Overview

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DJ Candi by Bongani Ngcobo, license free via unsplash.com

Our electronics talk to us through lights and displays. But how do we easily communicate back to our electronics. Ok, if touch screens don't count, the second and the oldest way to easily "tell" something to an electronics project is to turn a knob.

 

Most often, that knob is usually connected to a variable resistor, or potentiometer in electrical-speak.

The term potentiometer comes from the simple circuit shown below.

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A voltage is placed across the outer, fixed terminals and taken from ground and the middle terminal which is connected to a wiper (a movable arm on top of the resistor). At J1, the output terminals, you read with your meter a voltage from zero to the battery voltage (here 4.5 volts) which changes as you turn the shaft of the potentiometer. Potential is another name for voltage, and meter means measure - hence a potentiometer is a way of measuring/changing a voltage.

This guide will help you understand the different types of potentiometers and how you may want to use them in your projects.

While the concepts in this guide can be used with ANY microcontroller or single board computer, they will be demonstrated using the Circuit Playground Express.

Parts List

Circuit Playground Express

PRODUCT ID: 3333
Circuit Playground Express is the next step towards a perfect introduction to electronics and programming. We've taken the original Circuit Playground Classic and...

Panel Mount 10K potentiometer (Breadboard Friendly)

PRODUCT ID: 562
This potentiometer is a two-in-one, good in a breadboard or with a panel. It's a fairly standard linear taper 10K ohm potentiometer, with a grippy shaft. It's smooth and easy...

Potentiometer Knob - Soft Touch T18 - Red

PRODUCT ID: 2046
Oh say can you see By the knob's early light... Sorry - we thought that was clever.  And while it wasn't really, this potentiometer knob...

Short Wire Alligator Clip Test Lead (set of 12)

PRODUCT ID: 1592
Connect this to that without soldering using these handy mini alligator clip test leads. Approximately 4.5" overall cables with alligator clip on each end, color coded. You get 12...

If you'd like to work with a slide potentiometer, this 3.5 cm 10K linear model is nice. As usual with potentiometers and resistors, there are many types. This one is $1.29/each in single quantities at the time this guide was written from digikey.com.

1 x Digi-key Slide Potentiometer
10 kOhms 0.1W, through Hole Slide Potentiometer Top Adjustment Type, 20 mm adjust, 35 mm long
This guide was first published on Sep 16, 2018. It was last updated on Nov 14, 2018. This page (Overview) was last updated on Sep 16, 2018.