Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Tunehiro Endo

Kunio Miyashita

Fumio Tajima

Tsuyoshi Tanaka

Kazuo Tahara

Haruo Koharagi

Yoshitaro Ishii

Junnosuke Nakatsugawa

Fumio Jyoraku

Hisanori Toyoshima

Motoo Futami

Takeshi Abe

Hiroshi Katayama

Toshiyuki Ajima

Shigeru Machida

Takashi Ikimi

Yozo Nakamura

Hiroaki Hata

Nobuyoshi Mutoh

Yasuo Notohara

Keijiro Sakai

Yuzuru Kubota

Akira Arai

Seizi Yamashita

Yukio Kawabata

Syuji Watanabe

Kenji Sakurai

Kenichi Iizuka

Mitsuyuki Honbu

Naoyuki Tanaka

Kouichi Saito

Seiichi Narushima

Hisao Suka

Akihiko Ishiyama

Wakichiro Hishi

Hitoshi Ohura

Yoshio Ishida

Kazuo Ikeda

Yoshihisa Uneyama

Mitsuhisa Kawamata

Jun Ohya

Atusi Hosokawa

Tooru Kitayama

Takeoshi Katoh

Kouchi Saito

Nobuaki Kato

A control apparatus and a semiconductor apparatus of AC motors capable of reducing torque ripple with a comparatively simple circuit corresponding to a high withstand voltage and capable of driving a motor at high efficiency even when the rotational speed or load has changed. The control apparatus detects first phase signals fixed in relative phase to induced voltages of the motor and current polarity signals, recognizes phase differences between them, generates second phase signals so as to make the phase differences approach zero to drive the motor at high efficiency, generates modulation wave signals having quasi-sinusoidal waveforms or trapezoidal waveforms on the basis of the second phase signals, compares the modulation wave signals with a carrier wave signal, and conducts PWM control on an inverter.

Control apparatus, dual chip inverter and single chip inverter of AC motors

The present invention enables modulated wave signals having extremely small waveform distortion to be generated using a relatively simple circuit, and thereby it is possible to hold down vibrations and noise of a motor, which are attributable to torque ripples. In order to remove defects of the conventional techniques, the circuit generates a plurality of trapezoidal wave signals having at least two constant levels based on position sensing signals of magnetic pole of a motor, generates quasi-sinusoidal wave signals at a quasi-sinusoidal wave modulator based on the plurality of trapezoidal wave signals, and compares the quasi-sinusoidal wave signals with a carrier wave so as to perform PWM control of an inverter.

Driving equipment and semiconductor equipment for alternating-current motor

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.

Current controller for controlling a current flowing in a load using a

A controlling apparatus controls a suction performance of a blower motor which is installed into a cleaner main body. The controlling apparatus increases the suction performance when a suction nozzle is operated and decreases the suction performance when the suction nozzle is stopped. Corresponding to a floor use suction nozzle and a crevice use suction nozzle, at a predetermined air flow amount range, the most suitable operation control being suited to a discriminated suction nozzle can carried out automatically. Plural kinds of the suction nozzles at an actual use scope are set beforehand. When the suction nozzle is exchanged the flow amount range is changed over and selected with a respective suction nozzle. Plural kinds of the suction nozzles are selected and changed over automatically according to the dimension of a change amount of an operation condition. A brushless direct motor is used as the blower motor and has a domain being operated at a chopper control duty of factor 100%.

Vacuum cleaner

In a control method and device for an AC motor, when transforming output power of a converter to AC power by an inverter and controlling the AC motor with the AC power, a source current value is determined from the value of an electric variable in the input or output side of the inverter, and the converter is controlled in accordance with the source current value. This makes the source current free from an influence of ripple components. Accordingly, even when the load of the AC motor is fluctuated abruptly, the required AC power can be applied to the converter so as to follow such fluctuations.

Control method and device for AC motor

A speed control apparatus is provided for controlling a speed of a movable equipment in such a way that the speed of the movable equipment is detected, calculates a deviation value between a detected speed of the movable equipment and a speed instruction signal, and controls the speed of the movable equipment based on the deviation value. The speed control equipment detects harmonic wave components included in the detected speed and reduces the harmonic wave components from the speed instruction signal so as to control the speed of the movable equipment.

Speed control apparatus of movable equipment

In a vacuum cleaner comprising an electric blower and a speed control unit to operate the electric blower at a variable speed, a plurality of kinds of operation control rules of the electric blower are previously stored in the speed control unit, a load current value of the electric blower is continuously detected during the cleaning and the type of the surface to be cleaned is estimated from the load current value. Thereafter, the operation control rule suitable for the estimated cleaning surface is selected from the operation control rules stored in the speed control unit and the electric blower is driven on the basis of the selected operation control rule.

Method and apparatus for operating vacuum cleaner

In speed control apparatus and method for a motor operable to drive a load whose magnitude varies over a predetermined period which use a unit for controlling voltage or current supplied to the motor such that the speed of the motor can coincide with a command speed, n pieces of data indicative of voltages or currents supplied to the motor and corresponding to n divisions of the predetermined period are independently stored in a read/write storage, at least one of the n pieces of data is corrected at the rate of each of the n divisions in accordance with a difference between the command speed and the speed of the motor, and the voltage or current supplied to the motor is controlled in accordance with at least the one of the n pieces of data, so that pulsation and noise occurring especially under low revolutions can be minimized.

Speed control apparatus and method for motors

A motor-driven compressor used as a compressor or high-pressure gas generator for a refrigerating cycle, in which the output torque of the electric motor for driving the compressor is controlled so as to make the output torque agree with the load torque required for performing compression in any revolutional angular position of the driving main shaft to thereby reduce revolutional torsional vibrations caused by disagreement between the load torque and the output torque.

Motor-driven compressor provided with torque control device

A magnetron comprising a cathode, an anode cylinder having a plurality of vanes disposed around the cathode for defining an interaction space between the cathode and the vanes, and a pair of permanent magnets disposed opposite to each other for producing a magnetic field in the interaction space. One of the permanent magnets is annular in shape, and this annular magnet is magnetized relative to the other magnet so that their same poles confront each other thereby reducing the size of the magnetron.

Magnetron comprising ferromagnetic material members axially magnetized

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Hitachiota, Japan

Tunehiro Endo