Minebea Mitsumi Inc.

Ayaka Shimada

Kazuo Takada

Takayuki Matsui

Haruka Miyaji

Kei Yamazaki

Hidetoshi Hijikata

Shigeki Miyaji

Hideo Sano

A control device for a stepping motor capable of hold control that can smoothly reduce an excitation current at a rotation stopping time of the stepping motor is provided. A control device () for a stepping motor () causes an excitation current to flow in a plurality of coils to rotate a rotor. The control device () includes a driving circuit () that applies a driving voltage to the coils, and a control circuit () that controls the driving voltage. The control circuit () performs hold control to move the rotor to a predetermined stop position by changing a magnitude of the excitation current flowing in the coils so that the magnitude of the excitation current becomes close to a target current value that gradually decreases, in a hold time period at a rotation stopping time of the stepping motor (). The control circuit () sets an operation mode of the driving circuit () at an operation mode corresponding to a comparison result of the magnitude of the excitation current and the target current value, of a plurality of operation modes, at each predetermined period in the hold time period. The plurality of operation modes include a charge mode to increase the excitation current and a first attenuation mode to attenuate the excitation current.

Control device for stepping motor and control method for stepping motor

A motor drive control device has a controller and a driver. The controller generates a control signal for controlling driving of a two-phase stepping motor so as to alternately repeat one-phase excitation in which a coil of one phase in coils of two phases of the two-phase stepping motor is excited and two-phase excitation in which the coils of two phases in the coils of the two phases are excited. The driver drives the coils of the two phases, based on the control signal. The controller determines, based on a back electromotive force generated in the coil that was not excited during the one-phase excitation, a period of performing the one-phase excitation, and determines, based on the period of the one-phase excitation performed before the two-phase excitation, a period of performing the two-phase excitation.

Motor drive control device, motor unit, and motor drive control method

A motor controller capable of more reliably starting a stepping motor even if a predetermined drive power is supplied to the stepping motor, and to a control method for the stepping motor is provided. The motor controller driving a stepping motor detects that the stepping motor is in a step-out state after a start operation of the stepping motor is performed. If predetermined determination conditions are satisfied, when it is detected that the stepping motor is in a step-out state, it is determined that a restart operation of the stepping motor is performed, and the stepping motor is restarted.

Motor controller and control method for stepping motor

A motor control circuit () capable of performing a high-precision step-out determination under a wide range of conditions. The motor control circuit () includes an input voltage measuring unit (), a temperature measuring unit (), a back electromotive force measuring unit (), a determination threshold value setting unit, and a determination unit. The input voltage measuring unit () measures an input voltage input to a motor control device (). The temperature measuring unit () measures temperature. The back electromotive force measuring unit () measures back electromotive force induced in a coil for which energization is stopped out of the coils of plural phases. The determination threshold value setting unit sets a determination threshold value of back electromotive force based on a measurement result of the input voltage measuring unit () and a measurement result of the temperature measuring unit (), and based on a determination reference value that is preset for each of plural partial areas sectioned in a matrix form with a threshold value relating to the input voltage and a threshold value relating to the temperature. The determination unit makes a determination on step-out of a stepping motor () based on a measurement result of the back electromotive force measuring unit () and the set determination threshold value of the back electromotive force.

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Fukuroi, Japan

Ayaka Shimada