The fast switching, long life and high reliability of solid-state relays make it capable of working in light control system. In the field of traffic lights, the working environment of traffic lights is complicated, but solid-state relays with excellent characteristics (moisture proof, explosion-proof, anti-corrosion) can face it. And the solid-state relays can meet the requirements for sign/signal flashing traffic lights which are frequently closed and open, because they can maintain switching intervals of 10 milliseconds or longer. And in stage lighting control systems (usually applied to the production of theatre, dance, opera and other performance arts), solid state relays can work with the computer system to control multiple lights, and implement complex lighting effects to increase the atmosphere of the stage.