Minebea Mitsumi Inc.

Minebea Company, Limited

Kazuo Takada

Takayuki Matsui

Haruka Miyaji

Shigeki Miyaji

Hidetoshi Hijikata

Kei Yamazaki

Ayaka Shimada

Scott Jacobs

Hideo Sano

Yasuyuki Hasegawa

Koichi Takeda

Yoshiaki Motoyama

Takayui Matsui

To provide a motor inhibiting emission of electromagnetic noise (EMC) to the outside and a rotary apparatus including the motor. The rotary apparatus of the present disclosure includes: a housing; a motor arranged inside the housing; a circuit board arranged inside the housing and electrically connected to the motor; and a flexible wiring board electrically connecting the motor to the circuit board, the motor including a frame formed with a conductive member, the frame electrically connected via the flexible wiring board to a ground of the circuit board.

Motor and rotary apparatus including the same

A control devicefor a rotary apparatusincludes a driving circuitconfigured to apply a driving voltage to a stepping motorthat rotates an output gear, and a control circuitconfigured to output, to the driving circuit, driving pulses in a number corresponding to a driving target included in a driving command signal from the outside. The control circuitincludes a driving-pulse output unitconfigured to output the driving pulse in the number corresponding to the driving target, a position-information acquiring unitconfigured to acquire position information from a potentiometerthat reads a rotating position of the output gearof the rotary apparatus, and a rotation-abnormality determining unitconfigured to determine, based on the position information acquired by the position-information acquiring unit, whether a rotation abnormality has occurred in the rotary apparatus

Control device for rotary apparatus, rotary apparatus, and control method for rotary apparatus

To provide a motor inhibiting emission of electromagnetic noise (EMC) to the outside and a rotary apparatus including the motor. The rotary apparatus () of the present disclosure includes: a housing (); a motor () arranged inside the housing (); a circuit board () arranged inside the housing () and electrically connected to the motor (); and a flexible wiring board () electrically connecting the motor () to the circuit board (), the motor () including a frame () formed with a conductive member, the frame () electrically connected via the flexible wiring board () to a ground of the circuit board ().

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 control circuit includes an input voltage measuring unit, a temperature measuring unit, a speed setting unit, and a speed control unit. The input voltage measuring unit measures an input voltage input to a motor control device. The temperature measuring unit measures the temperature. The speed setting unit sets a target value of driving speed of a stepping motor based on a measurement result of the input voltage measuring unit, a measurement result of the temperature measuring unit and based on a set value of driving speed preset for each of the plural partial areas which are sectioned in a matrix form with a threshold value related to the input voltage and a threshold value related to the temperature. The speed control unit controls the driving speed according to the target value of the driving speed set in the speed setting unit.

Motor control circuit, motor control device, actuator and control method for stepping motor

A motor control circuit includes an input voltage measuring unit, a temperature measuring unit, a current setting unit, and a current control unit. The input voltage measuring unit measures an input voltage input to the motor control device. The temperature measuring unit measures the temperature. The current setting unit sets a target value of drive current to flow through a coil of a stepping motor based on a measurement result of the input voltage measuring unit and a measurement result of the temperature measuring unit and based on a set value of drive current preset for each of plural partial areas, which are sectioned in a matrix form with a threshold value related to the input voltage and a threshold value related to the temperature. The current control unit controls the drive current according to the target value of the drive current set in the current setting unit.

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.

Motor control device and step-out state detection 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.

A control device for a stepping motor gradually increases an absolute value of the excitation current in phase A from when the start until the end of the hold period such that the amount of change in the excitation current per unit time is smaller than or equal to a first predetermined value. From the start of the hold period until a predetermined time elapses, an absolute value of the excitation current in phase B gradually increases such that the amount of change in the excitation current per unit time is smaller than or equal to the first predetermined value. By the end of the hold period after the predetermined time has elapsed, the excitation current in phase B reaches zero. When the hold period ends, one-phase excitation operation starts and the excitation current flows in phase A first with the same polarity as at the end of the hold period.

In accordance with one aspect of the present disclosure, a motor drive control device is a motor drive control device performing PWM (Pulse Width Modulation) control of a motor, wherein harmonics of a fundamental frequency for PWM control of the motor are included in noise occurring from the motor; the fundamental frequency for PWM control is larger than a frequency corresponding to a bandwidth of a predetermined radio frequency band a communication apparatus uses; and frequencies of continuous harmonic components of the fundamental frequency for PWM control appear before and after the predetermined radio frequency band.

Motor drive control device and method for determining controlled frequency for motor

An address control circuit includes a setting terminal connectable to a ground potential, a time constant setting circuit connected to the setting terminal, and a control unit connected to the time constant setting circuit and configured to set an address for serial communication. The time constant setting circuit includes a resistive element disposed between the setting terminal and the control unit and configured to protect the control unit against overvoltage. The control unit outputs a voltage to the time constant setting circuit, and sets an address at a predetermined timing based on the voltage input from the time constant setting circuit when a predetermined time has passed after the output of the voltage is stopped.

Address control circuit capable of setting address rapidly and method of setting address after power-on reset, the address control circuit providing protection against over-voltage

There is provided a motor control device for controlling a stepping motor having at least two coils. The motor control device includes a controller applies a pulse voltage being subjected to pulse width modulation to each of the coils and provides a stop period to a target coil being subjected to switching of a direction of the coil current, during which the application of the pulse voltage to the target coil is temporarily stopped. The controller also performs a control to set on-duty of the pulse voltage applied to all of the coils except the target coil to be either 100% or 0% during the stop period. An out-of step of the stepping motor is detected when a back electromotive voltage induced in the target coil during the stop period satisfies a predetermined out-of-step determination criterion.

Motor control device and method for detecting out-of-step

There is provided a motor control device controlling an energizing state of a coil of each phase for driving a stepping motor having multiple phase coils. The motor control device includes a detecting unit configured to detect whether the stepping motor is out of step, and a reverse rotating unit configured, when the detecting unit detects that the stepping motor is out of step, to rotate the stepping motor in a second rotation direction reverse to a first rotation direction, which is a rotation direction of the stepping motor before detecting out-of-step, by a number of steps with which a stress received by the stepping motor is alleviated, before the stepping motor spontaneously rotates in the second direction.

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Kosai, Japan

Kazuo Takada