Triac - trigger circuit SCR3 with the surrounding elements constituting ordinary phase-shift trigger circuit SCR BT136S-600E, the principle is omitted here. SCR1, SCR2 selection of packaged SCR module (110A / 1000V), SCR3 selection BTl36, namely 600V triac. The circuit for inductive loads such as SCR BT137S-600E, should increase R4 SCR T435-600T, C3 RC snubber circuit and varistor RV for overvoltage protection, preventing the load off and on instantly generate high damage induced voltage thyristor triac - Detection DIP4 pin type ZC triac optocoupler use multimeter RXl profile determination triac electrode method, and also the ability to check the trigger. 1. determine T2 G very very very close and T1, T2 very far away. Therefore, positive and negative resistance between G-T1 very small SCR T435-800T, are fertile Electronics (certified), SCR provided by the Dongguan City is Wal-Electronic Technology Co., Ltd. Dongguan City is Wal-Electronic Technology Co., Ltd. (www.dgmydz.com) (www.dgmydz.com) is Dongguan, FET leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum limits to meet customer needs. Wal-electronics leader in the positive with the staff warmly welcome all inquiries negotiations to create a positive future Wal-electron better.