Tdk Corporation

Kabushiki Kaisha Toshiba

Tdk Electronics Company, Limited

Other

Toshiba Mitsubishi-Electric Industrial Systems Corporation

Daichi Company, Ltd.

Nihon Beam Electronics Company, Ltd.

Imperial Chemical Industries Limited

Tmeic Corporation

Toshiba Mitsubishi-Electric Indus. Sys. Corp.

Akihiko Kuroiwa

Kenryo Namba

Shiro Nakagawa

Toshiki Aoi

Kazuo Takahashi

Shigeru Asami

Toshiaki Oka

Suzuo Saito

Takaaki Ikeda

Toshihiko Suga

Mamoru Usami

Akio Hirata

Paul F Gordon

Noriko Takeda

Masanori Miyazaki

Tadao Mose

Peter J Duggan

Kenryo Nanba

Teruo Nakagawa

Stephen J Abbott

Tezumbumi Kamijo

Ritaka Nakamura

Mostafa Mamun

Kazuyuki Deguchi

A drive equipment includes a transformer, a power converter, and a control system. The transformer is configured with a primary winding and a secondary winding, and a winding of an electric motor is connected to the secondary winding. The power converter causes a current to flow through the primary winding of the transformer. The control system performs constant current control on the power converter during a period of a first stage after startup of the electric motor is instructed, to reduce a variation in a current flowing through the primary winding of the transformer, and controls the power converter through variable voltage variable frequency control of the electric motor in a second stage after the first stage.

Drive equipment and control method

In a power inverter system, an inverter unit includes first to third single-phase inverters. In the power inverter system, a reference-frequency calculating unit calculates a reference frequency of each of the first to third single-phase inverters. A reference-voltage-calculating unit calculates a reference voltage of each of the single-phase inverters. In the power inverter system, a voltage-correcting unit adds a correction voltage to the reference voltage calculated by the reference voltage-calculating unit. The correction voltage has a frequency three times as high as the reference frequency.

Power inverter system and method of correcting supply voltage of the same

A power conversion device is constituted by: a power converter that receives AC power and uses this to drive an AC motor; a control section for controlling an inverter section of the power converter; a voltage detection section that detects the voltage of the AC power source; a current detection section that detects the input current of the AC motor; and a speed detection section that detects the rotational speed of the AC motor. The control section has a vector control section that converts the current detected by the current detection section into a torque current component and an exciting current component orthogonal thereto and respectively independently controls these, and, when an electrical quantity found from the voltage detected by the voltage detection section has dropped below a first prescribed value, reduces the instruction value of the torque current component in a prescribed ratio in response to the lowered electrical quantity and, when the electrical quantity has dropped below a second prescribed value smaller than the first prescribed value, reduces the instruction value of the torque current component to zero.

Power conversion device

A controller for a wound-rotor induction motor includes a first voltage-type converter connected to a secondary winding of the motor, a capacitor for smoothing DC output thereof, a second voltage-type converter to supply an AC power supply with regenerated secondary power, a speed detector of the motor, a secondary current detector of the motor, a DC voltage detector applied to the capacitor, a speed controller for controlling the speed by the speed detector and outputting a secondary referential current, a first PWM controller to control the secondary current in response to the referential current, and to output a voltage signal by witch switching elements of the first voltage-type converter are controlled by PWM, and a second PWM controller to control a voltage output from the voltage detector in response to a referential voltage, and to control by PWM switching elements of the second voltage-type converter.

Controller for a wound-rotor induction motor

An optical recording medium has deposited on a substrate a recording layer incorporating therein a cyanine dye, preferably an indoline dye, and optionally incorporating therein an autoxidizable compound or a thermoplastic resin and/or a singlet oxygen quencher.

Optical recording medium

An optical recording medium has deposited on a substrate a recording layer incorporating therein a cyanine dye, preferably an indoline dye, and optionally incorporating therein an autoxidizable compound or a thermoplastic resin andr a singlet oxygen quencher.

Light emitting power supply circuit

A multiplexed digital control device includes a plurality of control circuits and a main signal selection circuit for selecting and outputting a specific signal among the outputted manipulated variables of the plurality of the control circuits according to a predetermined logic. Each control circuit has sub-signal selection means for comparing an internal data of the control circuit obtained as a result of control operation thereof for an identical input signal of the device with internal data of other control circuits obtained as a result of control operations thereof and selecting a specific data among them, according to a predetermined logic. The specific data selected by the sub-signal selection means is outputted as a manipulated variable of its own control system.

Multiplexed digital control device

A pit-forming optical recording medium comprises a substrate supporting a film of optically deformable recording material comprising an organic dye for absorbing optical signals of modulated electromagnetic radiation applied to the film and thereby causing corresponding deformations of the film when the signal intensities exceed predetermined threshold levels. The dye is a phthalocyanine compound or mixture of phtalocyanine compounds in which each of at least five of the peripheral carbon atoms in the 1, 4, 5, 8,9, 12, 13 or 16 positions (the '3,6-positions') of the phthalocyanine nucleus, as shown in Formula I, is linked by an atom from Group VB or Group VIB of the Periodic Table to a carbon atom of an organic radical. In preferred compounds each of the eight 3,6-positions is linked by an atom from Group VB or Group VIB, especially sulphur, selenium or nitrogen, to an organic radical. ##STR1##

A pit-forming optical recording media and process for producing the same

In a power supply circuit for operating an electroluminescent (EL) element comprising a DC power supply, an inverter connected across the power supply, and the EL element connected to the inverter, an inductor is inserted between the inverter and the EL element wherein an AC voltage is applied from the inverter through the inductor to the EL element to emit light. Another EL operating circuit includes a DC power supply, an inverter, a transformer, and a bipolar capacitor connected in this order and an AC power output on a secondary winding of the transformer is applied to an EL element to generate light. Both the circuits enables a noticeable luminance increase and power saving.

EL operating power supply circuit

Disclosed is a control apparatus for a brush-less motor, which can prevent commutation failure of an inverter for driving the motor. The control apparatus, according to the invention detects a counter EMF of the motor, and the detected counter EMF is applied to a PLL circuit. In the course of normal operation of the motor, an output of the PLL circuit is used for controlling the advanced control angle of a motor drive inverter. Any abnormality in the condition of the motor, such as that arising from an abrupt change in load of the motor, causes a sudden and substantial variation in the magnitude and phase of the counter EMF. Since the internal condition of the PLL circuit changes in response to this counter EMF variation, a signal generated by the PLL circuit is therefore used to detect the counter EMF variation. This internal signal is compared with a predetermined limit level, and when its signal level is found to exceed this limit level, operation of the motor drive inverter is stopped, whereby commutation failure of the inverter is prevented.

Control apparatus for brush-less motor

A high-accuracy position detection apparatus comprises a position detector for detecting a position signal indicating the rotation position of a motor; a coupler for coupling the motor to the position detector with a certain eccentricity; a coupling eccentricity detector, connected to the position detector, for detecting an eccentricity signal, corresponding to a coupling eccentricity of the coupler, from the position detection signal; and a true position signal synthesizer, connected to the position detector and the coupling eccentricity detector, for combining the position signal with the eccentricity signal so as to produce a true position signal which indicates the true position of the motor and is independent of the coupling eccentricity of the coupler.

High-accuracy position detection apparatus

A helper drive apparatus for a turbine drive system in which a load is mainly driven by a turbine and a helper motor is used for assisting the drive for the load, comprising: a turbine control circuit, coupled to the turbine, for controlling output power of the turbine in accordance with a turbine power reference signal; a motor control circuit, coupled to the helper motor, for controlling output power of the helper motor in accordance with a motor power reference signal; a speed control means, coupled to the turbine, for detecting a difference between a given speed reference signal and a speed signal indicating an operation speed of the turbine, and providing a master power reference signal representing the difference; and a power sharing ratio control circuit, coupled to the speed control circuit, turbine control circuit, and motor control circuit, and being responsive to a given power sharing instruction signal, for sharing the master power reference signal to the turbine power reference signal and the motor power reference signal such that a ratio between the turbine power reference signal and the motor power reference signal depends on a value of the given power sharing instruction signal.

Growing community of inventors

Tokyo, Japan

Akihiko Kuroiwa