A wristwatch includes a first motor that drives a first hour hand, a first control circuit electrically coupled to the first motor and outputting a first motor drive signal, and a second control circuit electrically coupled to the first motor and outputting a second motor drive signal. When the first control circuit outputs the first motor drive signal, the second control circuit is in a high impedance state to the input of the first motor drive signal, and when the second control circuit outputs the second motor drive signal, the first control circuit is in the high impedance state to the input of the second motor drive signal.

An electronic watch includes hands, a stepping motor, a drive circuit, a controller, a current detection circuit that detects a current value flowing through the drive circuit, and a storage unit that stores polarity information of a drive pulse output from the controller to the drive circuit, wherein the controller initializes the polarity information stored in the storage unit when the storage unit is initialized, outputs a polarity detection pulse, which does not cause the stepping motor to rotate by one step, to the drive circuit based on the initialized polarity information, performs a polarity determination processing of determining whether a polarity of the stepping motor and the polarity information match based on the current value detected by the current detection circuit in response to the output of the polarity detection pulse, and changes the polarity information when the polarity of the stepping motor and the polarity information do not match.

An electronic watch includes hands, a stepping motor, a drive circuit, a controller, a current detection circuit that detects a current value flowing through the drive circuit, and a storage unit that stores polarity information of a drive pulse output from the controller to the drive circuit, wherein the controller initializes the polarity information stored in the storage unit when the storage unit is initialized, outputs a polarity detection pulse, which does not cause the stepping motor to rotate by one step, to the drive circuit based on the initialized polarity information, performs a polarity determination processing of determining whether a polarity of the stepping motor and the polarity information match based on the current value detected by the current detection circuit in response to the output of the polarity detection pulse, and changes the polarity information when the polarity of the stepping motor and the polarity information do not match.

The present disclosure provides a motor drive device. The motor drive device includes a current detection unit, a control unit and a determination unit. The current detection unit detects a current flowing through a motor coil. The control unit executes a slow attenuation mode that attenuates the current after an end of a power supply mode. The determination unit determines whether the current at a second time point while a predetermined time has elapsed from a first time point when the power supply mode is switched to a slow decay mode is below a limit value. When the determination unit determines that the current does not fall below the limit value, the control unit is configured to switch from the slow attenuation mode to a fast attenuation mode at the second time point.

A method for controlling a stepper motor includes calculating a duty cycle of a current provided to the stepper motor and comparing a difference, between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value. The method also includes adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.

A method for controlling a stepper motor includes calculating a duty cycle of a current provided to the stepper motor and comparing a difference, between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value. The method also includes adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.

A driver device includes a control circuit for controlling an output stage circuit for supplying an output current to a coil, and makes a movable part move with the magnetism generated by the supplied output current. The control circuit can perform holding control to hold the state of the movable part unchanged by suspending its movement. During the holding control by the control circuit, application of an external force tending to change the state of the movable part against the holding control is detected based on the state of supply of electric power to the coil by the output stage circuit, the output current, or the current flowing through the output stage circuit.

A driver device includes a control circuit for controlling an output stage circuit for supplying an output current to a coil, and makes a movable part move with the magnetism generated by the supplied output current. The control circuit can perform holding control to hold the state of the movable part unchanged by suspending its movement. During the holding control by the control circuit, application of an external force tending to change the state of the movable part against the holding control is detected based on the state of supply of electric power to the coil by the output stage circuit, the output current, or the current flowing through the output stage circuit.

A stepping motor control device is provided, which controls a stepping motor including a rotor position detector by micro-step driving. The control device has a plurality of operation modes including an adjustment mode and a use mode. In the adjustment mode, the control device generates control data for a closed loop control for controlling the winding current of the stepping motor based on the detection value of the rotor position detector, and performs a stepping motor acceleration operation and a stepping motor deceleration operation according to the control data. In the use mode, the control device performs the stepping motor acceleration operation and the stepping motor deceleration operation so that a winding current observed in the adjustment mode is reproduced by an open loop control for controlling the winding current of the stepping motor based on the control data generated in the adjustment mode.

A stepping motor control device is provided, which controls a stepping motor including a rotor position detector by micro-step driving. The control device has a plurality of operation modes including an adjustment mode and a use mode. In the adjustment mode, the control device generates control data for a closed loop control for controlling the winding current of the stepping motor based on the detection value of the rotor position detector, and performs a stepping motor acceleration operation and a stepping motor deceleration operation according to the control data. In the use mode, the control device performs the stepping motor acceleration operation and the stepping motor deceleration operation so that a winding current observed in the adjustment mode is reproduced by an open loop control for controlling the winding current of the stepping motor based on the control data generated in the adjustment mode.