By single chip computer control of counter automatically generate tong 1 second stop 4 seconds of signal, make no. 5 relay output drive electric horn turns electrify.
由单片计算机控制的计数器自动产生通1秒停4秒的信号，使5路继电器输出带动电喇叭轮流通电。
2
Electrical products which have LCD time counter, Layer sensor, Three-phase AC fault protection relay and so on.