Triac structure principle and application of typical applications zero trigger AC solid state relays (AC-SSR) internal circuitry. Includes input circuit, optocouplers, zero trigger circuit, switching circuit (including bidirectional thyristor), the protection circuit (RC absorption network). When coupled with the input signal VI (usually high), and AC load power supply voltage through the zero point, the Triac is triggered thyristor BT137S-600E, the load power is turned on. Solid state relay has a drive power of small, non-contact, low noise, anti-interference ability, pull, release time is short, long life, can be compatible with TTL\CMOS circuit can replace the traditional distinction between electromagnetic relay T1 G pole and pole ( 1) Find the T2 pole after SCR, first assumed for the rest of his legs in a Tl foot pole, the other foot for G pole. (2) the black pen then T1 extremely SCR T435-800T, red pen then T2 pole, resistance is infinite. Followed by the red pen to T2 and G short for G-pole with a negative trigger signal, the resistance value should be around ten Euro (see Figure 4 (a)), the tube has been conducting thyristor prove T435-600T, conduction one direction T1 T2. Then the red and G electrode tip disengaged (but still connected to T2), if the resistance value remains unchanged, to prove the tube after the trigger can be maintained in the ON state. SMD SCR, SCR, are fertile Electronics Dongguan City is provided by Wal-Electronic Technology Co., 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!