Triac Schematics - works when the anode A with a positive voltage, BG1 and BG2 tubes are in the enlarged state. At this point, if a positive trigger signal input from the control electrode G, BG2 there ib2 base flow flowing through BG2 zoom SCR BTA212, its collector current ic2 = β2ib2. Because direct collector electrode connected BG2 and BG1 base, so ib1 = ic. At this point SCR BTA412Y, then by current ic2 BG1 amplification, so BG1 collector current ic1 = β1ib1 = β1β2ib2. This current also flows back BG2 base, table positive feedback, so ib2 increasing, so the results of the positive feed cycle SCR BTA312, two tubes current surge, SCR so saturated conduction. What SCR in the circuit main purpose is Ug arrived early, thyristor of time early;? Ug late arrival, SCR conduction time later. By changing the time of the trigger pulse control on arrival Ug pole, you can adjust the output voltage on the load average UL (the size of the shaded area). In electrical technology, often alternating current half cycle for 180 °, called the electrical angle. Thus, at each positive half cycle of U2, starts from a zero value to the electrical angle of the trigger pulse arrives moment experienced by known control angle α; at each positive half-cycle of the electrical angle thyristor conduction angle called θ. Obviously SCR, α and θ are used to denote the thyristor conduction or blocking withstand voltage of the positive half cycle of. By changing the control angle α or conduction angle θ, change pulsed DC voltage across the load average of UL, to achieve a controlled rectifier. SCR BTA225 | are fertile Electronics (certified) | SCR Dongguan City is provided by Wal-Electronic Technology Co., Ltd. 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_39593080.html), for more information about the company.