An air conditioner having a permanent magnet electric motor with a high output power characteristic in a cooling and heating range and a high output characteristic even in defrosting operation in a high-speed range.

An apparatus such as an air conditioner, refrigerator or washing machine having a control apparatus for use in a brushless motor facing a part of a compressor and/or blower of the apparatus. The control apparatus includes a voltage detector for generating a detection voltage in response to a terminal voltage of plural phases of a stator winding of the brushless motor, a standard voltage generator for generating a standard voltage, a comparator for outputting a comparison result information signa...

A phase signal generation circuit is constituted by using a comparison circuit 10, a delay circuit 11, a gate signal preparation circuit 13, and a selection holding circuit 12. A phase signal generated in the phase signal generation circuit 9 is pattern recognized in a control circuit 6 and a position of a rotor is detected and a PWM control area, PAM control, and a change-over PWM/PAM is carried out. The rotor position detection accuracy can be heightened and a wide control. range can be obtain...

A switching circuit can reduce switching power loss and can vary at least one of the switching frequency and the conduction rate of switching of the switching circuit with less dependency on a frequency of a resonating circuit. A converter unit employs the switching circuit for expansion of control range of an output voltage. A primary switching element forming the switching circuit is provided with a resonance circuit and an auxiliary switching element. With the auxiliary switching element, res...

A current controller has provided therein assumed response generating means and load model means so as to realize repetitive type control with no influence of control delay against a periodically repetitive current response. This current controller is applied to a 120-degree current flow type motor using a pulse width modulation inverter, so that the DC current control including the process of response to the rise of the current can be realized only by a microcomputer.

A power source apparatus has a power factor improving circuit which uses switching elements (4) as buildup transistors. According to the power source apparatus of the present invention, a current carrying ratio of the switching elements is decided to be a value which is obtained by subtracting a number of proportional value of the power source current waveform from the maximum current carrying ratio. Since the device of the present invention does not necessitate a detecting circuit of the power ...

A method controls a torque of an a. c. motor which does not cause a shortage of torque by using an economical current detection which estimates d- and q-axis currents Idc, Iqc from d. c. current IDC flowing through an input d. c. bus line of a power converter. A value of d- and q-axis motor currents Id, Iq of a rotational coordinate system are estimated from detected input d. c. current IDC flowing through the bus line of the power converter to which power is input from a d. c. power source 21. ...

A circuit for controlling the outdoor unit of an air conditioner comprises a microcomputer which controls two brushless motors and a microcomputer which controls the whole outdoor unit. In accordance with the present invention, separation of a function for controlling the brushless motors from a function for controlling the whole outdoor unit can simplify software for said microcomputers.

A converter module which receives an AC voltage, converts the AC voltage to a DC voltage, and outputs the DC voltage to a circuit for driving a motor. The converter module includes a switching device, a diode, and a control circuit which controls the DC voltage output by the converter module by controlling the switching device. The control circuit includes a plurality of DC voltage detection terminals which detect the DC voltage output by the converter module with respective different DC voltage...

A motor controller is made up of a power supply circuit rectifying an AC power supply for outputting desired DC voltages while, at the same time, improving the power factor of the AC power supply, and a motor drive circuit for driving a motor. The controller has a rectifier circuit for converting AC power to a DC voltage and a smoothing circuit, a converter circuit constituted of a chopper circuit for controlling the DC voltage by utilizing a switching operation and the energy storing effect of ...