What is the role of thyristor? What are the uses?

May 08, 2019

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Introduction: The emergence of thyristors has made semiconductor technology enter the field of strong electricity from the field of weak electricity, and has become a component used in various industries such as industry, agriculture, and transportation. So, what is the role of thyristor ? What is the reason? Make it so hot?

Introduction to thyristor

SCR, the English name is Silicon Controlled Rectifier, abbreviated as SCR, is the abbreviation of thyristor rectifier, and sometimes called thyristor. The thyristor is a high-power semiconductor device with three PN junctions and four-layer structure. It has the characteristics of small size, simple structure, strong function and high voltage resistance. It is widely used in televisions, refrigerators, radio remote control, and video cameras. , timing controllers and other equipment.

The role of thyristor 1: controllable rectification

One of the functions of thyristors is controlled rectification, which is the most basic and important role of thyristors. The well-known diode rectifier circuit can only perform the rectification function, and it is not controllable. Once the diode is replaced by the thyristor, it constitutes a controllable rectifier circuit.

In a basic single-phase half-wave controllable rectifier circuit, when the sinusoidal AC voltage is in the positive half cycle, the thyristor is only turned on when the control electrode is applied with the trigger pulse, and the voltage output is generated on the load. Therefore, by changing the time of the arrival of the trigger pulse on the control electrode, the average value of the output voltage on the load can be further adjusted to achieve the function of controlled rectification.

The role of thyristor 2: as a contactless switch

The second function of thyristor is to use it as a non-contact switch. It is often used in automation equipment instead of general-purpose relays. It has the characteristics of no noise and long life.

The role of thyristor three: switching and voltage regulation

The third function of the thyristor is to play the role of switching and voltage regulation. It is often used in AC circuits. Because of its different triggering time, the current passing through it is only a part of its AC cycle, and the voltage through it is only full voltage. Part of it thus acts to regulate the output voltage.