| 摘要 |
PURPOSE:To control easily the revolving speed of a motor by applying an interruption to the output phase angle of a magnetic phase shifter which controls the current at a fixed level after comparing the currents of control windings with each other and setting apparently the output phase angle at an intermediate level. CONSTITUTION:The output of a square wave generating circuit 13 is applied to a saturable transformer ST via a resistance R100. The core of the ST is selected so as to attain saturation at a prescribed intermediate phase angle. Then a motor is actuated and accelerated by a fixed current to increase the phase angle. The phase of the transformer ST is compared 15 with the phases of potentials B1 and B2 which control a thyristor gate through AND circuits AND12 and 22 and an OR circuit OR100 respectively. The output of comparison is held 16. An interruption circuit 17 receives the output of the holding circuit 16 and applies the output of a setter 14 to the gates of the TR12 and 22 of a magnetic phase shifter MA to forcibly turn on these gates. As a result, the increment of the phase angle is stopped for the thyristor of a main circuit bridge (not shown in the diagram). Then the motor is controlled by the voltage of a fixed level and set easily at an intermediate speed. Such a phase controller is suitably applied to an AC electric car of a single phase. |
