| 摘要 |
PURPOSE:To improve the breakdown voltage of a transistor controlling voltage and the loss of a collector by a method wherein a resistor or a coil are connected in parallel with the primary voltage control circuit and in series with a motor. CONSTITUTION:One terminal of a rectifying circuit 4 is connected in series with an AC power source 1 and a single-phase induction motor 3. A transistor 5 and a base circuit 6 are connected to the other terminal of the rectifying circuit 4, and the number of revolution of the motor is controlled by the voltage which the transistor bears. Resistors 8, 9 and a coil 7 are connected in parallel with the transistor 5 and in series with the motor. Thus, the maximum voltage applied to the transistor and the loss of a collector decrease to three fourths if the impedance of the resistors and the coil is taken as the threefold of the impedance of the motor. The breakdown voltage and allowable loss increase equivalently, and use having scope to rating is enabled. |
