Electronic components: Buttons

Mar 8, 2021

An introduction to push buttons in electronics: how they close a circuit only while pressed, how to place one across a breadboard, and light a LED with it.

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One useful component in our circuits is a button.

It connects two parts of a circuit when the button is pressed. As soon as the button is released, the circuit is open and the current can’t circulate.

Here’s a typical button:

Black tactile push button component with four metal pins on wooden surface

Close-up view of black tactile push button showing the square body and pin arrangement

It has 2 sets of connections that can be closed at the same time. The connections are on the pins that are curved in the same way:

Push button with blue arrows indicating the two pairs of connected pins on opposite corners

There’s one way to use this component in a breadboard, and it’s to put it in the middle:

Push button placed correctly across the center divider of a white breadboard

and there’s just one way to add it, you can’t go wrong:

Push button inserted into breadboard straddling the center gap between the two sides

Side view of push button properly seated across the breadboard center divider

Then you can create a connection between 2 rows in the same part of the breadboard, like this:

Complete circuit on breadboard with push button, red LED, resistor, and red jumper wires

Overhead view of breadboard circuit showing button, LED, resistor connected with red jumper wires

In the above circuit, the LED will turn on only when the button is pressed:

Breadboard circuit with glowing red LED showing the button is pressed and completing the circuit

Tagged: Arduino · All topics

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