A limit switch is a device that is used widely in electrical engineering applications. It is used to sense the presence of an object or the motion of a moving machine part. They are used in controlling machine part movements and act as a safety mechanism to ensure that the machine is working smoothly. It can also be used to count the number of times an object passes a certain predetermined point.
Limit switches consist of an actuator that is mechanically linked to certain contacts. An actuator is a device that is responsible for moving or controlling the motion of a device. Typically, it is powered electric or electromagnetic energy. This makes limit switches electromechanical devices.
Limit switches have a very wide range of applications because of their reliability, ruggedness, and ease of installation. Depending on the purpose of use, limit switches of the following types are available in the market:
- Global limit switch
Just as the name indicates, these global limit switches are designed to work all sorts of circuits across the world. These switches are designed to IEC (International Electrotechnical Commission) standards. They are made of either metal or plastic as a base.
- Medium duty limit switch
These switches are the preferred limit switches when high accuracy and long life are the priority. They are used to detect presence and absence of an object when physical contact with it is possible. These switches are used in earth moving machines, stamping machines, and conveyers among others.
- Heavy duty limit switch
A heavy-duty limit switch is used in food and beverage machinery and shipboard and dockside applications. It is housed in a rugged and die-cast body. It is often coated with a protective layer of epoxy. A wide range of mountings and actuators is available in this type of limit switch.
- Safety locking and unlocking limit switch
These switches are mainly used as a security measure to detect unexpected intruders in a particular area. It can also be used to protect equipment by tuning it to monitor that tracks the movement of certain machine components.