Abstract: An apparatus for driving a motor of a dishwasher includes an AC power source, a rectification circuit for converting an AC power from the AC power source to a DC power, an inverter circuit for converting the DC power from the rectification circuit to an AC power, a motor driven by the inverter circuit to drive a wash pump and/or a drain pump, a current detector for detecting an output current of the inverter circuit, and a controller for performing a PWM (pulse width modulation) control of the inverter circuit based on an output signal of the current detector to thereby control the motor to rotate at a set rotation speed. A phase difference between an output voltage and the output current of the inverter circuit or a reactive current is controlled to have a predetermined value.

Abstract: An apparatus for driving a motor of a dishwasher includes an AC power source, a rectification circuit for converting an AC power from the AC power source to a DC power, an inverter circuit for converting the DC power from the rectification circuit to an AC power, a motor driven by the inverter circuit to drive a wash pump and/or a drain pump, a current detector for detecting an output current of the inverter circuit, and a controller for performing a PWM (pulse width modulation) control of the inverter circuit based on an output signal of the current detector to thereby control the motor to rotate at a set rotation speed. A phase difference between an output voltage and the output current of the inverter circuit or a reactive current is controlled to have a predetermined value.

Abstract: The present invention provides a motor controller capable of driving a synchronous motor having no position sensor stably at high efficiency by carrying out simple control. In order to attain this purpose, a reactive current is obtained from a motor current and a rotation phase, an error voltage is obtained from the reactive current and the command value of the reactive current, thereby obtaining a motor applied voltage command value Va that is used to compensate for the V/f characteristic of the motor. Furthermore, the motor applied voltage command value Va is applied to an output command computing section, and computed with the rotation phase signal of a wave generation section, thereby obtaining a signal for PWM driving the switching devices of an inverter circuit.

Abstract: A linear compressor driving apparatus having an inverter which supplies a driving current of a predetermined frequency to a linear compressor. The linear compressor driving apparatus further includes an inverter controller for controlling the inverter on the basis of resonance frequency information so that the frequency of an output current from the inverter becomes equal to the resonance frequency, and instantaneous values of an output current and an output voltage from the inverter are measured at a phase timing in which an amount of change in the output current of the inverter becomes zero. A piston stroke is calculated from these measured values. In such a linear compressor driving apparatus, a stroke and a top clearance of the piston of the linear compressor can be accurately detected by relatively simple arithmetic processing without using a position sensor.

Abstract: A linear compressor driving apparatus (101) according to the present invention is a linear compressor driving apparatus having an inverter (2) which supplies a driving current of a predetermined frequency to a linear compressor (100), and the apparatus further includes an inverter controller (6) for controlling the inverter (2) on the basis of resonance frequency information so that the frequency of an output current from the inverter becomes equal to the resonance frequency, and instantaneous values of an output current Id and an output voltage Vd from the inverter (2) are measured at a phase timing in which an amount of change in the output current Id of the inverter (2) becomes zero, and a piston stroke is calculated from these measured values. In such linear compressor driving apparatus (101), a stroke and a top clearance of the piston of the linear compressor can be accurately detected by relatively simple arithmetic processing, without using a position sensor.

Abstract: Activated carbon for use in an electric double layer capacitor which has at least activated carbon, electrolyte solution and a separator, the activated carbon having properties of: the total specific surface area of 1000 m2/g or larger; the pore volume distribution of 400 &mgr;l/g or larger for the pores larger than 12 Å and smaller than 40 Å in diameter and of 50 &mgr;l/g or larger for the pores larger than 40 Å in diameter; and the total pore volume of 1000 &mgr;l/g or smaller.

Abstract: A linear compressor driving device for linear compressor driving a piston in a cylinder by means of a linear motor to generate a compressed gas, has an inverter for outputting an alternating current to be supplied to the linear motor; current detecting means for detecting an output current from the inverter; voltage detecting means for detecting an output voltage from the inverter; current amplitude value determining means for determining a current amplitude value of the output current; output power calculating means for calculating an output power from the inverter based on the detected output current and the detected output voltage; frequency determining means for determining a frequency of the output current such that the output power is maximum; and inverter controller for controlling the inverter based on the determined current amplitude value and the determined frequency.

Abstract: The present invention provides a motor controller capable of driving a synchronous motor having no position sensor stably at high efficiency by carrying out simple control. In order to attain this purpose, a reactive current is obtained from a motor current and a rotation phase, an error voltage is obtained from the reactive current and the command value of the reactive current, thereby obtaining a motor applied voltage command value Va that is used to compensate for the V/f characteristic of the motor. Furthermore, the motor applied voltage command value Va is applied to an output command computing section, and computed with the rotation phase signal of a wave generation section, thereby obtaining a signal for PWM driving the switching devices of an inverter circuit.

Abstract: A converter circuit has a reactor connectable to an AC power supply. It further has a PWM converter circuit connected to the reactor, the PWM converter circuit including a high speed diode, a rectifier diode and a switching element connected in parallel to the rectifier diode. The converter circuit further has an input current detector for detecting an input current of the PWM converter circuit, a DC voltage level detector for detecting an output voltage of the PWM converter circuit, a voltage polarity detector connected to the AC power supply, and a control device. The control device measures a variation period of the output voltage measured by the voltage level detector to judge a power supply frequency. It then controls the PWM converter circuit based on a power supply frequency judgement result, a detection result from the voltage level detector, an input current detected by the input current detector, and an output voltage detected by the DC voltage detector.

Abstract: A linear compressor driving device for linear compressor driving a piston in a cylinder by means of a linear motor to generate a compressed gas, has

Abstract: In a brushless motor driving circuit of the invention, in the starting operation, an applying voltage is low and also the induced voltage is low, so that output values from sample and hold circuits 6 and 7 are substantially equal to each other. Thus, an output from a comparing circuit 10 is substantially equal to an output of a V/f converting circuit 11. As a result, the starting method which is identical with a conventional method is used. By contrast, when the number of rotation of a brushless motor 1 is increased, and the induced voltage is started to be observed, the condition is spontaneously shifted to that in which the driving voltage is automatically controlled at each time to an appropriate value for the number of rotation and the load of the motor. Accordingly, the switching operation from the starting control to the normal control is not required.

Abstract: An inverter control apparatus for controlling a command frequency and a command voltage which are supplied to an inverter which then supplies AC power of a desired frequency, accordingly, to an induction motor. The inverter control apparatus receives a requested rotational speed of the motor and an actual rotational speed of the motor is obtained by detecting a frequency of a fluctuation component of a drive current supplied from the inverter to the induction motor. The difference between the requested rotational speed and the actual rotational speed represents a slip amount, which is added to the requested rotational speed to produce a command frequency. The command voltage is set to a voltage acquired when the monitored drive current is at a minimum value.