| 摘要 |
<p>A new series of portable electric tools using high frequency three-phase induction motors with built-in power electronic converter are used to power a range of portable tools like Drills, Grinders, etc. The tools operate from a single phase AC mains and a built-in power electronic circuitry converts the input supply to a three-phase, higher frequency (200 - 400 Hz) supply, which is used to drive a three-phase induction motor connected to the gearbox. A microprocessor-based controller, with a novel algorithm, generates three-phase, sinusoidal output waveforms and also provides the soft-start feature for the inverter and the motor. The entire electronics is packaged in a novel way within the housing of the tool itself. The output shaft of the motor, either directly or through a gearbox, can be connected to a wide range of tools like Drills, Grinders, Nut Runners, Screw Drivers, Impact Wrenches, Shears, Nibblers, Saws, Sanders, polishers, etc. <IMAGE></p> |
