting a driving voltage to the gates of the switching elements by shifting a level of the on-signal from the processor to the upper arm switching element and a bootstrap capacitor configured to be charged while the upper arm switching element is turned off and to behave as a voltage supply for the gate driver while the upper arm switching element is turned on. The processor is configured to reduce a set duty ratio when the set duty ratio is equal to or larger than a predetermined value (e.g. 80 percents) and a rotational position of the motor does not change for a first predetermined time. This motor controller can prevent the switching element from a burnout even if the motor is locked.