What are the applications of Limit Switch?

This is a switch that is operated by the motion of a machine part. They are used to detect the presence of an object when it reaches a selected or desired point.  It is an electromechanical device that consists of an actuator which is mechanically linked to a set of contacts. The limit switch regulates the electrical circuit that controls the machines moving parts by preventing the travel of an object past a predetermined point in the mechanism. The switch activates when an object makes contact with the actuator and by doing so either breaks or forms an electoral connection.
Most limit switches fall under two categories:

1- Maintained Contact Switch
It means that when it is switched on, it stays on until you push it off (labeled On-Off-On).

2- Momentary Contact Switch
It means that when you push on, it stays on while still pressing/holding on it but upon releasing its springs back to its maintained position (labeled On (or Off).

How does a limit switch work?

The switch is electromechanically operated and consists of an actuator which is mostly adjustable.
Some actuators have a head and plunger while some, inside the housing, has an electric switch block. When the actuator is pressed or rotated, mechanical action is produced which in turn operates the switches electrical contacts.  The electoral connections are made to terminals inside the housing through a threaded opening which is suitable for a cord grip.
The limit switch electrical rating should be matched to the mechanical system it will be controlling in order to prevent any instrument from malfunctioning or failure. Before installation, one should select a limit switch based on the available space, mechanical set up of an application, the actuator style, and environmental factors.
An object must come into contact with the actuator in order to be detected.

Benefits of Limit Switch

Some benefits of Limit Switches are:

1- An object will be detected regardless of its size, shape or color.
2- Often easy to repair.
3- Low cost.
4- Due to their rugged construction, they can withstand harsh weather.
5- They use very little energy to switch multiple loads.

Limitations of Limit Switch

1- Due to the constant touching of the object, they are not desirable in applications involving food.
2- Actuation speeds are usually relatively low.
3- They can wear out due to the constant moving of machine parts.

Applications of Limit Switch

1- Its most basic use is to slow down, speed up, start or stop operations.
2- Limit switches are used as safety interlocks to prevent machine parts from moving any further when a specific point is reached for example in automatic garage doors, gates.
3- They are also used in refrigerators and microwaves for example when you open the refrigerator door, it lights up and when you close the light dies. That is a limit switch at work, that's why the light does not continue being on.
4- Limit switches are used to detect products, carriers, trolleys on a machine or an automated process. For example, the switch can be used to detect products on a conveyor belt, inform on the position of an elevator and many others.