Abstract: A motor-generator voltage controller for a turbocharger is provided with a transformer and a switching circuit mechanism. The transformer has input and output windings with the output windings being connected to the motor-generator. The input windings of the transformer have first and second portions. The winding ratio between the first portion of the input windings and the output windings is input power supply voltage: motor drive voltage. The switching circuit mechanism connects the second portion of the input windings to the input power supply when the motor-generator is operated as a motor so that the transformer functions as an invertor. The switching circuit mechanism connects the first portion of the input windings to the input powers apply when the motor-generator is operated as a generator. The motor-generator voltage controller has three transformers and three corresponding switching circuit mechanisms, one for each of a U-phase, a V-phase and a W-phase.

Abstract: A system for driving an electric machine mounted on the main shaft of a turbocharger is provided. The electric machine can function as a generator or as an electric motor. The system for driving the machine includes a positional sensor, a phase detective mechanism, a first calculation mechanism and a second calculation mechanism. The positional sensor mechanically predicts an initialized position of phase of the electric machine. The phase detective mechanism electrically predicts the initialized position of phase of the electric machine. The first calculation mechanism calculates the difference between the mechanically predicted initialized position and the electrically predicted initialized position.

Abstract: An apparatus for cutting a semiconductor crystal ingot into wafers includes a rotary blade, a first sensor, a second sensor and a computing unit. The blade is of a generally disk shape having a mark put thereon. The first sensor is stationarily located in opposed relation to the blade for sensing a distance between the blade and the first sensor to produce a first signal representative of the distance. The second sensor is stationarily disposed in opposed relation to the blade for detecting the mark of the blade to produce a second signal representative of a position of the mark. The computing unit is connected to the first and second sensors for receiving the first signal from the first sensor in synchronization with the second signal from the second sensor, and computing an amount of warp of the blade as to a fixed position thereof by using the received first signal.

Abstract: Slicing machine having a handle to be driven manually to generate command pulses. By revolving the handle, a feedtable is moved at the operator's command, enabling the positioning of a semiconductor material at the right position to start slicing. The thickness of the first wafer cut off from the material as well as other wafers, has a predetermined thickness, so that no wafer is wasted.