Photoelectric sensor

A photoelectric sensor is a special tool that helps us know if something is there or not. It uses a special kind of light that can tell us when something blocks its path.

You know how you can see things because of the light around you? Well, the photoelectric sensor does the same thing. It sends out a special kind of light wave that we can't see but can detect with a machine. When something gets in the way of that special light wave, the sensor knows that something is there.

For example, let's say we want to know if a toy is on a table. We can put the sensor on one end of the table and shine the special light beam to the other end of the table. If the toy is on the table and in the way of the beam, the sensor can tell us that the toy is there. If there is nothing in the way of the beam, the sensor will tell us that the table is empty.

Lots of machines use photoelectric sensors to help them work. For instance, a lot of automatic doors use these sensors to know when someone is walking toward the door or standing in front of it. When the sensor detects a person in its path, it tells the doors to open.