Abstract: A motor control device includes a magnetization control unit energizing a motor winding to change magnetic flux content of permanent magnet motor, a current detector detecting current supplied to the motor, a vector control unit including a speed/position estimation unit carrying out an operation to estimate a motor rotational speed and rotational position, the vector control unit carrying out a vector control of the motor, an induced voltage detector detecting an induced voltage of the motor based on the rotational speed, motor currents obtained by the vector control unit, output voltages of the drive unit, a winding inductance or the motor constant and a winding resistance, an induced voltage command determining unit determining an induced voltage command based on the motor rotational speed and output torque, and a magnetization current determining unit determining an amount of energization based on the induced voltage of the motor and the induced voltage command.

Abstract: An inverter for a washer performing drive control of an electric motor imparting a rotational driving force required for washing, rinsing and dehydrating operations in a full automatic washer performing the washing, rinsing and dehydrating processes continuously. The inverter comprises control means for operating the motor with a full field in the low speed rotational region of washing, rinsing and dehydrating operations, with weak field in the high speed rotational region of dehydrating operation, and performing vector control of the output of the motor in the case of full field operation, and voltage/phase control of the motor in the case of field weakening operation.

Abstract: A motor control unit including a rotational position detector detecting a rotational position of a brushless DC motor; a current detector detecting a current of the brushless DC motor; a coordinate transformer executing rotational coordinate transformation of the current by a control phase angle and obtaining a d-axis current and a q-axis current; a current controller generating a command d-axis voltage based on a d-axis current error, and generating a command q-axis voltage based on a q-axis current error; a coordinate transformer generating a three-phase command voltage by the control phase angle; a conductive signal generator; and a position controller that, when executing a positioning operation, maintains the command d-axis current at a constant value and the command q-axis current at zero, and that controls the control phase angle based on a difference between a target stop rotational position and a rotational position detected by the rotational position detector.

Abstract: A motor controller includes a reference signal generator; an A/D converter performing A/D conversion of the cosine and the sine signals outputted from a resolver; a first amplitude calculator calculating cosine and sine signal amplitudes based on twice-A/D converted cosine and sine signals respectively; a second amplitude calculator calculating averages of the cosine and the sine signals, and that calculates the amplitude of the cosine signal from a difference between the cosine signal average and a latest A/D converted cosine signal, and that calculates the amplitude of the sine signal from a difference between the sine signal average and a latest A/D converted sine signal; a synthesizer synthesizing the cosine and sine signal amplitudes obtained by the first and the second amplitude calculators respectively; a rotational angle calculator calculating a rotational angle based on the synthesized cosine and sine signal amplitudes; and a PWM controller.

Abstract: An X-ray CT device including a stationary part; a rotary part rotatable relative to the stationary part; an X-ray tube provided at the rotary part for radiating X-ray beams on an object; an X-ray detector provided at the rotary part opposing the X-ray tube, and that detects the X-ray beams passed through the object; an image processor that generates cross-sectional images of the object based on a detection signal outputted from the X-ray detector; a display that shows the cross-sectional images based on output signals delivered from the image processor; a first transmitting section configured by a rotary step-up transformer having a primary and secondary windings residing at the stationary and the rotary part respectively, and that steps up AC voltage provided by AC power source, and that further executes non-contact power transmission from the stationary part to the rotary part for supplying power to the X-ray tube.

Abstract: A motor control device is disclosed which is arranged so as to perform a PWM control for a permanent magnet motor including a rotor having a permanent magnet and a stator with a multiphase winding. The motor control device includes a position detection unit which executes an analog computation process for induced voltages of respective phases of the motor based on voltage, current and a constant of the motor and a phase voltage equation, thereby generating and delivering a rotational position signal of the rotor based on a phase relation of the induced voltages, and a digital processing unit which has a function of generating and delivering a PWM signal based on the rotational position signal, thereby controlling the motor.

Abstract: A motor control unit including a rotational position detector detecting a rotational position of a brushless DC motor; a current detector detecting a current of the brushless DC motor; a coordinate transformer executing rotational coordinate transformation of the current by a control phase angle and obtaining a d-axis current and a q-axis current; a current controller generating a command d-axis voltage based on a d-axis current error, and generating a command q-axis voltage based on a q-axis current error; a coordinate transformer generating a three-phase command voltage by the control phase angle; a conductive signal generator; and a position controller that, when executing a positioning operation, maintains the command d-axis current at a constant value and the command q-axis current at zero, and that controls the control phase angle based on a difference between a target stop rotational position and a rotational position detected by the rotational position detector.

Abstract: A motor control device for controlling a permanent magnet motor includes a current detector detecting current flowing through three-phase windings, an induced voltage computing unit obtaining voltage induced at each phase from the detected three-phase winding current based on a phase voltage equation, a position detector detecting a rotational position of the rotor from the induced voltage of each phase computed by the induced current computing unit, the rotational position of the rotor having a 6n resolution where n is an integer equal to or larger than 1, an energization phase control unit determining a phase to be energized based on the rotational position of the rotor and a phase command, an energization signal forming unit forming a 6n-resolution three-phase energization signal, and an energizing unit carrying out PWM modulation for the three-phase energization signal, supplying voltage according to the modulated three-phase energization signal to each of the three-phase windings.

Abstract: A motor control device for controlling a permanent magnet motor includes a current detector detecting current flowing through three-phase windings, an induced voltage computing unit obtaining voltage induced at each phase from the detected three-phase winding current based on a phase voltage equation, a position detector detecting a rotational position of the rotor from the induced voltage of each phase computed by the induced current computing unit, the rotational position of the rotor having a 6n resolution where n is an integer equal to or larger than 1, an energization phase control unit determining a phase to be energized based on the rotational position of the rotor and a phase command, an energization signal forming unit forming a 6n-resolution three-phase energization signal, and an energizing unit carrying out PWM modulation for the three-phase energization signal, supplying voltage according to the modulated three-phase energization signal to each of the three-phase windings.

Abstract: A controller for a motor to be mounted on a vehicle includes a boosting circuit 2 for raising the voltage of a battery that is disposed near the battery 1, a motor driving circuit 4 disposed near the motor 3 to be mounted on the vehicle for controlling the motor 3 to be mounted on the vehicle to be driven in accordance with boosted voltage outputted from the boosting circuit and a communication unit 5 disposed between the boosting circuit 2 and the motor driving circuit 4.

Abstract: A washing machine includes an electric motor developing torque used for wash, rinse and dehydration operations, a current detector detecting current flowing into the motor, and a torque controller performing a vector control for the motor on the basis of the current detected by the current detector so that the torque developed by the motor is optimum for at least each of the wash and dehydration operations.

Abstract: An inverter for a washer performing drive control of an electric motor imparting a rotational driving force required for washing, rinsing and dehydrating operations in a full automatic washer performing the washing, rinsing and dehydrating processes continuously. The inverter comprises a control means for operating the motor with a full field in the low speed rotational region of washing, rinsing and dehydrating operations, with weak field in the high speed rotational region of dehydrating operation, and performing vector control of the output of the motor in the case of full field operation, and voltage/phase control of the motor in the case of field weakening operation.

Abstract: An inverter device includes a DC power supply, an inversion section connected via a DC power supply line to the DC power supply to be supplied with DC voltage from the DC power supply, thereby delivering AC voltage, a current-detecting resistor connected to the DC power supply line and having both ends, and a current detector detecting current on the basis of voltage developed across both ends of the current-detecting resistor. The current detector includes a voltage-dividing resistor, connected between a level-shift power supply line having a predetermined level-shift voltage and one of the ends of the current-detecting resistor, the voltage-dividing resistor having a voltage-dividing point.

Abstract: A washing machine includes an electric motor developing torque used for wash, rinse and dehydration operations, a current detector detecting current flowing into the motor, and a torque controller performing a vector control for the motor on the basis of the current detected by the current detector so that the torque developed by the motor is optimum for at least each of the wash and dehydration operations.

Abstract: An inverter device includes a DC power supply, an inversion section connected via a DC power supply line to the DC power supply to be supplied with DC voltage from the DC power supply, thereby delivering AC voltage, a current-detecting resistor connected to the DC power supply line and having both ends, and a current detector detecting current on the basis of voltage developed across both ends of the current-detecting resistor. The current detector includes a voltage-dividing resistor, connected between a level-shift power supply line having a predetermined level-shift voltage and one of the ends of the current-detecting resistor, the voltage-dividing resistor having a voltage-dividing point.

Abstract: A full-automatic washing machine includes an outer tub, a rotatable tub rotatably mounted in the outer tub, an agitator rotatably mounted in the rotatable tub, and a brushless motor for direct driving at least one of the rotatable tub and the agitator. The brushless motor including windings of a plurality of phases and a rotor. Also, the washing machine includes rotor position detecting elements to detect a rotational position of the rotor. The rotor position detecting element are less in number than the phases of the motor. An energizing signal forming element to generate a sinusoidal energizing signal for each of the phases based on the detected rotational position of the rotor. Last, a driving element to energize the windings of the phases based on the energizing signals.

Abstract: A full automatic washing machine includes an outer tub, a rotatable tub mounted for rotation in the outer tub, an agitator mounted for rotation in the rotatable tub, a brushless motor for directly driving the agitator or the rotatable tub and the agitator, and a Hall IC for detecting a rotational position of a rotor of the brushless motor, generating a position signal. A sinusoidal energization signal is formed on the basis of the position signal generated by the Hall IC. The brushless motor is energized on the basis of the formed energization signal.

Abstract: A washing machine includes a hollow tub shaft mounted on a first stationary portion of the machine for rotation, a rotatable tub rotatably mounted on an upper end of the tub shaft, an agitator shaft concentrically inserted in the tub shaft for rotation, an agitator mounted on the upper end of the agitator shaft, a stator fixed to a second stationary portion of the machine to be concentric with the agitator shaft to constitute an electric motor together with the stator, and a clutch including a holder mounted on the tub shaft for rotation with the tub shaft.

Abstract: An inverter controlling a brushless motor includes a microcomputer detecting a rotational position of a motor rotor on the basis of comparison signals obtained by comparison of terminal voltages of respective windings of the brushless motor with a reference voltage, determining a commutation timing. The current flowing through a DC power line is detected by a shunt resistor and the detected current is sampled and compared sequentially by the microcomputer. The microcomputer obtains a compensation time period in accordance with the result of comparison. The commutation timing of each of switching transistors of the inverter is compensated with respect to a reference commutation timing by the obtained compensation time period. Alternatively, the microcomputer detects energization time periods of diodes as the commutation time periods on the basis of the comparison signals and determine the commutation timing from the detected commutation time periods.

Abstract: An inverter controlling an air conditioner including a brushless motor serving as a compressor motor. A microcomputer detects the rotational position of a rotor of the brushless motor from signals obtained by comparison of each of terminal voltages of the motor windings with a reference voltage in order to determine a commutation time. In a normal operation, the microcomputer forms, according to a normal energization signal forming pattern, energization signals corresponding to every commutation time at every occurrence of the commutation time, so that the motor windings are sequentially energized. When frost forms on an outdoor heat exchanger of a heat pump during a warming operation and a defrosting operation is necessary, the energization signals are formed according to a loss increasing energization signal forming pattern so that loss increasing energization signals for causing the rotor to produce counter torque are added to the respective energization signals formed according to the normal pattern.