Abstract: An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.

Abstract: When a driver unit is in a high impedance state as viewed from a first coil or a second coil, an induced voltage detector detects the voltage across the first coil or that across the second coil so as to detect an induced voltage occurring in the first coil or the second coil. The induced voltage detector includes a differential amplifier circuit for differentially amplifying an electric potential across the first coil or that across the second coil, and an analog-to-digital converter circuit for converting an analog value outputted from the differential amplifier circuit into a digital value and outputting the converted digital value to a control unit. The control unit generates a drive signal based on an input signal set externally and adjusts the drive signal in accordance with the induced voltage detected by the induced voltage detector so as to set the adjusted drive signal in the driver unit.

Abstract: An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.

Abstract: An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.

Abstract: A stepping motor includes two coils and has supply currents to the two coils with different phases so that a rotor is rotated by the two coils. During a period where one coil is in a high impedance state, an induced voltage generated at that coil is detected. An output control circuit controls the magnitude of motor drive current supplied to the two coils in accordance with the detected induced voltage state. Then, prior to entering the high impedance state from the drive state, a short-circuit period is provided for short circuiting both terminals of the coil.

Abstract: When a driver unit is in a high impedance state as viewed from a first coil or a second coil, an induced voltage detector detects the voltage across the first coil or that across the second coil so as to detect an induced voltage occurring in the first coil or the second coil. The induced voltage detector includes a differential amplifier circuit for differentially amplifying an electric potential across the first coil or that across the second coil, and an analog-to-digital converter circuit for converting an analog value outputted from the differential amplifier circuit into a digital value and outputting the converted digital value to a control unit. The control unit generates a drive signal based on an input signal set externally and adjusts the drive signal in accordance with the induced voltage detected by the induced voltage detector so as to set the adjusted drive signal in the driver unit.

Abstract: A stepping motor includes two coils and has supply currents to the two coils with different phases so that a rotor is rotated by the two coils. During a period where one coil is in a high impedance state, an induced voltage generated at that coil is detected. An output control circuit controls the magnitude of motor drive current supplied to the two coils in accordance with the detected induced voltage state. Then, prior to entering the high impedance state from the drive state, a short-circuit period is provided for short circuiting both terminals of the coil.

Abstract: An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.