... one-way SCR at anorganic whole, need not external synchronous transformer, through l-5VDC, 2-10VDC 4-20mAsignal, automatic control ... phase integration design, have power, control and fault indicationj convenient installation, input andoutput terminal photoelectric isolation, built-in overheating protection function ... ,any quertion will be appreciated. 25A-300A,three phase AC voltage regulating moudle