Thyristor

Last Update Time: 2018-12-25 14:24:38

Thyristor, a P1N1P2N2 four layer three terminal device with silicon single crystal as the basic material, is commonly known as a silicon crystal thyristor, called a thyristor (T), because it is similar to a vacuum thyristor. Also because thyristor was originally applied to controlled rectifier, it is also known as silicon controlled rectifier device, or SCR. Its shape is shown below:

P0102MN 5AA4 Allicdata Electronics

 

The advantages of thyristor are many, such as : high power control with small power, power amplification up to several hundred thousand times; the reaction is very fast, in microsecond level, turn on and off; no contact operation, no sparks, no noise; high efficiency and low cost.

The disadvantage is that the static and dynamic overload capacity is poor; it is easy to be misled by interference.

 

l  Classification of Thyristors

( 1 ) According to turn-off, turn-on and control modes, it can be divided into ordinary thyristor, bidirectional thyristor, and reverse conduction thyristor, gate turn-off ( GTO ) thyristor, BTG thyristor, temperature control thyristor and light control thyristor and so on.

 

( 2 ) Divided by pin and polarity, it can be divided into bipolar thyristor, triode thyristor and quadrupole thyristor.

 

( 3 ) According to the form of packaging, it can be divided into three types : metal packaging thyristor, plastic packaging thyristor and ceramic package thyristor. Among them, the metal packaging thyristor is divided into : bolt, flat, round shell and so on; the plastic packaging thyristors are divided into two types, radiating fin type and non-radiating fin type.

 

( 4 ) According to the current capacity, it can be divided into three types : high power thyristor, medium power thyristor and small power thyristor. In general, high power thyristors are encapsulated by metal shell, while medium and small power thyristors are mainly made of plastic or ceramic.

 

( 5 ) According to the turn-off speed, the thyristors can be divided into ordinary thyristors and high-frequency ( fast ) thyristors according to their turn-off speed.

 

l  The main parameters of the thyristor

( 1 ) Forward blocking peak voltage is that under the condition of open gate and forward blocking, the forward peak voltage can be repeatedly added to the device peak of pressure. This voltage is specified as 80 % of the forward turning voltage.


 ( 2 ) The reverse blocking peak voltage refers to the peak value of the reverse voltage that can be repeatedly added to the device at the gate opening and the rated junction temperature. This voltage is set at 80 % of the maximum reverse test voltage.


( 3 ) The rated forward average current is the continuous sinusoidal half-wave current under the condition that the ambient temperature is + 40 when the device is on ( the standard heat dissipation condition ) average.


( 4 ) Forward mean pressure drop is the average voltage drop between the anode and cathode when the device passes the rated forward average current.


( 5 ) Maintaining current is the minimum forward current necessary to keep the device on state when the gate is disconnected.


 ( 6 ) The gate trigger current is the minimum gate DC current which is necessary for the thyristor to be completely turned on when the voltage of 6 V is added between the anode and the cathode.


( 7 ) The gate trigger voltage is the minimum DC voltage applied to the gate when the gate trigger voltage is changed from blocking to on-state.

 

If you want to know more, our website has product specifications for the thyristors, you can go to Allicdata Electronics Limited to get more information.