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IT IS INTERESTING TO KNOW
How Does an Electric Eye Work?
A photoelectric cell is a device
that releases electricity when it
is struck by light. An electric
eye, which automatically opens
a door as you approach it, is a
good example of a photoelectric
cell at work.
As you approach a door with an
electric eye, you cut off a beam
of light trained on the
photoelectric cell. Then, as you
continue walking and leave the
beam of light, it again strikes
the photoelectric cell. When it
does, the cell sends out an
electric current that swings open
the door.
This same principle can be used to set off a burglar alarm and to
turn on a hand drier in a public restroom. In fact, almost anything that
runs on electricity can be operated by means of an electric eye!
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