Bidirectional thyristor controlled contactor

The bidirectional thyristor is made of N-P N-P N five layer semiconducting material, and also has three electrodes.

Bidirectional thyristor is the same as unidirectional thyristor, and has trigger control characteristics. However, its trigger control characteristics are different from those of unidirectional diodes, that is, the voltage polarity between anode and cathode is different. As long as the trigger pulse is added to its gate, the bidirectional thyristor can be turned on regardless of the polarity of the pulse. Because the bi-directional thyristor can trigger at any polarity of the anode and cathode, the main electrode of the bi-directional thyristor has no anode. The two main electrodes are called T1 and T2 electrodes, and the P-type main electrode. Semiconductor materials are called T1 electrodes, and electrodes connected to n semiconductor materials are called T2 electrodes.

Gate closing (GTO) thyristor

GTO thyristor also belongs to PNPN four-layer three-terminal structure. Its equivalent circuit is the same as ordinary thyristor, and its shape is shown in Figure 2-38. Gate-off thyristors are also known as gated thyristors, or when the thyristor is turned on, the trigger signal is removed and the thyristor remains on. The characteristic of thyristor closing is that thyristor can turn off automatically when negative trigger signal is added to the gate, which not only keeps the gate current of thyristor controlling large current, but also has the ability to control turn number. Disconnection provides a convenient and wide range of applications for the application of thyristors.