| 摘要 |
PURPOSE:To extend the range of application of a transistor by providing a phase control circuit and an amplitude control circuit in parallel, jointly using both control circuits according to the range of speed and controlling the speed of the blower by using only the amplitude control circuit. CONSTITUTION:When a single-phase motor 2 is operated at low speed and at high speed, the voltage of the single-phase motor 2 is controlled only by the transistor 6 of the amplitude control circuit. When the motor is operated at intermediate speed at which the collector loss of the transistor 6 increases, speed is controlled by using the thyristor 3 of the phase control circuit and the transistor 6 of the amplitude control circuit. Accordingly, voltage applied to the single-phase motor is smoothed, and the range of application of the transistor is extended. |
