How Proximity Switch Works

The Fundamentals:

A proximity switch is a device that detects an object that is close to it. It automatically opens the electric circuit when a certain object comes in contact with or close to it. These proximity switches are used in many areas today. Some of the most common uses of proximity switches are in security systems, manufacturing equipment and robotics. There are 4 main types of proximity switches viz infrared, acoustic, capacitive, and inductive.

Active Proximity Switch:

An active proximity switch distinguishes things by transferring and monitoring indications. The signals are sent immediately depending upon the distance of the object. The closer the object is, more quickly the signals will be sent. Ones the signals are sent, the proximity switch activates the circuit. E.g. an automatic door opens as soon as it detects someone in front of it.

Passive Proximity Switch:

A passive proximity switch merely supervises a particular region, unless someone manually changes it. Unlike in active switches where the signals depend on the distance of the object, in passive switches the frequency of the signals depends upon the temperature of the object. E.g. in floodlights there are passive switches attached, so that whenever someone steps in front of it, it detects the body temperature and turns the signals on.