Multi-site lighting control switch

In real life, dual-controller switches are more practical.

It is actually an exclusive OR gate.

The circuit diagram is as follows:

Images are obtained from Baidu knowledge. Http://zhidao.baidu.com/question/93332832.html)

The following three-site control switches and multi-site control switches are rarely used in real life.

There is a small defect in the picture of the Three-place control switch. To facilitate the description, the four contacts on the right of the double-Throw Switch are numbered 1, 2, 3, 4, contacts 1 and 4 are connected to the same line, and contacts 2 and 3 are connected to the same line, the vertical line on the right of the double-Throw Switch does not overlap with the middle horizontal line!