Discrimination thyristor (SCR) SCR pin pin discrimination by the following methods: first with a multimeter to measure the resistance R * 1K block between tripod, the resistance of the feet were small and cathode thyristor control 2P4M, left kick to the anode. Then multimeter R * 10K block, with fingers anode and the other foot, and do not let the feet touching, black pen then the anode, the red pen then the rest of the foot SCR C106D, such as the swing to the right hands SCR C106M, explain the red pen connects the cathode, compared to the control electrode does not swing. Triac thyristor structure principle and application of ordinary (VS) essentially belongs to the DC control devices. To control the AC load, must be two parallel SCR thyristor reverse polarity, so that each SCR control a half-wave, for which required two separate trigger circuit, use is not convenient enough. Triac is evolved on the basis of ordinary thyristor, it can not only replace two anti-parallel thyristors polarity, but only a trigger circuit, is the ideal communication switching devices. Its English name that triac TRIAC AC switch means. SCR C106M, are fertile Electronics (certified), SCR provided by the Dongguan City is 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.