Abstract: A control apparatus for variably controlling a speed of an induction motor includes a voltage generator, adders, a rotating speed calculating device, a rotating direction detecting device, and a multiplier. The voltage generator is operated for a predetermined period of time at the start or restart of the induction motor to cause self-excited oscillation in a control system including the voltage generator, the induction motor and the PWM inverter. The rotating speed calculating device obtains the rotating speed data, and the rotating direction detecting device detects the rotating direction of the induction motor based on the .alpha.- and .beta.-axis components, on the stationary coordinate, of the primary current of the induction motor. And, the PWM inverter is started based on the obtained rotating speed data and rotating direction.

Abstract: In an ultrapure water production apparatus formed of a source water pretreatment system, a primary pure water system, and a secondary pure water system, the source water pretreatment system includes a biological processing device.

Abstract: A powerless emergency elevator includes guide rails (2) erected vertically; an elevator car (6) supported by a flexible rope (4) so as to be movable along the guide rails; a lock mechanism (7) provided on a top of the elevator car and biased in a locking direction for locking the elevator car to the guide rails; a power transmission path (9) extends upwardly from a floor plate (8) of the elevator car to the lock mechanism; a clutch mechanism (10) provided between the lock mechanism and the power transmission path for connecting or disconnecting the lock mechanism to the power transmission path; an auxiliary lock mechanism (11) provided on a side wall of the elevator car for releasing the clutch mechanism at evacuation and exit floors to thereby cut off the power transmission path; a handle (12) provided within the elevator car; a lock releasing mechanism (13) provided in the power transmission path for releasing the lock mechanism via the power transmission path by manipulating the handle; a lock releasing me

Abstract: A cache memory includes an address back-up register for storing the physical address of the data where errors are generated for backing up the address register, a data array address back-up register for storing data address of the data where errors are generated for backing up the data array address register, and a request code back-up register for storing a preceding request code at the time of the error generation. When an error is detected by the system controller, data is read from the main memory according to the back-up registers and the control register, EYCY register and PSEDO ACK register, of the system controller.