Working Of Limit Switches

Feb 24


Kunal Sutar

Kunal Sutar

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Presence Sensing is the act of identifying the presence or absence of any material with a contact or non-contact sensing device.


. The equipment or processes is controlled by the sensors which produces an electrical output signal.

Limit switch manufacturers make these devices which are a type of sensor that detect presence and absence. Particularly,Working Of Limit Switches Articles mechanical limit switches can be activated mechanically. In context, they have some sort of mechanical equipment like arm, lever, knob, plunger, etc., which can be physically—or mechanically—activated by making contact with another object. Whenever the object makes contact with the actuator of the switch, it ultimately pushes the actuator to its “limit” where the state of the contacts is changed. There are different varieties of sensors/switches which exist in market, includes proximity sensors, light sensors, electric switches, among others.

In industrial applications for detecting the presence or position of objects, mechanical limit switches are extensively used as contact sensing devices. The operation of the device itself derives the term limit switch. Whenever a particular object or target makes contact with the switch operator, it will eventually move the elevator to its limit where the electrical contacts change state.

The electrical contacts are either opened (in a normally closed circuit) or closed (in a normally open circuit) by performing this mechanical action. Inductive proximity, capacitive proximity, and photoelectric sensors achieve this same method through noncontact sensing.

In its simplest form, a limit switch is a “switch” produced by these manufacturers that can be mounted into isolated locations so that it is actuated by a thing other than a human operator. Some basic functions of limit switches that manufacturers ensure are:

  1. Sensing presence/absence.
  2. Sensing variety of measure.
  3. Sensing positioning & travel limit
  4. Breaking a live circuit when dangerous circumstances rises.
  5. Sensing speed

…and hundreds of other submissions

Mechanical limit switches can be found in any industrial or commercial application where detection or safety is needed.

Limit switches manufacturers believe them to be a hands-on solution for sensing in most situations.

Benefits of Limit Switches

  1. Can be used in almost any manufacturing location.
  2. Very exact in terms of accuracy and repeatability.
  3. Consume little electrical energy.
  4. Can switch loads with high inductance.
  5. Can switch numerous loads.

Limit Switch Functional Parts :

Mostly, limit switches contain the following functional parts in one form or another.

Actuator/Operating Head

The actuator is the part of the switch whose function is to contact physically with target. To open or close the electrical contact of the switch, the actuator is attached to the operating head upto perpendicular motion in some switches.

Switch Body

The constituent comprising the electrical connection device.


This component contains the terminal screws or screw/clamp assembly which are necessary for wiring purposes. While there are a number of different styles of limit switches available in the market today, this physical will describe two classes of limit switches — standard industrial oil tight and precision switches.