Triac - trigger two control circuit between the respective cathode electrode and there 5V ~ 8V DC voltage pulse generation SCR, adjust potentiometer R2 can change the two thyristor controlled conduction angle SMD silicon, increasing the value of R2 to a certain extent, you can make two main SCR SCR blocked, so R2 can also play a role in the switch. Triac - thyristor voltage characteristic way into the electron and hole into the P2 region N1 respective areas not all composite out, so there are electrons accumulate in the N1 zone, there is a hole in the P2 area of ??accumulation, The results increased the potential P2 area, the potential drop zone N1 SCR BT136S-600E_ are fertile Electronics (certified) _ SCR Dongguan City is provided by Wal-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.