What is a light-controlled thyristor?

What is a light-controlled thyristor?

The light control thyristor,commonly known as light-controlled thyristor,is a light control element,which has simple circuit structure and can directly drive a high-power electric circuit.The light control thyristor is composed of four layers of PNPN devices, and usually the ordinary thyristor has three electrodes:the control pole G,the anode A, the cathode K.And the light control thyristor because of its control signal from the light irradiation,so it is not necessary to draw out the gate,only the anode A and the cathode K,but its structure is consistent with that of ordinary thyristors,which is shown in Figure as the circuit symbol,internal structure and shape of the light-controlled thyristor an anode ( A ) and a cathode ( K ) are provided with an optical cable,and the optical cable is provided with a light emitting diode or a semiconductor laser as a trigger light source.But in order to be different from the graphic symbols of the photodiode,the gate is retained when drawing the graphic symbols.The voltage-current characteristic curve of the light-controlled thyristor is similar to that of a one-way thyristor,but the electric trigger of the grid is replaced by the light trigger.

When the light intensity increases,the forward turning voltage decreases.When the tube is turned on,the two ends of the tube are low in music,and at the same time in a low internal yang state.After the tube is turned on,even if there is no light,the tube will not be turned off,and the conducting state is maintained,only the reverse voltage or the anode electricity is added between the anode and the cathode when the flow is lowered to a certain value,the pipe will be turned off.