| 摘要 |
<p>The driver circuit (10) comprises a first triac or the like (11) for connection in series with the stator winding (5, 6) of the motor between the terminals (12, 13) of an alternating-current voltage supply, the gate of the first triac (11) being arranged for connection to an intermediate point (C) of the stator winding (5, 6) of the motor (M). A second triac or the like (15) is connected between the intermediate point (C) of the winding (5, 6) and the terminal (13) of the voltage supply to which the first triac (11) is connected. A control circuit (15-27) is connected to the gate of the second triac (15) and, each time the motor (M) is connected to the voltage supply, initially makes the second triac (15) conductive and consequently cuts off the first triac (11) for a predetermined initial period of time, and cuts off the second triac (15) and allows the first triac (11) to become conductive after this period of time. During the predetermined initial period of time, only a portion of the winding (5, 6) of the motor (M) is connected to the voltage supply (12, 13) by means of the second triac (15) and, after this period of time, the whole winding (5, 6) of the motor is connected to the voltage supply (12, 13).</p> |
