Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.

Abstract: A dc motor drive system with a PWM control system permits a high-accuracy rotation drive control while detecting the currents flowing into the coils without using shunt resistors. The system drives output MOS transistors by the PWM control to make the currents flow into the coils, and drives to rotate the dc motor. The system includes current sensing MOS transistors having a predetermined size ratio 1/m (M>1) to the output MOS transistors that make the currents flow into the coils. The current sensing MOS transistors are capable of making flow reduced currents proportional to the currents of the output MOS transistors.

Abstract: In start-up control of a motor in which currents are caused to flow through any two of three phase coils to detect the polarity of a voltage induced in each de-energized phase, thereby determining the corresponding energized phase at start-up thereof, based on the polarity of the detected induced voltage, the levels of induced voltages are detected in addition to the polarity of the induced voltage for the de-energized phase to thereby determine the relationship between the magnitudes thereof, and the energized phase at the start-up is determined based on the relationship of magnitude between the polarity of each induced voltage and the level thereof.

Abstract: There is provided a drive control system for sensor-less motor wherein a multi-phase sensor-less motor is driven to rotate by switching a current to be applied to a field coil of each phase depending on the rotating phase of motor and such rotating drive is controlled with the PLL control method and the sensor-less motor is driven with higher reliability. When the motor is to be driven, a desired phase is selected as the detection phase and a voltage (Eu, Ev, Ew) induced on the coil of the detection phase is detected when the power is fed for a short period of time to the field coils except for that of the detection phase. A magnetic pole position of a rotor is detected from the amplitude condition of the detected induced voltage and the power feeding phase of the motor drive is determined based on the result of detection of the magnetic pole position.

Abstract: A drive control system, with PLL control, drives a rotatable multi-phase sensor-less motor by switching a current of a field coil of each phase depending on the rotating phase of the motor. When the moto is driven, a desired phase is selected as a datection phase, and a voltage induced on the coil of the detection phase is detected when power is fed for a predetermined time to the field coils other than the detection phase. A magnetic pole position is detected from the amplitude condition of the detected induced voltage. Based on this detection, the power-feeding phase of the motor drive is determined. Power feeding and pole position detection are performed alternately.

Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.

Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.

Abstract: A dc motor drive system with a PWM control system permits a high-accuracy rotation drive control while detecting the currents flowing into the coils without using shunt resistors. The system drives output MOS transistors by the PWM control to make the currents flow into the coils, and drives to rotate the dc motor. The system includes current sensing MOS transistors having a predetermined size ratio 1/m (M>1) to the output MOS transistors that make the currents flow into the coils. The current sensing MOS transistors are capable of making flow reduced currents proportional to the currents of the output MOS transistors.

Abstract: A drive control system, with PLL control, drives a rotatable multi-phase sensor-less motor by switching a current of a field coil of each phase depending on the rotating phase of the motor. When the motor is driven, a desired phase is selected as a detection phase, and a voltage induced on the coil of the detection phase is detected when power is fed for a predetermined time to the field coils other than the detection phase. A magnetic pole position is detected from the amplitude condition of the detected induced voltage. Based on this detection, the power-feeding phase of the motor drive is determined. Power feeding and pole position detection are performed alternately.

Abstract: In start-up control of a motor in which currents are caused to flow through any two of three phase coils to detect the polarity of a voltage induced in each de-energized phase, thereby determining the corresponding energized phase at start-up thereof, based on the polarity of the detected induced voltage, the levels of induced voltages are detected in addition to the polarity of the induced voltage for the de-energized phase to thereby determine the relationship between the magnitudes thereof, and the energized phase at the start-up is determined based on the relationship of magnitude between the polarity of each induced voltage and the level thereof.

Abstract: There is provided a drive control system for sensor-less motor wherein a multi-phase sensor-less motor is driven to rotate by switching a current to be applied to a field coil of each phase depending on the rotating phase of motor and such rotating drive is controlled with the PLL control method and the sensor-less motor is driven with higher reliability. When the motor is to be driven, a desired phase is selected as the detection phase and a voltage (Eu, Ev, Ew) induced on the coil of the detection phase is detected when the power is fed for a short period of time to the field coils except for that of the detection phase. A magnetic pole position of a rotor is detected from the amplitude condition of the detected induced voltage and the power feeding phase of the motor drive is determined based on the result of detection of the magnetic pole position.

Abstract: There is provided a drive control system for sensor-less motor wherein a multi-phase sensor-less motor is driven to rotate by switching a current to be applied to a field coil of each phase depending on the rotating phase of motor and such rotating drive is controlled with the PLL control method and the sensor-less motor is driven with higher reliability. When the motor is to be driven, a desired phase is selected as the detection phase and a voltage (Eu, Ev, Ew) induced on the coil of the detection phase is detected when the power is fed for a short period of time to the field coils except for that of the detection phase. A magnetic pole position of a rotor is detected from the amplitude condition of the detected induced voltage and the power feeding phase of the motor drive is determined based on the result of detection of the magnetic pole position.

Abstract: A pulse current having such a short duration as the rotor does not react is passed through field coils of respective phases of a brushless motor in first and second, mutually opposite, directions sequentially, voltages induced, by the pulse currents in two directions at each of the field coils of the non-conducting phase are combined, the polarity of a combined voltage is detected, and a field coil pair where a current is to be passed to start the motor is determined based on the result of detection for each of field coil of the non-conducting phase.

Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.

Abstract: A pulse current having such a short duration as the rotor does not react is passed through field coils of respective phases of a brushless motor in first and second, mutually opposite, directions sequentially, voltages induced, by the pulse currents in two directions at each of the field coils of the non-conducting phase are combined, the polarity of a combined voltage is detected, and a field coil pair where a current is to be passed to start the motor is determined based on the result of detection for each of field coil of the non-conducting phase.

Abstract: A pulse current having such a short duration as the rotor does not react is passed through field coils of respective phases of a brushless motor in first and second, mutually opposite, directions sequentially, voltages induced, by the pulse currents in two directions at each of the field coils of the non-conducting phase are combined, the polarity of a combined voltage is detected, and a field coil pair where a current is to be passed to start the motor is determined based on the result of detection for each of field coil of the non-conducting phase.

Abstract: A pulse current having such a short duration as the rotor does not react is passed through field coils of respective phases of a brushless motor in first and second, mutually opposite, directions sequentially, voltages induced, by the pulse currents in two directions at each of the field coils of the non-conducting phase are combined, the polarity of a combined voltage is detected, and a field coil pair where a current is to be passed to start the motor is determined based on the result of detection for each of field coil of the non-conducting phase.

Abstract: A pulse current having such a short duration as the rotor does not react is passed through field coils of respective phases of a brushless motor in first and second, mutually opposite, directions sequentially, voltages induced, by the pulse currents in two directions at each of the field coils of the non-conducting phase are combined, the polarity of a combined voltage is detected, and a field coil pair where a current is to be passed to start the motor is determined based on the result of detection for each of field coil of the non-conducting phase.

Abstract: A pulse current having such a short duration as the rotor does not react is passed through field coils of respective phases of a brushless motor in first and second, mutually opposite, directions sequentially, voltages induced, by the pulse currents in two directions at each of the field coils of the non-conducting phase are combined, the polarity of a combined voltage is detected, and a field coil pair where a current is to be passed to start the motor is determined based on the result of detection for each of field coil of the non-conducting phase.