What’s inside a Micro Switch and How does it work?
We are going to discuss a technology that is very commonly used by automotive, medical, household and medical industries across the world in numerous markets. The technology may be very small in size but can have a greater impact on any machine or equipment to normalize its operations. Read on to know more.
For those who have started guessing out the technology, I will not let you think more on this and will straight away start talking about “micro switch”. It has a term micro in it because of the company that started its commercialization has this term in its name, Micro Switch Corporation. There are many benefits of this technology and it is available in numerous types. But today our focus will primarily be on the way it actually works.
These switches are often called snap-action switches and are extensively used in designing applications of control systems, elevator panels, vending machines, printers, refrigerators, air conditioners etc.
But the question here is that why these switches are referred to as snap action units? Well, it is because a spring that is used in these switches that tends to push the actuator for repeated movements at specific positions. Let us now break down its components to get a better view on this technology:
Actuator is an integral part of any switch which is responsible for the action movements. In a micro switch, an actuator is assembled by making three holes in it from where wire can easily pass through. It also has a button that changes the position of switch from resting state to active state once pressed.
If you open up a plastic or metallic casing of any switch, you will find a movable contact in it. A U-shaped metallic strip usually comes out of this contact serving as a spring and it is responsible to apply force to eventually change the state of actions of a switch. The primary task of the movable contact is to establish a connection between contacts which is facilitated by the bulges at both ends. Besides, there are a couple of stationary contacts as well, principally for NC and NO positions.
Common Contact Strip & Bent Strip
Another important element in a micro switch is a common contact strip that holds all parts of the contact assembly. Its upper part is joined with the casing while the lower part emerges out from which contact can be made.
Bent strip on the other hand is placed under the actuator assembly. It simply transfers the force applied by actuator to movable contact. As soon the force is released, switch comes back to resting position.
After using technical terms in abundance, things might not be easy to absorb unless you are associated with this field. Micro switches operate with the combination of the aforementioned parts.
In short, this technology may not be as simple to understand. But I have tried to illustrate the basic mechanism that will generally give you an idea about its key functionalities. Plus, it will help you understand the reasons for which it has so much significance in the technology world.