WHAT IS A MICROSWITCH?
Before we delve into what a microswitch is, let’s understand the basic concept of a switch.
A switch is an electromechanical device used in applications where it is activated with little contact or pressure. It causes an ‘on’ and ‘off’ action where the current flow changes to produce the required operation of the appliance.
Getting down to business, the micro switch, also known as a snap-action switch, is used in almost all appliances and appliances, from alarms to washing machines. The defining quality of these microswitches is how the application of a small physical pressure on the actuator produces relatively large movements in the electrical contacts. For example, the microswitch is used in a vending machine to detect when a person places a coin.
The low cost and high durability of these micro switches make them useful in a wide range of applications, such as alarms, lamps, air conditioners, ovens, microwaves, etc.
HISTORY:
The micro switch was invented nearly 80 years ago by Peter McGall of Freeport, Illinois, USA in 1932 and has been used in almost every type of home appliance ever since.
MECHANISM:
In a nutshell, it consists of a spring lever and three connection points: current ©, N/0 (normally open) and N/C (normally closed). The spring lever is connected to the current, which with little pressure already in rest position in N/C, moves to N/O.
Now, let’s understand the concept behind this microswitch with an example:
A microswitch is often used to turn on devices like surveillance cameras where instant action kicks in when the cameras reach their furthest point of motion and start to return.
APPLICATIONS:
HOME APPLIANCES:
- It is used in rice cookers and ovens as control panels to detect if the lid is closed properly.
- Used in air conditioners to check whether the position of the door panels is closed
Many other applications include refrigerators and washing machines.
COMMERCIAL AND INDUSTRIAL APPLICATIONS:
They are used as fire sprinklers, alarms, surveillance cameras, elevators, water pipe systems, printers, automobiles, and machinery.
Cash registers: detects the opening and closing of the drawers.
Elevators: to detect whether the elevator door is open or closed and choose the floor number.
According to Dr. Larry of Honeywell, there are a few things to consider when purchasing a microswitch:
REQUEST– Know the size requirement for the form it is used for.
QUALITY: Choosing a high-quality switch is beneficial in the long run.
DURABILITY: A superior switch can work for 10 million cycles before it mechanically fails, so it is advisable to choose a switch with high reliability.
ENDURANCENote: Most microswitches are not resistant to hot and humid conditions. Therefore, it is better to choose one that has a high resilience power.
OPERATION: It should be soft and flexible during operation.