into different pulse duty cycle output The agencies also need to read the signals role in the implementation of drive circuit. The AC power control circuit works, about a few cycle load connected with the AC power supply, and calls for a few cycle. open and continuous cycle by changing the ratio of the average power consumption load regulation. Specific circuit in Figure 5. 220V/50Hz power to the city, to 5V voltage division below, the input operational amplifier with an input. Operational Amplifier as a zero comparator, when electricity over night, jumping changed operational amplifier output to the clock terminal D flip-flop, SCM then the output of D flip-flop input pulse signal, the output of two-way thyristor gate. Thus, only when the AC off night, SCM thyristor output signal only have an effect in other words, Only when the AC off night, or turn-off thyristor can be opened. This can greatly reduce the opening-off thyristor impact on the process, reduce opening-off loss.