How to connect the double lights?

The double-control switch consists of two independent single-pole double-throw switches. As long as the control lines of two groups of single-pole double-throw switches are respectively connected by wires, the live wire is connected to one end of the male terminal, and the zero wire is connected to the load and then connected to the other end of the male terminal, the single-pole double-throw switches at both ends can respectively control the on-off of the load. Double control switch can control the switch of electrical appliances from two places, such as the light switch downstairs, which is convenient to turn off the lights after going upstairs.