Abstract: A rough and fine movement device capable of moving a mobile body with high accuracy, and a liquid supply device incorporating such a device. First and second mobile bodies are movable along guide members with a connection member connecting the mobile bodies in a relatively movable manner. A first drive mechanism roughly moves the first mobile body by a first stroke. A second drive mechanism between the first and the second mobile bodies, finely moves the second mobile body relative to the first mobile body by a second stroke. The second drive mechanism on one of the first and second mobile bodies and includes an actuator having a contactor with a first contact surface. The other of the bodies includes a second contact surface which contacts the first contact surface. At least one of the first contact surface or the second contact surface is spherical.

Abstract: A power conversion device includes a converter that converts AC power to DC power, a converter controller that controls an output voltage of the converter, an inverter that converts the DC power to AC power at a variable frequency, an inverter controller that controls an output frequency of the inverter, and a current detector that detects an AC current on an input side of the converter. It is configured in such a manner that the inverter controller adjusts a slip frequency of the induction motor in response to a fluctuation of the AC current on the input side of the converter detected by the current detector. It thus becomes possible to suppress a beat current in an output current of the inverter at the occurrence of a load fluctuation as well as a power supply voltage fluctuation.

Abstract: A current source rectifier is provided at an output of an alternating current generator, an alternating current motor is connected to an output of the rectifier via a voltage source inverter, furthermore, two arms having switching elements connected in inverse parallel to diodes are connected to the output of the rectifier, and one terminal of a direct current power source capable of a power supply and absorption is connected to a midpoint between the arms, while the other terminal thereof is connected to a neutral point of motor coils or generator coils, thereby eliminating a need for a large volumetric reactor in a direct current chopper, achieving a downsizing of the circuit.

Abstract: A brushless motor controller that controls a brushless motor by determining an energizing timing of a three-phase stator coil based on the rotational position and speed of a rotor. The controller includes a normal timing generation unit, an advancing timing generation unit, and a control switching unit. The normal timing generation unit generates a normal energizing timing. The advancing angle timing generation unit generates an advancing angle energizing timing advanced by a predetermined amount from the normal energizing timing and a final advancing angle energizing timing delayed by a delay amount from the advancing angle energizing timing. The control switching unit switches rotation control of the motor between a first rotation control executed in accordance with the normal energizing timing and a second rotation control executed in accordance with the final advancing angle energizing timing.

Abstract: A motor control system of the present invention includes an accurate electrical insulation deterioration detecting system. A voltage divider circuit is arranged between a negative DC output portion and a ground, through a normally open switch circuit. A detecting operation control section closes the normally open switch while a circuit breaker is opened, and places at least one of transistors electrically connected to a positive DC output portion into a conductive state, from among six transistors included in three arm circuits. A voltage across the first resistor is inputted as a divided voltage into a voltage comparator of a voltage comparison section. The voltage comparison section compares a divided voltage outputted from the voltage divider circuit and a reference voltage using the voltage comparator and outputs an alarm signal if the divided voltage exceeds the reference voltage.