Voltage detect of three phase AC the warning of over-voltage under-voltage lost phase and power failure two-way AC circuits switch full-automatically .

三相交流电压检测，过压、欠压、缺相、停电告警，全自动 双路交流前 换功能；

In order to control the AC with the chopping method MOSFET is used to design a pair of two-way electronic switch and an AC Buck-Boost circuit is formed .

采用MOSFET构成一对 双向导电型电力电子 开关，对交流电进行斩波控制，形成交流Buck-Boost电路。

We need a two-way switch .

我们需要一个 双 路 开关。