How to measure good or bad tirisztor?

1. Detection of one-way SCR:

The multimeter selects the resistance R*1Ω, and the red and black test leads are used to measure the forward and reverse resistance between any two pins until a pair of pins with a reading of tens of ohms is found. At this time, the pin of the black test lead is the control electrode G , The pin of the red test lead is cathode K, and the other free pin is anode A. At this time, connect the black test lead to the judged anode A, and the red test lead to the cathode K.

2. Triac detection:

Use the multimeter resistance R*1Ω block, use the red and black meter pens to measure the positive and negative resistance between any two pins, and the results of the two sets of readings are infinite. If one set is tens of ohms, the two pins connected to the set of red and black watches are the first anode A1 and the control electrode G, and the other free pin is the second anode A2.

After determining the A1 and G poles, carefully measure the positive and reverse resistances between the A1 and G poles. The pin connected to the black test lead with the relatively small reading is the first anode A1, and the pin connected to the red test lead is Control pole G.