Explain how the photoelectric effect is used to open automatic dooes when someone approaches.
2 answers
I tried to find a web site but the only ones I found were commercial companies hawking their wares. There are several kinds of automatic doors. The one with which I am familiar works because a light beam shines on a receiver that is connected to an electronic circuit. When the beam is broken (by someone walking up to the door), the electronic circuit is activated and the door is opened.
Photo electric effect related to automatic doors how it operate