Push Button Switches Made Easy: A Practical Wiring Guide
- September 13, 2024
- 37
Push button switches: those seemingly simple buttons that grace our everyday devices, from doorbells to coffee makers, hold the power to control electrical circuits with a single press. But beneath their unassuming exterior lies a world of variety and functionality that can leave even seasoned DIY enthusiasts a tad perplexed.
This guide delves deep into the realm of push-button switches, providing a comprehensive understanding for makers of all levels. Whether you’re a curious beginner or a seasoned tinkerer, prepare to unlock the secrets of these versatile electrical components and master the art of wiring them with confidence.
What is a Push Button Switch?
Imagine a gatekeeper guarding the flow of electricity. That’s essentially what a push-button switch does. When you press the button, the gate swings open, allowing electrical current to surge through and activate a connected device. Release the button, and the gate swings shut, cutting off the current and deactivating the device. Simple, yet remarkably effective.
While the core principle remains constant, push button switches come in a diverse array of types and configurations, each tailored to specific applications:
1. Momentary Push Button Switch:
The most ubiquitous of the bunch, these switches are designed for temporary action. Pressing the button momentarily closes the circuit, allowing current to flow.
Releasing the button instantly re-opens the circuit, ceasing the flow. Think of your doorbell: a press sends a burst of current to chime the bell; release, and silence returns.
Examples: Doorbells, keyboard keys, car ignition switches (momentarily starting the engine)
2. Latching Push Button Switch:
Unlike their momentary counterparts, latching switches “remember” your command.
Pressing the button toggles the circuit between two stable states: on and off. One press turns it on; another press turns it off.
Examples: Light switches, power buttons on many electronic devices
3. Illuminated Push Button Switch:
Merging functionality with aesthetics, these switches incorporate an LED light, often serving as a visual indicator of the switch’s state or the connected device’s status.
A glowing button can signal that a device is powered on, or it can provide a handy illuminated marker in low-light environments.
Examples: Computer power buttons, dashboard switches in cars, illuminated light switches
4. Safety takes centre stage with these specialized switches:
Designed for critical situations, they often feature a prominent, easy-to-locate red button.
Pressing it instantly cuts off power to a machine or process, preventing potential accidents or damage.
Examples: Industrial machinery, power tools, assembly lines
Decoding the Language of Your Switch: Understanding the Terminals
Before we jump into the exciting world of wiring, let’s pause for a moment and familiarize ourselves with the language of push-button switches. On the underside of most switches, you’ll find a set of terminals – these are the connection points that allow you to integrate the switch into your circuits. Each terminal plays a distinct role, and understanding their functions is key to wiring your switch correctly.
The Key Players in Your Circuit:
1. C (Common): Think of the C terminal as the “main power line.” It’s like the main road that electricity takes from your battery or power source (usually the positive (+) side) to get to your switch.
2. NO (Normally Open): Imagine a doorbell button. When it’s just sitting there, not being pressed, the doorbell isn’t ringing, right? That’s because the circuit is open — like a broken wire. The NO terminal is like that doorbell button. It’s “normally open,” meaning no electricity flows through it until you press the button. Pressing the button closes the circuit, just like pushing a doorbell button makes it ring.
3. NC (Normally Closed): Now think of a light switch that’s flipped on. Electricity is flowing through the wires, and the light is on. The NC terminal is like that—it’s “normally closed,” which means electricity can flow through it freely until something stops it. When you press the button, it’s like flipping the light switch off – you’re breaking the circuit and stopping the flow of electricity.
Symbols comparing NO vs NC contacts with NO on the left and NC on the right
4. + (LED Positive) & – (LED Negative): Many push button switches come equipped with built-in LEDs to provide visual feedback. These two terminals, labelled + and -, are dedicated to the LED. The + terminal connects to the positive (+) side of the LED, and the – terminal connects to the negative (-) side, allowing you to control when the LED illuminates.
5 Pin Electrical Schematic
Wiring Your Push Button Switches: A Beginner’s Guide
Ready to add the power of “push-to-activate” to your projects? This simple guide walks you through wiring different types of push button switches.
Now that you’re familiar with the key players on your push button switch – C (Common), NO (Normally Open), NC (Normally Closed), and the LED terminals – let’s bring those concepts to life and wire up some circuits!
Before You Start: Safety First!
Working with electricity requires caution. Before you connect anything, always remember these safety rules:
• Disconnect Before Connecting: Never work on a circuit while it’s connected to a power source. Disconnect the power source before making or changing any wiring connections.
• Double-Check Your Work: A simple mistake can have unintended consequences. Before applying power, meticulously verify all your connections against the wiring diagram.
• When in Doubt, Seek Expert Advice: If you’re uncertain about any aspect of the wiring process, especially when working with higher voltages, don’t hesitate to consult a qualified electrician.
Let’s Get Wiring!
Don’t worry, we’ll keep things clear and straightforward. We’ll use simple language and provide you with easy-to-follow diagrams for each type of switch.
Wiring a 2-Pin Push Button Switch
The simplest type of push button switch, a 2-pin switch acts like a basic on/off switch for your circuit.
How It Works:
• Think of one pin as the “IN” for power and the other pin as the “OUT” of your device.
• Connect a wire from the “IN” pin to the positive (+) side of your power source (battery, adapter, etc.).
• Connect a wire from the “OUT” pin to the positive (+) side of the device you want to control (LED, motor, etc.).
• Important: Make sure your power source is OFF before connecting any wires!
• Complete the circuit: Connect the negative (-) side of your device to the negative (-) side of your power source.
Now, when you press the button, you’re connecting the “IN” and “OUT,” letting electricity flow and activating your device!
2- Pin Pushbutton Switch Wiring Diagram
Wiring a 4-Pin Push Button Switch
A 4-pin push button switch, with its built-in LED, gives you visual feedback, but did you know you can wire it in a couple of different ways?
Let’s explore two popular setups:
Setup 1: Device and LED On Together
In this configuration, the LED lights up only when the button is pressed and the device is active. Think of it like an indicator light on a power tool – it tells you when the tool is on.
Setup 2: LED Always On
Want the LED to stay lit all the time, indicating that your circuit has power, even if the device isn’t currently active? This setup is for you.
How It Works:
NO: Connect to the positive (+) of your power source.
NO: Connect to the positive (+) side of your load.
+ (LED Positive): Connect to the same pin where you connected your device (+).
– (LED Negative): Connect to the negative (-) leg of the LED.
How It Works:
NO: Connect to the positive (+) of your power source.
NO: Connect to the positive (+) side of your load.
+ (LED Positive): Connect to the C (Common)
– (LED Negative): Connect to the negative (-) leg of the LED.
4-Pin Pushbutton Switch Wiring Diagram
Wiring a 5-Pin Push Button Switch
A 5-pin push button switch is the most versatile, giving you multiple options for controlling both your LED and the connected device. This is where the NO (Normally Open) and NC (Normally Closed) terminals come into play!
Understanding the Connections:
C (Common): This is still your main power “IN” – connect it to the positive (+) side of your power source.
NO (Normally Open): Remember the doorbell? This pin only allows electricity through when the button is pressed.
NC (Normally Closed): Think of a light switch that’s already “ON.” This pin allows electricity to flow until you press the button.
+ (LED Positive) & – (LED Negative): These work the same way as in the 4-pin switch – connecting to your LED’s positive and negative legs.
The Power of Options!
With a 5-pin switch, you can create various behaviours:
• Turn on a device only when the button is pressed? ☞ Use the NO
• Turn off a device only when the button is pressed? ☞ Use the NC
• Make the LED a power indicator (always on)? ☞ Connect it to C (Common)
• Make the LED turn on only with the device? ☞ Connect it like your device (either to NO or NC depending on the desired behavior).
Refer to the Diagrams!
Because a 5-pin switch is so versatile, it’s best to follow the provided diagrams for specific wiring setups. Each diagram will clearly show you which pin to connect to your power source, device, and LED to achieve the result you want!
And there you have it! You’ve taken your first steps into the world of push-button switches and learned how to control circuits with the simple press of a button.
Remember, practice makes perfect. Don’t be afraid to experiment with different wiring setups, explore new project ideas, or even take apart old electronics to see how their switches are wired. With each connection you make, you’ll gain confidence and a deeper understanding of how circuits work.
Just remember those essential safety precautions, and most importantly, have fun bringing your electronic creations to life!