| 摘要 |
PURPOSE:To control three phase by a semiconductor switch installed to two wires, by forming a start side control signal and a delay side control signal by use of two kinds of synchronizing signals. CONSTITUTION:A synchronizing pulse generating circuit 1 outputs a start use synchronizing pulse 8 and a delay use synchronizing pulse 9, when line voltage between a line R and S of a three phase AC power supply cross at zero volt, and by being delayed by 1/4 cycle, respectively, and supplies them to a driving controlling circuit 2. Subsequently, the driving controlling circuit 2 generates a start side control signal 11 and a delay side control signal 12 which is outputted by being delayed by 1/4 cycle therefore, by both synchronizing pulses 8, 9 and an on-and-off control input signal 10. By an output of this driving controlling circuit 2, an ignition time of semiconductor switches 5, 6 such as a triode AC switch or a thyristor, etc., installed to two wires is controlled. In this way, by using 2 kinds of synchronizing signals, three phase can be controlled by the semiconductor switch installed to two wires. |
