Abstract: A semiconductor device for controlling a three-phase motor with double windings, includes a first inverter that drives a first winding of the three-phase motor, a second inverter that drives a second winding of the three-phase motor and a communication line between the first and second inverters. The first and second inverters, through the communication line, notify a respective operation state each other.

Abstract: A drive apparatus for a motor having a stator and a rotor, the drive apparatus including a current detection unit configured to detect, when the motor is rotating, each of multi-phase currents flowing through coils of the stator, and a control unit for controlling the motor by sensor-less control configured to convert the detected multi-phase currents into a d-axis current Id and a q-axis current Iq in a d-q coordinate system, calculate a phase error between an actual rotational position of the rotor and an imaginary rotational position thereof by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, perform control so that the phase error gets closer to zero, and output voltage command values to a motor drive circuit.

Abstract: A semiconductor device for controlling a three-phase motor with double windings, includes a first inverter that drives a first winding of the three-phase motor, a second inverter that drives a second winding of the three-phase motor and a communication line between the first and second inverters. The first and second inverters, through the communication line, notify a respective operation state each other.

Abstract: A drive apparatus for a motor having a stator and a rotor, the drive apparatus including a current detection unit configured to detect, when the motor is rotating, each of multi-phase currents flowing through coils of the stator, and a control unit for controlling the motor by sensor-less control configured to convert the detected multi-phase currents into a d-axis current Id and a q-axis current Iq in a d-q coordinate system, calculate a phase error between an actual rotational position of the rotor and an imaginary rotational position thereof by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, perform control so that the phase error gets closer to zero, and output voltage command values to a motor drive circuit.

Abstract: An oil-pump motor drive apparatus includes a current detection unit for detecting each of multi-phase currents flowing through coils of a stator, a control unit for converting the detected multi-phase currents into a d-axis current Id and a q-axis current Iq, calculating a phase error between an actual rotational position of the rotor and an imaginary rotational position by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, performing control so that the phase error gets closer to zero, and outputting voltage command values indicating voltages to be applied to respective phases of the brushless motor, to a motor drive circuit, in which the control unit sets the d-axis current command value Idref to a value larger than zero when the number of revolutions of the motor is smaller than a predetermined number.

Abstract: An oil-pump motor drive apparatus includes a current detection unit for detecting each of multi-phase currents flowing through coils of a stator, a control unit for converting the detected multi-phase currents into a d-axis current Id and a q-axis current Iq, calculating a phase error between an actual rotational position of the rotor and an imaginary rotational position by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, performing control so that the phase error gets closer to zero, and outputting voltage command values indicating voltages to be applied to respective phases of the brushless motor, to a motor drive circuit, in which the control unit sets the d-axis current command value Idref to a value larger than zero when the number of revolutions of the motor is smaller than a predetermined number.

Abstract: A communication system is provided in electric devices such as refrigerators. Refrigerators include a plurality of output units such as electric fans, electric dampers, and output units such as sensors, thermistors, etc. The communication system is provided in the vicinity of the input and output units. The communication system includes a plurality of sub-control sections for controlling operations of the output units, a main control section for controlling the electric device by controlling operations of each sub-control section, a single communication-use cable for connecting the main control section and the sub-control sections so as to permit communications between them. The communication system permits a reduction in the number of cables required for connecting the main control section to the input and output units and simplified processes for routing the cables. As a result, compact size electric devices and reduction in manufacturing costs are enabled.

Abstract: A communication system of the present invention is provided in electric devices such as refrigerators including a plurality of output units such as electric fans, electric dampers, and output units such as sensors, thermistors, etc. The communication system is provided in the vicinity of the input and output units. The communication system includes a plurality of sub-control sections for controlling operations of the output units, a main control section for controlling the electric device by controlling operations of each sub-control section, a single communication-use cable for connecting the main control section and the sub-control sections so as to permit communications between them. Bidirectional communications between the main control section and each sub-control section are carried out through the communication-use cable.