How to identify/judge the three poles of thyristor

How to identify/judge the three poles of thyristor

The method of identifying the three poles of a thyristor is very simple. According to the principle of P-N junction, simply use a multimeter to measure the resistance value between the three poles.

 thyristor

The forward and reverse resistance between the anode and cathode is several hundred kiloohms or more, and the forward and reverse resistance between the anode and control electrode is several hundred kiloohms or more (there are two P-N junctions between them, with opposite directions, so both the anode and control electrode are not connected in the forward and reverse directions).

thyristor, There is a P-N junction between the control electrode and the cathode, so its forward resistance ranges from a few ohms to a few hundred ohms, and the reverse resistance is larger than the forward resistance. However, the characteristics of the control pole diode are not ideal. The reverse direction is not completely blocked, and a relatively large amount of current can pass through. Therefore, sometimes the measured reverse resistance of the control pole is relatively small, which does not indicate that the control pole characteristics are not good. In addition, when measuring the forward and reverse resistance of the control pole, the multimeter should be placed in the R * 10 or R * 1 position to prevent overvoltage and reverse breakdown of the control pole.

thyristor, If the positive and negative poles of the measured component have a short circuit in the positive and negative directions, or the anode has a short circuit with the control pole, or the control pole has a short circuit with the cathode in the opposite direction, or the control pole has a short circuit with the cathode, it indicates that the component has been damaged.