How to identify the three poles of thyristor

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How to identify the three poles of thyristor [Copy link]

The method to identify the three poles of thyristor is very simple. According to the principle of PN junction, you only need to use a multimeter to measure the resistance between the three poles. The forward and reverse resistance between the anode and cathode are over several hundred kilo-ohms, and the forward and reverse resistance between the anode and control electrode are over several hundred kilo-ohms (there are two PN junctions between them, and in opposite directions, so the anode and control electrode are not connected in the forward and reverse directions). There is a PN junction between the control electrode and the cathode, so its forward resistance is in the range of several ohms to several hundred ohms, and the reverse resistance is larger than the forward resistance. However, the control electrode diode characteristics are not ideal, and the reverse direction is not completely blocked, and a relatively large current can pass through. Therefore, sometimes the measured control electrode reverse resistance is relatively small, which does not mean that the control electrode characteristics are not good. In addition, when measuring the forward and reverse resistance of the control electrode, the multimeter should be placed in the R*10 or R*1 position to prevent the reverse breakdown of the control electrode due to excessive voltage. If it is measured that the positive and negative poles of the component are short-circuited in the forward and reverse directions, or the anode and the control electrode are short-circuited, or the control electrode and the cathode are short-circuited in the reverse direction, or the control electrode and the cathode are open-circuited, it means that the component is damaged.

Source: Venusstar Electrical Information