Triac Schematics - Phase Control SCR TRIAC phase control and is very similar to a DC signal available AC phase signal and the pulse wave signal to trigger, which differ when a negative voltage V T1-T2 can still trigger TRIAC. TRIAC can double conduction, can trigger the positive and negative half-cycle, use it as a full-wave power control, so in addition to the advantages of having a SCR TRIAC, more convenient AC power control. Figure 5 (a) for the TRIAC phase control circuit, only the appropriate adjustment to change the RC time constant of the excitation angle; Fig. 5 (b), 5 (c) are the excitation angle VT1-T2 and a load of 30 degrees The voltage waveform, generally beyond the control of the load than TRIAC SCR small, in general terms about 600V, 40A or less. SCR basic voltage characteristic due to the voltage rise after the avalanche breakdown voltage of the junction J2, J2 junction avalanche multiplication effect, a large amount of electrons and holes in the junction region, the N1 region SCR C106G electrons, empty P2 zone into points. Into the area of ??electronics and N1 P1 area by injecting through the junction J1 hole recombination zone N1 SCR T405-600T, similarly, P2 zone and into the hole area by N2 by injecting electrons into the junction J3 composite P2 area avalanche hit wear, enter into the P2 region of the electron and the hole area of ??each of N1 can not all composite out, so that there is the accumulation of electrons in the N1 region, there is a hole accumulation in the P2 region, resulting in the potential of the P2 region rises, N1 zone potential drop, J2 junction becomes forward biased, as long as the current slightly increases, the voltage will quickly drop SCR, the so-called negative resistance characteristics, then J1, J2, J3 three junctions are in the forward-biased SCR 2P4M, may thyristor will enter the forward conduction state ----state, this time, its characteristics and general characteristics of PN junction forward similar SCR BTA225 | are fertile Electronics (certified) | SCR by the Dongguan City is fertile Electronic Technology Limited. 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. You can also access (www.dgmydz.com/supply_details_48687755.html), for more information about the company.