What is the principle of the touch delay switch in the corridor?

The touch delay switch uses the same principle as the electronic probe,

That is, a large resistor is connected in series between the human body and the power supply, so that a low-voltage current (low voltage, but not necessarily a small current) will be formed through the human body, and finally it will flow into the earth to form a trigger loop.

This can trigger the delay switch to start timing, turn on the main circuit of the lamp, and the lamp will light up. So whenever a conductor touches the touch switch, you can turn on the light (for example, holding the key with your hand, a steel spoon will do), and I often turn on the light with the key myself, which can reduce the chance of my hand touching bacteria.

it wont hurt you to try it