| 摘要 |
PURPOSE:To apply a sine wave AC of a commercial power source to a motor and to prevent abnormal noise, vibration by controlling the amplitude of the sine wave AC while maintaining the waveform of the AC. CONSTITUTION:When a sine wave AC is applied from a power source 1, a full-wave rectified pulsating voltage is applied between C' and E. Thus, a base current IB flows to a transistor 14 according to the size of a variable resistor 12. A collector current IC flows to the collector of the transistor 14 by the IB. Since the current IC is proportional to the base current IB, if the resistor 12 is set to a certain value, the current flows in the waveform of the full-wave rectified pulsating current, i.e., sine wave current, and hence the current IC becomes a pulsating current of the waveform similar to the sine wave of the source 1. Accordingly, currents flowing to the terminals 5, 6 of a motor 4 of AC circuit side are sine wave, and the amplitudes are determined by the current IC to be controlled by the current IB. |
