Let’s first look at the working principle of the traditional double control switch, as shown in the figure below.

 

We assume that the room has a single-open dual-control switch to control the lights, S is placed at the entrance, and S1 is placed at the bedside.

 

After understanding this, we will know how to upgrade to smart switches and transform smart light controls.

 

We just need to buy a smart switch. How to operate when upgrading?

 

When the power is turned off, check whether there is a neutral line in the switch panel. Generally speaking, there is not, but of course the possibility cannot be ruled out. If you have one, you can buy a zero-fire version of the smart switch and just turn it on. If you don’t have one, you need to buy a single-fire version of the smart switch.

 

When you buy it back, you have to install it, and the installation still requires you to cut off the power.

 

We want to transform it into a smart switch. We need to understand that if we only install one smart switch, we need to replace one of the previous push switches, and then change the wiring of the other one so that it loses its switching function. The reason why we do this is that we need the smart switch to be stable enough to stay online.

 

For example, if we want to replace S with a smart switch, we need to replace the L wiring of S to the smart switch L. If there is a neutral line, place the neutral wire to the smart switch N. If you can distinguish the controls of L1 and L2 Line, you only need to take one line as the control line, that is, place L1 or L2 at L1 of the smart switch. If you can't tell the difference, just combine L1 and L2 of S and place them at L1 of the smart switch. Then there is how to set up S1 so that it loses its switching function. Be able to distinguish the control lines of L1 and L2, and place the L1 or L2 you took at the L position of S1. If you can't tell the difference, combine L1 and L2 and place them at L of S1. In this way, we have completed the upgrade of the traditional dual-control switch into a smart switch.