Triac - the two-way thyristor trigger circuit SCRl, SCR2 antiparallel. Then the control panel connected to this trigger circuit, it formed a simple and practical high-power variable speed circuits. This circuit is unique in that no external power thyristor control electrode of SCR BT137S-600E, as long as this circuit in series with the load power triac - trigger circuit Another feature of this circuit is two Alternating main SCR conduction, a forward voltage drop is another reverse drop SCR BT134W-600E, so there is no reverse breakdown problems. But when the applied voltage exceeds the transient blocking voltage, SCR1, SCR2 mislead pass, turned extent determined by the potentiometer R2. SCR | SCR | are fertile Electronics Dongguan City is provided by Wal-Electronic Technology Co., Ltd. Dongguan City is Wal-Electronic Technology Co., Ltd. (www.dgmydz.com) (www.dgmydz.com) strong, credible, FET and other industries in Dongguan, Guangdong has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the electronics are fertile and you hand into the brilliant, for a better future!