电动转辙机的控制电路是一个直接影响行车安全的重要电路。近年来,我国铁路的道岔电动转辙机控制电路由于安全方面的要求越来越高,而由两线制改为三线制,进而改为四线制;又因为钢轨、道岔越来越重,目前60kg/m The control circuit of electric switch machine is an important circuit that directly affects traffic safety. In recent years, the control circuit of the electric switch machine for turnout of our country railroad has become more and more demanding because of the safety requirements, and changed from two-wire system to three-wire system, and then to four-wire system. And because the rails and turnouts are heavier and heavier, Currently 60kg / m