Triac - trigger circuit Another feature of this circuit is alternately turned on two main SCR, a forward voltage drop is another reverse voltage drop, so there is no problem of reverse breakdown. But when the applied voltage exceeds the transient blocking voltage thyristor BT136S-600E, SCR1, SCR2 mislead pass, turned extent determined by the potentiometer R2. Triac - voltage characteristic way SCR becomes forward-biased junction J2 SCR BT137S-600E, as long as the current is slightly increased, the voltage will drop rapidly, the so-called negative-resistance characteristics. Then J1, J2, J3 three junctions are in the forward-biased SCR T435-600T, SCR will go forward conductive state ----state, this time, its characteristics and general characteristics of a PN junction is forward Similar SCR BT136S-600E, are fertile Electronics (certified), SCR provided by Dongguan City is fertile Electronic Technology Co., 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.