What is a Pushbutton Switch

Table of Contents

• What Is a Pushbutton Switch?
• What Does a Normally Open (NO) Pushbutton Switch Do?
• Is a Switch or Pushbutton an Input?
• How Does a Pushbutton Light Switch Work?
• How to Install a Mini Pushbutton Switch
• How to Install a Momentary Pushbutton Switch
• How to Install a Starter Pushbutton Switch
• How to Make a Small On/Off Pushbutton Switch
• How to Connect Two Pushbutton Switches to an Arduino Nano
• How to Replace a Pushbutton Switch for a Range Hood
• How to Wire a 4-Pin Lighted Pushbutton Switch
• How to Wire a DC Motor with a Pushbutton Switch
• How to Wire Pushbutton Switches
• Frequently Asked Questions (FAQ)

What Is a Pushbutton Switch?

A pushbutton switch is a type of switch that manually controls the on/off state of a circuit by pressing a button. When pressed, the switch changes the circuit state; when released, it usually returns automatically to its original position. Pushbutton switches are commonly used for equipment start-up, stop functions, emergency stop, and jog control.

Main Features
Operation method: Manual pressing, with contacts that are momentarily connected or disconnected.

Reset method:
Momentary (self-resetting): Automatically returns to its original position when released. This is the most common type, such as a start button.
Latching (self-locking): Press once to lock it in place, and press again to release it, such as a power switch.

Contact structure: Available as normally open (NO), normally closed (NC), or combinations such as 1NO1NC, 2NO, 2NC, and more.

Common uses
Equipment start, stop, and emergency stop
Machine tools, distribution boxes, and control cabinets
Home appliances, toys, and instrument panel buttons
Jogging and signal triggering in industrial control

Common classifications
By function: Start button, stop button, emergency stop button, jog button
By structure: Flat head, raised head, key-operated button, illuminated button, mushroom head button
By voltage: Mainly used in low-voltage control circuits, such as 24V or 220V control systems

What Does a Normally Open (NO) Pushbutton Switch Do?

A normally open (NO) pushbutton switch is open in its normal state. It closes the circuit only when the button is pressed, and opens again as soon as the button is released.

Its main functions

Starting equipment
This is the most common use. Pressing the button sends a start signal to the machine. In many control circuits, the equipment keeps running after the button is released because of the contactor’s holding circuit.

Jog control
Press to run, release to stop. This is useful for fine adjustment, positioning, or test operation.

Sending a signal or trigger
An NO pushbutton can be used to trigger indicator lights, send a pulse signal to a PLC, or perform counting and other control actions.

Safety note
Normally open buttons are usually used for start or trigger functions, not for stop or emergency stop. For stop and emergency stop, normally closed (NC) buttons are generally safer.

Is a Switch or Pushbutton an Input?

In electrical control systems, PLC systems, and computer systems, both switches and pushbuttons are considered input devices.

They send a signal to the controller to indicate whether they have been pressed, released, or toggled.

Devices that perform an action, such as lamps, motors, and relays, are considered output devices.

Simple signal flow:
Human action → pushbutton/switch (input) → controller → lamp/motor (output)

How Does a Pushbutton Light Switch Work?

Pushbutton light switches usually work in one of the following ways:

1. Momentary press-and-release type
Press once: the light turns on
Press again: the light turns off
The button itself springs back after each press, while the internal circuit changes the on/off state.

2. Latching pushbutton
Press once: the button locks and the light turns on
Press again: the button releases and the light turns off

3. Momentary lighting type
Press and hold: the light stays on
Release: the light turns off
This is commonly used for temporary lighting or test lamps.

4. Illuminated pushbutton switch
The button itself contains an indicator light. When pressed, it can switch the light on or off, and the button illumination may also turn on or off, making it easier to find in the dark.

How to Install a Mini Pushbutton Switch

The wiring methods are generally similar, but the specific function depends on the switch type.

Installation Steps

1. Mount the switch
Mini pushbutton switches are usually snap-in types that fit directly into a panel hole.
Common mounting hole sizes: 6mm / 8mm / 10mm / 12mm
Insert the switch from the front of the panel, and the retaining clip on the back will lock it in place.

2. Wire the switch

Common normally open mini button (2 pins)
One terminal connects to the positive supply or live wire
The other terminal connects to the load, such as a lamp, relay, or module
The switch acts as a break in the circuit and closes when pressed

Mini pushbutton with NO and NC contacts (3 pins)
COM: Common terminal (power input)
NO: Normally open (closes when pressed)
NC: Normally closed (opens when pressed)
In most cases, COM and NO are used.

Mini illuminated pushbutton (4 pins)
Two pins are for the switching function
The other two pins are for the built-in lamp
Make sure the lamp voltage matches the power supply, such as 3V, 5V, 12V, or 24V

3. Test after wiring
After wiring, turn on the power and test the switch.
Press the button: the light should turn on or the relay should energize
Release the button: a momentary type disconnects, while a latching type stays engaged

Safety reminder
Always disconnect power before working with 220V AC.
Low-voltage DC systems such as 5V, 12V, and 24V are safer, but short circuits must still be avoided.
Mini pushbutton switches are usually rated for low current, so they should not directly control high-power lamps or motors. Use a relay if needed.

How to Install a Momentary Pushbutton Switch

A momentary pushbutton switch only stays active while it is being pressed. Once released, it returns to its normal state.

1. Drill the mounting hole
Common mounting sizes: 5.8mm / 6mm / 8mm / 12mm
Drill a matching hole in the panel and insert the switch from the front.
The back side usually has a clip or nut to secure it in place.

2. Wire the switch

Two-pin momentary button
Connect one terminal to the positive supply or live wire
Connect the other terminal to the load
Press to connect, release to disconnect

Three-pin button (COM / NO / NC)
COM: Common terminal, power input
NO: Normally open, closes only when pressed
NC: Normally closed, opens when pressed
For most momentary-start applications, use COM and NO.

3. Typical applications
Jog control
Signal triggering
Doorbell switch
Reset button
Momentary lighting circuits

4. Safety reminder
Always turn off the power before wiring a 220V circuit.
Momentary switches usually handle low current, so do not connect them directly to high-power electrical devices.
Low-voltage DC circuits such as 3.7V, 5V, 12V, and 24V are more suitable for direct connection.

How to Install a Starter Pushbutton Switch

A starter pushbutton switch is usually configured as 1NO or 1NO1NC.

Installation Steps

1. Mount the button
Drill the correct hole in the panel, commonly 22mm.
Insert the button from the front of the panel.
Tighten the hex nut on the back to secure it.
Some models use retaining clips instead of nuts.

2. Wire the button

Scenario 1: Two terminals
One terminal connects to the incoming line (live wire or positive supply)
The other terminal connects to the contactor coil or device control input
This is the simplest series connection in a control circuit

Scenario 2: Three terminals (COM / NO / NC)
COM: Connect to the power supply
NO: Connect to the load or control circuit input. This is the terminal used for starting.
NC: Usually not used for a start button

Scenario 3: Illuminated start button
Two terminals are for the switch function
The other two are for the built-in indicator light
Be sure to match the indicator voltage correctly, such as 12V, 24V, or 220V

3. Function and use
Pressing the button closes the circuit and starts the device.
After the button is released, the button contact opens again, but the contactor holding circuit keeps the equipment running.
To stop the machine, a separate stop button is normally used.

Safety points
Always power off before installing or wiring 220V circuits.
A start button should not drive a high-power motor directly; it should control a contactor instead.
Tighten all terminal screws securely to prevent overheating caused by loose connections.

How to Make a Small On/Off Pushbutton Switch

If you want to make a simple homemade pushbutton switch without special tools, here are some easy and safe methods for low-voltage, low-current projects such as LEDs, small fans, and toy circuits. These methods are not suitable for 220V household AC power.

Method 1: Simple paper and copper-wire pushbutton

Materials
Cardboard or plastic sheet
Two thin copper wires or straightened paper clips
Tape

Method
Cut a small rectangular piece of cardboard as the base.
Fix two copper wires in parallel on the base, leaving a small gap between them so they do not touch.
Place a thin strip of copper foil or tin foil over the two wires.
Tape both ends lightly, leaving the middle free to move.

How it works
Normally, the foil does not touch both wires, so the circuit stays open.
When pressed, the foil touches both wires and closes the circuit.
When released, it springs back and opens the circuit again.
This creates a simple normally open momentary pushbutton.

Method 2: Paperclip pushbutton

Materials
2 paper clips
A small wooden block or hard plastic board
Glue or tape

Method
Straighten one paper clip and fix it to the base as the lower contact.
Bend the second paper clip into a spring shape, fixing one end and leaving the other suspended above the lower contact.
Normally, the two metal parts do not touch.
Press the spring piece to make contact; release it to break contact.

This version is more durable than the foil type.

Method 3: Reuse parts from old electronics
Remove a micro switch from an old mouse or keyboard.
Solder two wires to the correct terminals.
Mount it inside a small box using hot glue.
This gives you a compact and reliable small pushbutton switch.

Simple wiring example
Power positive → homemade pushbutton → LED or small motor → power negative
Press to turn it on or make it run, release to stop.

How to Connect Two Pushbutton Switches to an Arduino Nano

Connecting two pushbuttons to an Arduino Nano is simple. The easiest method is to use the built-in pull-up resistors, which means no external resistors are required.

Required parts
Arduino Nano ×1
Tactile pushbuttons ×2
Jumper wires
Breadboard (optional)

Recommended wiring: INPUT_PULLUP mode

Button 1
One terminal → D2
The other terminal → GND

Button 2
One terminal → D3
The other terminal → GND

How it works
The input pin is normally HIGH because of the internal pull-up resistor.
When the button is pressed, the pin is connected to GND and reads LOW.

Example code

const int btn1 = 2;
const int btn2 = 3;

void setup() {
  Serial.begin(9600);
  pinMode(btn1, INPUT_PULLUP);
  pinMode(btn2, INPUT_PULLUP);
}

void loop() {
  bool key1 = digitalRead(btn1);
  bool key2 = digitalRead(btn2);

  if (key1 == LOW) {
    Serial.println("Button 1 pressed");
  }

  if (key2 == LOW) {
    Serial.println("Button 2 pressed");
  }

  delay(50);
}

Alternative method: external pull-down resistor
Button terminal 1 → 5V
Button terminal 2 → input pin (D2 or D3) and 10k resistor to GND
In this case, use pinMode(..., INPUT) in the code.

How to Replace a Pushbutton Switch for a Range Hood

To replace a range hood pushbutton switch, the basic process is: disconnect power, remove the panel, label and disconnect the wires, replace the switch, and test the unit after reassembly. This applies to common types such as piano-key switches, tactile buttons, and complete button boards.

1. Safety and preparation
Unplug the range hood or switch off the relevant breaker. Never work on the unit while it is energized.
Prepare the following tools: Phillips screwdriver, flat screwdriver or plastic pry tool, electrical tape, phone camera, and a replacement switch of the same model.

2. Confirm the switch type
Piano-key switch: Mechanical latching type; check the number of pins and the functions, such as light, low, medium, or high speed
Tactile button: Momentary type; check dimensions such as 6×6mm and mounting position
Button board: An integrated control board; in many cases, it is easier to replace the complete board

Before removing any wires, take clear photos and note the wire color, location, and terminal number.

3. Remove the old switch
Remove the front panel or control panel carefully.
For glass or plastic panels, first remove the screws, then release the clips gently.
Disconnect the wires or plug connectors.
For terminal types, loosen the screws and label each wire.
Then remove the old switch by loosening the nut, screws, or retaining clips.

4. Install the new switch
Reconnect the wires according to the original positions.
For terminal types:
COM: Usually connected to the live input
Function terminals: Connect according to light / high / medium / low speed markings
Neutral wire usually does not go through the switch and connects directly to the motor or lamp

If it is a tactile switch on a board, solder it back carefully in the original position.

Secure the new switch firmly and reinstall any waterproof gaskets if present.

5. Reassemble and test
Reinstall the panel and tighten all screws.
Restore power and test each function one by one, including the light and each fan speed.
If the switch works correctly, secure the wires neatly with ties or tape.

Common issues and precautions
If the button does not respond well, clean oil residue around the panel opening or replace the switch.
If the functions are mixed up, the wires may be connected incorrectly.
For beginners, replacing the entire button board is often safer than desoldering individual components.

How to Wire a 4-Pin Lighted Pushbutton Switch

A 4-pin lighted pushbutton switch usually has two pins for the switch contacts and two pins for the built-in LED.

Step 1: Identify the four pins
2 pins = switch contacts, used to control the external load such as a lamp, relay, or motor
2 pins = LED terminals, used only to power the indicator light inside the button

A quick way to identify them is to use a multimeter:
The two switch pins only connect when the button is pressed.
The two LED pins do not change continuity when the button is pressed.

Step 2: Wire the switch contacts
Connect one switch pin to the live wire or positive supply.
Connect the other switch pin to the load.
Then connect the other side of the load to neutral or the negative supply.

Step 3: Wire the LED
Connect one LED pin to the power source.
Connect the other LED pin to neutral or the negative supply.

Important note
The LED section has a rated voltage, such as 3V, 5V, 12V, 24V, or 220V.
Always match the button LED rating to the supply voltage, or the LED may be damaged.

Two common wiring methods

Method A: LED always on
Connect the LED directly across the power supply so the button stays lit whenever power is present.

Method B: LED on only when switched on
Connect one LED terminal to the switch output side so the LED lights only when the switch is activated.

How to Wire a DC Motor with a Pushbutton Switch

Materials
One DC motor
One pushbutton switch (momentary or latching)
DC power supply, such as a battery or power module
Wires

Method 1: Momentary button
Suitable for jog control, testing, or fine positioning.

Wiring
Power positive → pushbutton terminal 1
Pushbutton terminal 2 → motor positive
Motor negative → power negative

Result
Press and hold the button: the motor runs
Release the button: the motor stops

Method 2: Latching pushbutton
Suitable for use as a simple power switch.

Wiring
Power positive → pushbutton → motor positive
Motor negative → power negative

Result
Press once: the motor keeps running
Press again: the motor stops

Method 3: Forward and reverse control
For forward and reverse operation, you cannot simply use two pushbuttons by themselves.
You need a DPDT switch, relay arrangement, or an H-bridge driver such as an L298N module.
Direct wiring without proper control can cause a short circuit.

How to Wire Pushbutton Switches

Here is the easiest way to remember it:

A pushbutton switch is simply inserted into a broken wire in the circuit.

In other words:
Power supply → pushbutton → device → power return

1. Basic 2-pin pushbutton wiring
Connect the positive supply or live wire to one terminal of the button.
Connect the other terminal of the button to the device, such as a lamp, motor, or relay.
Then connect the device back to the negative supply or neutral wire.

Result
Momentary button: press to connect, release to disconnect
Latching button: press once to turn on, press again to turn off

2. Three-pin button (COM / NO / NC)
COM: Connect to the power input
NO: Connect to the device for press-to-start operation
NC: Usually left unused unless a normally closed function is needed, such as stop control

3. Four-pin illuminated button
Two pins are used as the normal switch contact and are wired in series with the circuit.
The other two pins power the built-in light and must be connected to the correct rated voltage.

Simple practical rule
If you want a pushbutton to control something, place it in series with the power line going to that device.

Safety reminder
Low-current devices such as LEDs and small motors are simple to wire.
For high current or 220V AC applications, use a relay or contactor instead of wiring the pushbutton directly.
Always disconnect power before wiring.

Frequently Asked Questions (FAQ)