Sanyo Electric Co., Ltd.

Kenji Nojima

Mamoru Kubo

Yoshio Tomigashi

Keiji Kishimoto

Shigeharu Sasaki

Tetsuya Miyoshi

Kazuhisa Otagaki

Sadami Hagiguchi

Hidetoshi Inoue

Tamaoki Yuichi

In a 2-shunt system, accurate sensorless vector control can be realized without increasing shunt resistors. There is disclosed an inverter device including an inverter main circuit obtained by connecting, in a three-phase bridge-like manner, three arms formed by coupling, in series with a direct-current power source, two switching elements which perform mutually opposite on/off operations, to apply three-phase pseudo alternating-current voltages of a three-phase PWM system to an electric motor; shunt resistors connected to the direct-current power source in series with at least two of the three arms of the inverter main circuit; and a controller for detecting currents flowing through the shunt resistors in a predetermined cycle to control the on/off operations of the switching elements of the inverter main circuit based on the detected currents. The controller converts, into the current value of a specific angle range, a current value detected at a time before approximately 180&#xb0; corresponding to the specific angle range where the on-time of the switching elements is continuously not more than a predetermined value, and then uses the converted current value.

Inverter device

An object is to provide an inverter device capable of detecting the welding of a switching device in early stages, and in summary, the inverter device is equipped with a parallel circuit of a charging circuit and a switch connected between a battery and an inverter module, and comprises a capacitor charged from the battery via the charging circuit; a resistor to discharge the capacitor; a serial circuit including resistors to detect a voltage after the switch; and a diode connected between a connection point of the serial circuit including the resistors on a positive line and a connection point of the capacitor, and directed forward to the capacitor side.

Inverter device and inverter module

An object is to provide a driving device capable of detecting a current of a motor without any trouble even in a low rotation speed/low load state to continue a sensor-less vector control, in a case where the motor is driven by the sensor-less vector control, and the driving device comprises: a main inverter circuit for applying a pseudo alternating voltage to a permanent magnet type motor M to drive the motor; a current sensorwhich detects the current flowing through the motor; and a control circuit which controls the main inverter circuit. Based on an output of the current sensor, the control circuit separates the current flowing through the motor into a torque current component and a field current component to control commutation of the main inverter circuit by the sensor-less vector control. In a case where the motor is operated in a predetermined low rotation speed region and/or the motor is in a predetermined low load state, the field current component is passed in such a direction as to weaken a magnetic flux of a permanent magnet.

Driving device of motor

An object is to provide a driving device capable of smoothly shifting from a starting state to a sensor-less vector control, in a case where the device drives a motor by the sensor-less vector control, and the device includes a voltage detecting circuit which detects an induced electromotive voltage of the motor. A control circuit starts the motor by rectangular wave control. A magnetic pole position of a rotor is detected based on an induced electromotive voltage of one remaining phase of the motor detected by the voltage detecting circuit. The control circuit controls a main inverter circuit based on the detected magnetic pole position, and accelerates the motor by the rectangular wave control. In a case where a predetermined shift revolution speed is reached, the control circuit shifts to vector control by the sensor-less in which the magnetic pole position detected during the rectangular wave control is used as an initial value.

An object is to provide an inverter device capable of realizing exact protection of the winding of a motor. An inverter device for generating a pseudo alternating current by switching a direct current to drive a motor, comprises a controller that executes vector control on the basis of a secondary current applied to the motor. The controller calculates a current density from the secondary current to execute a predetermined protection operation on the basis of the calculated current density. The controller imposes a restriction on the operation frequency of the motor on the basis of the current density.

An object of the present invention is to provide an incubator with improved control performance for the temperature and humidity in an inner box. The present invention is an incubator comprising an outer box having an inner portion made from a heat insulating material, an inner box disposed in the outer box through a space defined between the inner portion of the outer box and the inner box, a heating unit disposed in the space and adapted for heating the inside of the inner box, the heating unit being constructed of a plurality of heating means disposed at least on a bottom wall and left and right side walls of the inner box, and a control unit for independently controlling each of the heating means.

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Gunma, Japan

Kenji Nojima