Everything you should know about Micro Switch
Want more information on Basic Micro Switch for Sale? Feel free to contact us.
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.
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
Micro Switch
Limit Switch
Small & Sensitive
electromechanical device
AKA: miniature snap-action switch.
AKA: the end switch or position switch.
If you want to learn more, please visit our website Industrial Limit Switch Factory.
Acts as a switch to turn an electrical circuit on or off, or to close a circuit automatically in response to a mechanical load.
Functions to sense the object’s presence or absence.
A micro switch consists of two limit switches, such as NO and NC, that operate in conjunction with each other & share a common terminal.
The limit switch can be actuated by object presence or machine part motion.
The types of micro switches include: plunger, spring plunger, short spring, panel mount, leaf spring, leaf lever, roller leaf spring, and so on.
The types of limit switches are whisker, roller, lever limit, and plunger.
It has less contact gap.
It has a high contact gap when compared with a micro 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!
Elecrow Monthly RaspberryPi 5 Giveaway
Micro switch is a commonly used switching instrument , which has certain applications in aerospace, household appliances, boiler control, medical equipment, sprinkler systems, test equipment, timers and vending machines. Today, I will introduce the 5 steps of choosing a micro switch, I hope it can help you.
Step 1: Understand how the switch form factor affects other characteristics
Size matters when choosing a microswitch. Switch size is directly related to its characteristics, including current range, travel, and operating force. For example, one of the smallest microswitches on the market today measures 0.50 inches by 0.236 inches by 0.197 inches (LxWxH). While this tiny switch is suitable for detecting circuit conditions in compact circuit breakers, it typically only interrupts 0.1 to 3 amps (A) and has a short travel.
Applications that require higher currents typically require larger switches. For example, in a fuel tank application, the microswitch used to detect the liquid level needs to be able to provide a large stroke and withstand a large current. Usually in liquid level switch applications, the switch directly drives the water pump and carries a large current. This requires a large microswitch rated at 20A or 25A at 125VAC or 250VAC.
Tip: The smaller the switch size, the smaller its travel and the current that can be interrupted.
In addition, the external size of the switch also affects the operating force. Ideally, what engineers need is a switch with low operating force and high current capacity. But in fact a compromise is required between these two parameters. To maintain good contact while providing a large current carrying range, the microswitch requires a stronger spring, which increases the operating force and size of the switch. Operating forces can range from 2 grams in pressurized, pneumatic-type applications to 8 ounces in solenoid valve applications (where higher operating forces are required). One of the largest switches on the market measures 1.94" x 0.69" x 1.3" (LxWxH).
Engineers should also pay attention to the differential travel of the switch—the distance between the switch's tripped position and its reset position. Its threshold will vary according to different applications. In temperature switch applications, for example, the on/off operating points should be as close as possible and the differential travel should be as low as 0.0001 inches. However, in the application of liquid level pump, if the differential stroke is too close, it may cause the make-up pump to start and stop too frequently, shortening the service life of the pump.
Step 2: Know Your Electrical Requirements
Micro switches are usually capable of breaking currents from 5mA/5VDC to 25A/250VAC. The Micro Switch product line offers a range of products from low energy consumption to power load electrical types for a variety of applications.
Engineers must know the current and voltage ratings (AC or DC) required for a specific application to select the appropriate switch. As devices of all kinds in all industries strive for low power consumption, microswitches must be able to operate at low currents (logic level loads) and DC voltages.However, there are also applications that require switches capable of breaking high currents and voltages, such as industrial grade pump applications.
In addition to load requirements, engineers must also select the appropriate circuit. The switch contacts must be one of normally open (NO) and normally closed (NC). For NO type contacts, normally no current flows between the contacts. When the switch is actuated, the contacts are closed and the circuit is connected. For NC type contacts, current flows between the contacts normally. When the switch is actuated, the contacts are opened and the circuit is disconnected.
Step 3: Consider Environmental Conditions
Environmental requirements have a great influence on the selection of microswitches, especially in applications requiring high reliability and criticality such as industrial control and medical equipment. Understand the environmental conditions of the application, including contaminants in the air that may enter the switch, the liquid in which the switch is located, and operating temperature requirements.
For applications in harsh environmental conditions, you need to choose a sealed switch with a wide operating temperature range. The highly reliable microswitches operate from -65 degrees Fahrenheit (-54 degrees Celsius) to 350 degrees Fahrenheit (177 degrees Celsius), making them easy to handle in a variety of applications. At the same time, it should also be noted that the protection level of the switch should be at least IP67 to prevent liquid intrusion. This eliminates the need to spend a lot of time designing an enclosure that achieves the same degree of protection.
Step 4: Clarify working life requirements
Switch reliability is critical. You need to determine how many electrical and mechanical operating life an application needs? Different switches have different contact materials, housings and terminals to meet the electrical and mechanical life requirements in different applications.
A highly reliable microswitch can operate 10 million to 20 million times before mechanical failure, and 50,000 to 100,000 times under maximum load before electrical failure.
As for the slight price difference between different quality switches, you need to take into account the total cost of use. Because you're not only paying for the switch, you're also paying for the long-term, trouble-free operation of the switch. In many cases, the additional cost of using a more reliable switch is offset by a lower warranty cost during use.
Step 5: Check Agency Accreditation Requirements
Choosing switches that meet various international electrical requirements can help you simplify product design for different regions. Some major standard certifications include UL certification in the United States, cUL certification or CSA certification in Canada, ENEC certification in Europe, and CQC certification in China.
When choosing a micro switch, you need to consider multiple factors, such as form factor, load requirements, operating environment and reliability, so it is important to understand the actual application requirements: what size switch do you need? What is the required power rating? Low-voltage applications? Does the switch need to be sealed? Does the switch need to withstand extreme temperatures? Does it need international certification?
For more Roller Lever Actuator Limit Switchinformation, please contact us. We will provide professional answers.