Triac detect two short wires will then A2, G very short instant, giving G pole with a positive trigger voltage, A2, A1 between the resistance of about 10 ohms. Then disconnect the A2, G between short wiring multimeter reading should remain around 10 ohms. Interchangeable red and black pen wiring, the red pen then the second anode A2, black pen then the first anode A1. Similarly multimeter pointer should not occur BTA216 SCR deflection, resistance is infinite. With short connection to A2, G again very short moment between, plus resistance to G very negative trigger voltage, A1, A2 is between about 10 ohms. Then disconnect the A2, G extremely short wiring between the multimeter reading should remain unchanged, maintained at about 10 ohms. Comply with the above rules, instructions and test triac undamaged three pins to determine the polarity is correct. In the waveform controlled rectifier circuit, found within the forward voltage of the thyristor to withstand every half cycle, the first time issued a trigger pulse are the same, that is, the control angle α and conduction angle θ are equal, then the unijunctions relaxation oscillator exactly how to cooperate with the AC power supply in order to achieve effective control of it? When the AC voltage zero-crossing instant SCR BTA316, SCR VS forced shutdown, the relaxation oscillator is energized, they began to charge the capacitor C, repeat the process. Thus, each time after zero SCR AC voltage, the first time issued a relaxation oscillator are the same trigger SCR BTA208, this time depends on the resistance of RP and C capacitance. Adjusting the resistance of RP, can change the charging time of the capacitor C, the first time it changed Ug issued, a corresponding change of the control angle of the thyristor, so that the average value of the output voltage across the load RL is changed, to achieve the purpose of the regulator. SCR T435-800T | 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.