Push button switches are must-have components in most electrical circuits because they help regulate electrical current flow. Therefore, knowing how to wire a push button switch is vital, especially if dealing with the 5-pin type.
Let’s look at the various wiring steps for 2-pin, 4-pin, and 5-pin push button switches to make your project easier.
Table of Contents
- What Is a Push Button Switch?
- How To Wire a Push Button Switch
- Push Button Switch Terminal Types
- 5-Pin Push Button Switch Color Codes
- Wrap Up
What Is a Push Button Switch?
Push button switches are open-tactile switches that can complete or disconnect circuits by pressing a button. They operate using a latching or momentary action and must have a sturdy build quality to withstand multiple finger presses.
Latching push button switches stay in their next state when pressed, then return to their original position when you press them again. Such switches are ideal for controlling lights and AC or electric fans.
A set of push-button switches for a coffee machine
But momentary push button switches only maintain the next or secondary state when pressed. Once you release the switch, it returns to the original state, usually off. Momentary switches are ideal for keyboards, car horns, and doorbells.
The pressing surface can be flat or ergonomically designed to fit your finger for easy pushing.
How Push Button Switches Work
These switches are available in NO (Normally Open) and NC (Normally Closed) contact configurations. But all have a similar internal construction.
When you press the button of an “NO” switch, it depresses an internal spring and latches when it touches stable contact points at the bottom to complete the circuit.
The NC switch has the reverse contact placement. Therefore, when you press the button, it leaves the contact points at the top, opening the circuit. Once you press the button again, the spring retracts, pushing the button to its original position on the contacts.
Momentary switches don’t have a latching mechanism. But they operate the same way.
How To Wire a Push Button Switch
Push button switches come in different types, categorized by their number of pins or terminals. So, let’s look at the wiring steps for these types, which include 2-pin, 4-pin, and 5-pin.
2-Pin Push Button Switch Wiring
Push buttons with a pair of pins/wires are the most basic type because they handle only two operations. These are turning the circuit on and off.
Wiring this switch is simple because it sits between the positive terminal of the power supply and the load. The negative pole connects directly to the load device.
Various push button switches with their contact pins
If the push-button switch is the NO type, depressing it will turn on the load. But if it is an NC type, it will turn off the power supply to the load device.
4-Pin Push Button Switch Wiring
With two pairs of pins, you have to identify the function of each pin first. Most switches have two pins for powering the load and the other two for linking to the power source. The first two power source pins have an internal connection, and so do the two load pins.
So the switch is like two 2-pin types in the same housing, meaning you can control two load-device circuits concurrently.
A 4-pin push button switch
Follow these steps when wiring this tactile switch.
- Connect the switch’s power source pins to the power supply’s positive pole.
- Link the other pins to the load. Remember, the switch can have either NO or NC contact pins. If you want the load/end device to work when you press the button, use an “NO” switch. But if you want it to turn off after pressing the button, use an “NC” switch.
- Connect the neutral wire from the load to the power source’s negative terminal.
5-Pin Push Button Switch Wiring
5-pin switches are the most typical type for projects because they have a built-in LED light that glows the translucent material around the button.
Most of them have a round button shape with a variety of colors to choose from to make the button visible in the dark.
Wiring this switch can be slightly complicated, but we’ll look at four ways to do it to control the internal and external circuits. The pins are C (common), NC, NO, and two LED light terminals (+ve and -ve) for the built-in LED.
Method 1
Connect the C pin to the positive wire from the battery, then connect the load, such as a lighting system, to the LED +ve terminal. Link the NO pin to the LED +ve terminal to keep the power off in both circuits when the button is in its regular position.
A push button switch with an internal LED
Next, connect the negative pole from the power source to the LED -ve pin on the neutral side, then to the negative load terminal.
When you press the button, the built-in LED light and the load will turn on. Releasing or pressing it again to the off position switches off both circuits.
Method 2
Connect the positive wire from the battery to the common terminal, then the LED +ve pin to the NC pin. This NC terminal then goes to the positive load wire. The negative connections remain the same as above.
In this configuration, the LED and load circuit will be on when the push button is in its regular position. And it will cut off the power when pressed.
Method 3
This method still draws power through the C pin, which links to the LED +ve terminal. The load electronic device draws the switched power from the NO pin, and the negative power connections remain the same.
A 5-pin push button switch
This configuration keeps the load circuit off while the LED is on when the button is in its regular state. When you press the button, the built-in LED and the load circuit will be on.
Method 4
Method four is an inverse of method three because it keeps the internal LED and external load powered when the push button is in its regular position.
But when you press it, the load device goes off while the internal LED remains on.
You can create this operation by connecting the positive battery terminal to the C and LED +ve pins.
From there, the load draws power from the NC pin. The negative terminals remain the same as earlier.
Push Button Switch Terminal Types
These switches can have a pin, plug, wire button, screw, or wire (soldering/crimping) terminals, each with different benefits and drawbacks.
Pin Terminal
Metal pins simplify the insertion or mounting of the switch into a socket, breadboard, or circuit board hole. Removing them is also easy. The standardized pin orientation makes such devices widely compatible.
However, the pins can become loose or bend over time, especially with repeated insertion and removal into socket slots. These can also cause short-circuiting if improperly insulated.
A mini push button with pin terminals
Plug Terminal
Plug terminals resemble pins because they have similar properties. Therefore, their usage, advantages, and disadvantages are the same.
Screw Terminal
With a screw terminal, you can tighten or loosen the grip around an attached wire to secure or release the electrical connection.
Such power links are sturdy, reliable, and can safely handle high voltages and currents. However, they can damage the wire, PCB, or device if overtightened.
Wire Terminal
These terminals require crimping or soldering to the load device, giving you the flexibility to customize the connection.
The joints can also handle high voltages and current, but you need tools and soldering/crimping skills to create reliable joints.
Multiple tactile push buttons inserted in a breadboard
Wire Button Terminal
Wire button terminals come with copper wires already attached to the switch. So you cannot access the terminals.
This connection is usually waterproof and simplifies installation because you don’t need sockets or mounting holes. However, this connection limits customization options.
5-Pin Push Button Switch Color Codes
If you use a 5-pin push button switch with the wire button terminals, it will come with copper wires already connected. These wires have a color code that implies these functions.
- Red wire: Powers the internal LED
- Black wire: Ground wire for the internal LED
- Green wire: Common terminal or public wire
- Blue wire: Normally Open (NO)
- Yellow wire: Normally Closed contact (NC)
Wrap Up
Wiring push button switches is a simple process, and the 5-pin type is more interesting to handle due to its internal LED.
Although it requires slightly more work, the device is still easy to wire. Follow the steps explained earlier, and you’ll be good to go.
Check out this headlight switch explainer to learn about this specific car switch and how it operates. And comment below if you need further clarification.
