A miniature snap-action switch, also trademarked and frequently known as a micro switch or microswitch, is an electric switch that is actuated by very little physical force, through the use of a tipping-point mechanism, sometimes called an "over-center" mechanism.

kacon contains other products and information you need, so please check it out.

The defining feature of micro switches is that a relatively small movement at the actuator button produces a relatively large movement at the electrical contacts, which occurs at high speed (regardless of the speed of actuation). Switching happens reliably at specific and repeatable positions of the actuator, which is not necessarily true of other mechanisms. Most successful designs also exhibit hysteresis, meaning that a small reversal of the actuator is insufficient to reverse the contacts; there must be a significant movement in the opposite direction. Both of these characteristics help to achieve a clean and reliable interruption to the switched circuit.

They are very common due to their low cost but high durability, greater than 1 million cycles, and up to 10 million cycles for heavy-duty models. This durability is a natural consequence of the design.

The first micro switch was invented by Phillip Kenneth McGall in in Freeport, Illinois, under patent US1,960,020.[1] McGall was an employee of the Burgess Battery Company at the time. In W.B. Schulte,[2] McGall's employer, started the company MICRO SWITCH. The company and the Micro Switch trademark have been owned by Honeywell Sensing and Control since .[3] The name has become a generic trademark for any snap-action switch. Companies other than Honeywell now manufacture miniature snap-action switches.

In one type of microswitch,[4] internally there are two conductive springs. A long flat spring is hinged at one end of the switch (the left, in the photograph) and has electrical contacts on the other. A small curved spring, preloaded (i.e., compressed during assembly) so it attempts to extend itself (at the top, just right of center in the photo), is connected between the flat spring near the contacts and a fulcrum near the midpoint of the flat spring. An actuator nub presses on the flat spring near its hinge point.

Because the flat spring is anchored and strong in tension the curved spring cannot move it to the right. The curved spring presses, or pulls, the flat spring upward, that is away, from the anchor point. Owing to the geometry, the upward force is proportional to the displacement which decreases as the flat spring moves downward. (Actually, the force is proportional to the sine of the angle, which is approximately proportional to the angle for small angles.)

As the actuator depresses it flexes the flat spring while the curved spring keeps the electrical contacts touching. When the flat spring is flexed enough it will provide sufficient force to compress the curved spring and the contacts will begin to move.

As the flat spring moves downward the upward force of the curved spring reduces causing the motion to accelerate even in the absence of further movement of the actuator until the flat spring impacts the normally-open contact. Even though the flat spring unflexes as it moves downward, the switch is designed so the net effect is acceleration. This "over-center" action produces a very distinctive clicking sound and a very crisp feel.

In the actuated position the curved spring provides some upward force. If the actuator is released this will move the flat spring upward. As the flat spring moves, the force from the curved spring increases. This results in acceleration until the normally-closed contacts are hit. Just as in the downward direction, the switch is designed so that the curved spring is strong enough to move the contacts, even if the flat spring must flex, because the actuator does not move during the changeover.

Microswitches have two main areas of application:

• Firstly, they are used when a low operating force with a clearly defined action is needed.
• Secondly, they are used when long-term reliability is needed. This is a result of the internal mechanism and the independence of the closing force on the switch contacts from the operating force. Switch reliability is largely a question of the contact force: a force that is reliably adequate, but never excessive, encourages long life.

Common applications of micro switches include the door interlock on a microwave oven, leveling and safety switches in elevators, vending machines, arcade buttons, and to detect paper jams or other faults in photocopiers. Microswitches are commonly used in tamper switches on gate valves on fire sprinkler systems and other water pipe systems, where it is necessary to know if a valve has been opened or shut.

Micro switches are very widely used; among their applications are appliances, machinery, industrial controls, vehicles, convertible tops, and many other places for control of electrical circuits. They are usually rated to carry current in control circuits only, although some switches can be directly used to control small motors, solenoids, lamps, or other devices. Special low-force versions can sense coins in vending machines, or with a vane attached, airflow. Microswitches may be directly operated by a mechanism, or maybe packaged as part of a pressure, flow, or temperature switch, operated by a sensing mechanism such as a Bourdon tube. In these latter applications, the repeatability of the actuator position when switching happens is essential for long-term accuracy. A motor-driven cam (usually relatively slow-speed) and one or more micro switches form a timer mechanism. The snap-switch mechanism can be enclosed in a metal housing including actuating levers, plungers, or rollers, forming a limit switch useful for control of machine tools or electrically-driven machinery.

• Mercury switch
• Reed switch

Everything you should know about Micro Switch

What Is a Micro Switch?

The micro-switch is a switch that operates rapidly with a very small amount of force. The micro-switch is also called a miniature snap-action switch. It is extremely reliable, fast, and efficient to operate, and is also known as a miniature snap-action switch. It is impossible to create smart appliances without micro switches. They are used in many modern-day smart applications. Microswitches are often used as safety devices because of their reliability and sensitivity. They are used to prevent the closing of doors when something or someone is in the way and other similar applications.

The micro switch has three pins: Common (C), Normally Closing (NC), and Normally Opening (NO). Here, the Common pin is an input pin, the NC pin is Output 1, and the NO pin is Output 2.

With its tiny contact gap, The micro switch is a snap-action precision switch for logic-level and power-duty loads. The switch has options like SPDT, SPNO, or SPNC, and offers power-duty switching through silver alloy contacts. Different electrical terminations are available, and logic-level control can be achieved by silver alloy or gold-plated contacts.

How Does a Micro Switch Work?

A micro switch is equipped with an actuator that lifts a lever when pressed to move the contacts into the proper position when depressed. When pressed, micro switches often make a “clicking” sound. Often, micro switches have mounting holes so they can be quickly mounted and secured into place. Due to their long life, they rarely need to be replaced and require little maintenance since they are such a simple switch.

The working principle of a micro switch is that when it touches an object, the contacts change position. Thus, the principle of operation of this switch is mainly as follows.

The normally closed pin of the circuit is opened and the normally open pin is closed when you press the lever of the switch. In the same way, when you open the lever of the switch, then the normally closed or NC pin of the circuit will carry the current, while the normally open or NO pin of the circuit can isolate electrically.

The tipping point mechanism is also the basic feature of the micro switch. So, this feature will help to generate certain tripping points and reset points wherever the contacts will change the state.

Micro Switch Circuit

Following is the circuit diagram for the micro switch. The circuit shown below uses a micro switch to control two LEDs with a battery. The micro switch has three terminals, which are C, NO, and NC. This circuit can be connected in the same way as the circuit shown below.

There is no connection between the NO terminal and the common terminal of the switch when the lever is pressed. Therefore, the Green color will turn on once the lever is pressed.

After the lever has been raised, the common terminal and the NC terminal of the switch will be connected, so the NC terminal of the switch will not be connected, consequently the Blue color LED will turn on. Based on the application, we can use the switch in NO or NC mode.

How is a Micro Switch constructed?

In order to construct a micro switch, many different components are required, including a plunger or actuator, cover, moving piece, support, NC terminal, NO terminal, contact, and, moving arm.

Plunger

Also known as an actuator, the plunger is a type of mechanical component used to manually control a circuit by turning it on/off.

Cover

The cover of the switch is for protection against external forces.

Moving Piece

The moving part that applies the operating force to the contacts is called the actuator.

Support

This is used to help hold the micro switch in place.

NO Terminal

NO terminals, which are also referred to as normally open terminals, indicate that the switch's contacts will be open by default, thus no current will flow through the circuit if you connect them.

NC Terminal

Known as a Normally Closed terminal, the NC terminal, as the name implies, performs the opposite function of the NO terminal. The contacts are closed, allowing current to flow through the circuit.

For more Miniature Snap-Action Switchinformation, please contact us. We will provide professional answers.

Contact

The switch contact is a piece of conductive material, usually metal. Establishing or breaking electrical continuity is the primary function of this component.

Moving Arm

The moveable arm is a lever in a switch that is used for activation and operation of the micro switch.

Different Types of Micro Switches

In micro switches, we can choose the type of lever terminals based on the application. Pin Plungers, Hinge Roller Lever, Rotating Operation, Short Straight Levers, Standard Straight Levers, Long Straight Levers, Extended Straight Levers, Small Simulated Roller Levers, Standard Simulated Roller Levers, Roller Levers, and L-Shaped Levers are some of the lever terminals available. We’ll discuss some types of micro switches in the below.

Rotating Operation Micro Switch

The rotation operation micro switches are commonly used with low torque actuators. Therefore, this type of switch can be used to detect light objects such as paper currency.

Pin Plunger Micro Switch

Pin plunger micro switches are suitable for direct, short strokes, hence allowing for the detection of high-precision positions directly. Additionally, since their overtravel is the shortest, they also require consistent stoppers.

Spring Pin Plunger Micro Switch

A spring plunger micro switch has a longer overtravel than a pin plunger. However, you can use this switch for similar applications. When using this switch, make sure the load is centered on the plunger due to the slightly larger plunger diameter.

Hinge Roller Lever Micro Switch

A hinge roller lever micro switch usually has a roller connected to the lever. This makes the switch suitable for high-speed camera operation.

Leaf Spring Micro Switch

The leaf spring micro switch has a greater stroke because it is powered by a strong leaf spring. Therefore, you can use it for cams or cylinder drives at a low speed. To prevent damage and because the leaf spring has a permanent bearing point, it is essential to keep the overtravel switch in a specified application.

Panel Mount Plunger Micro Switch

This micro switch has the largest overtravel compared to other types of switches. This switch can be mounted on a panel by using a nut and a hex nut. After that, you can operate this switch either by hand or by mechanical means. Furthermore, this switch can be used with a slow-speed cam.

The differences between Micro Switch and Limit Switch

How To Maintain a Micro Switch

Maintaining a micro switch is essential to ensure its longevity and reliable operation. Here are some steps you can follow to properly maintain a micro switch:

1. Keep it clean: micro switches are sensitive to dust and debris, so they must be kept clean. It is recommended that you use a dry cloth to wipe the surface of the switch periodically. Avoid using chemical cleaning fluids such as water solutions as they may damage the switch.

2. Avoid harsh environments: micro switches should not be used in environments with explosive or flammable gases. These environments can cause damage to the micro switch and compromise its safety.

3. Inspect Contact Parts: The touch parts of the micro switch must be inspected frequently to ensure proper operation. Check that the touch of the switch is okay, that the limit distance is within the range, and that the force and speed of touch are normal.

4. Monitor voltage and current: The current and voltage can have a significant effect on the switch, so it's important to check the circuit's voltage and current at regular intervals. Make sure the voltage stability is maintained to avoid damage to the switch.

5. Periodic maintenance: In automation equipment, micro switches must be periodically checked every 2 to 3 months to observe any damage to the external power supply. This maintenance can help avoid other consequences that may result from a damaged switch.

By following these steps, you can maintain a micro switch and ensure its reliable operation. Remember that regular maintenance is essential to keep the switch functioning properly and to avoid potential damage or safety hazards.

Advantages & Disadvantages of micro switches

Advantages:

Micro switches usually have accurate performance. They are of reliable switching and inexpensive, requiring less maintenance nad can last a long life. Those switches are versatile, often resistant to water and dust, and its arcing damage can be reduced by arcing fast switching speeds.

Disadvantages:

There are some problems like low-quality parts or bad components in most of these switches. Component burns, depreciation, and sudden failure are some of the failures that can affect a Micro switch.

Micro Swicth Applications

Micro switches are versatile electronic components used in a wide variety of devices. They are often used to create timing mechanisms when combined with other devices. Micro switches are an integral part of our daily lives and can be found in home appliances, automobiles, industrial equipment, and more.

They can also be used as control switches and limit switches, used in printers to detect paper jams, and in control circuits of various devices such as small motors, lamps, and solenoids.

In addition, micro switches are used in vending machines, where they act as jam detectors and can detect coins as they are inserted into the machine. They are also important electronic components for detecting the open/closed position of valves, as safety devices in elevators, and as door interlocks in microwaves.

Micro switches play a critical role in the proper functioning of many devices, from household appliances to industrial equipment. Their versatility and reliability make them an essential component in many electronic applications.

Final Words

If you're working on a project that requires the use of micro switches, you may be considering sourcing them. Elecrow is a leading supplier of electronic components and offers component-sourcing services for various applications. 

In addition to micro switches, Elecrow offers other electronic component sourcing services such as sensors, LEDs, and more. Elecrow has a user-friendly website that makes it easy to find the components you need, and they offer fast shipping to customers around the world.

Overall, if you're looking for high-quality microswitches or other electronic components, Elecrow is worth considering. With their wide selection of products and excellent customer service, Elecrow can help you find the right components for your project and ensure that you get them quickly and at a competitive price.

Also, if you are a DIY electronics enthusiast who is keenly focused on creating projects and wants to turn your ideas into reality, Elecrow offers Partner Seller Program to help you realize your ideas, Via Partner Seller Program you can produce your own electronic products, and sell them online for commercial purposes.

 Join Elecrow's Partner Seller Program to earn your benefits!

_____________________________________________________________

Btw,  Raspberry Pi boards are popular and versatile tools for makers. The latest addition to the lineup, Raspberry Pi 5, is the most powerful version yet. Why not upgrade your projects with this cutting-edge device? Join our Giveaway campaign for Elecrow fans to win a brand new Raspberry Pi 5. Don't miss out! Good luck!

For more information, please visit Slim Solid State Relay.