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:
Apr. 07, 2020
Filed:
Feb. 21, 2019
Minebea Mitsumi Inc., Nagano, JP;
MINEBEA MITSUMI INC., Nagano, JP;
Abstract
In order to prevent erroneous detection of motor step-out even when the rotational speed of the motor crosses a resonance region of the motor under acceleration and/or deceleration, a motor control device () includes a control unit for performing control so as to apply a pulse voltage modulated in pulse width to each of coils of plural phases equipped in a motor () and periodically switch the phases of the coil currents flowing through the coils of the plural phases, a back electromotive force measuring unit () for providing a stop period for temporarily stopping application of the pulse voltage to a coil of any one phase out of the coils of the plural phases when the direction of a coil current flowing through the coil of the phase switches, and measuring back electromotive force induced in the coil during the stop period, and a step-out state detecting unit for detecting a step-out state when the rotational speed of the motor () is not in a resonance region of the motor () and the back electromotive force measured by the back electromotive force measuring unit () satisfies a predetermined step-out state determination criterion.