How Capacitors Work – A Tutorial For Hobbyists

A capacitor is a basic electronic component that works like a tiny rechargeable battery with very low capacity. Capacitors are used to create oscillators, time delays, add a power boost, and much more.

Like most components, the easiest way to understand how a capacitor works is to see with your own eyes what it does in a circuit.

Electrolytic capacitor

When I started learning electronics as a teenager, this was the first component I learned about. The way my father explained it to me made it easy to understand even though I had no understanding of the basics of electronics.

In this guide, I’ll show you how a capacitor works so that you’ll be able to understand what it does in circuits, and how you can use it in your own projects.

Covered in this guide:

Arduino Laser Module: Connecting KY-008 to Arduino

In this tutorial, you’ll learn how to connect an Arduino laser module to Arduino. I’ve used the KY-008 as an example, but most low-power laser modules will work the same way.

Blinking laser module with Arduino

Table of Contents:

The KY-008 Arduino Laser Module

The KY-008 is a laser transmitter module that creates a dot-shaped laser beam that can be used as a laser pointer or to create mini laser shows. It is compatible with Arduino, Raspberry PI, ESP32, and other popular microcontrollers.

Laser Diode: The Ultimate Beginner’s Guide

A laser diode is a cool component that you can do a lot of fun stuff with, from engraving wood to creating a light show or giving your robot eyes! They range from super cheap (or even free if you can find one in an old CD player!) to more expensive.

Most types are really easy to use too, once you learn the basics. In this article, you’ll learn the basics of laser diodes and how to use them in your own projects. In the end, I’ll show you how to create your own invisible tripwire!

Laser diode illustration

Identify Electronic Components (Quick Reference)

Not sure what type of component you’re looking at? Use this list to identify electronic components and learn what they do. 9V Battery ClipTo connect a 9V battery to your board. BreadboardThe breadboard is a very handy tool for connecting circuits. You can use it to practice, test ideas, or build simple prototypes. Breadboard wiresTo

Phototransistor – A Newbie’s Guide

A phototransistor is an incredibly useful component for detecting light in electronics projects. You’ll often find them in remote-control receivers, pulse oximeters, and line-following robots.

In this guide, you will learn what phototransistors are, how to use one, and with a simple project you can build to create an automatic light on/off switch.

Phototransistor symbol and package

What is an Integrated Circuit (IC)?

An integrated circuit is simply any type of circuit, made to fit onto a small chip. Sometimes referred to as a chip, a microchip, or an IC. It can be a microcontroller, an amplifier, a Bluetooth module, or anything in between.

An integrated circuit made in 2008 by Oyvind Dahl
The integrated circuit I made in 2008

By making a circuit on a small chip, it’s much easier to build advanced projects. Let’s say you want to make a tracking device for your car. You can find a GPS chip for positioning, a GSM chip to send text messages with the position, and a microcontroller chip to control everything. Then create a printed circuit board design to connect them all.

This would be pretty much impossible to do if you were to design everything from scratch with individual components. Integrated circuits make building circuits so much easier!

Back in 2008, I made my own integrated circuit as I was doing my master’s degree at the University of Oslo. So if you want to learn how these tiny and powerful components are actually made, from a practical point of view, (and how you can make one yourself as a hobbyist), read on!

What is a Light-Emitting Diode (LED)?

A Light-Emitting Diode (LED) is a small component that lights up when there is current flowing through it. It’s used in light bulbs, displays, lighting decorations, and much more. In electronics, it’s often used for showing the state (is the gadget turned on?).

You can see the light-emitting diode everywhere! In laptops, on mobile phones, on cameras, on toys, in our car +++.

A green light emitting diode on a breadboard

It’s a type of diode, so it only works when you connect it with its anode towards your battery’s plus terminal.

Chances are you will be working with LEDs a lot when you start learning electronics. They are cheap and simple to use, and it’s a great way to check if your circuit is working properly or not.

What is a Diode? A Guide For Beginners

A diode is a component that lets current flow in one direction and blocks it from flowing in the other direction. It has two pins; anode and cathode.

The diode symbol looks like an arrow pointing toward a line. The line represents the cathode side, and so does the line marking on the diode component itself. In the picture above, the line marking is on the left side, so that’s the cathode side.

Diode symbol and diode markings showing anode and cathode

How To Use A Breadboard – The Beginner’s Guide

A breadboard is a simple and useful tool for connecting a circuit. It’s really useful for beginners as you can easily experiment and test out circuits without soldering. But it’s also useful for more experienced people since you can prototype an idea, or parts of a circuit, quickly.

I often use breadboards in my work.

Want a quick introduction to the breadboard? Check out my short video below (2:30) or continue reading.

Capacitors in Series

Capacitors in series are capacitors that are connected one after the other. The result always becomes a capacitance that is lower than the lowest value. In this guide, you’ll learn why this is the case and how to calculate their combined values. And I’ll also throw in a simple rule of thumb that you can

Capacitors in Parallel

When you connect capacitors in parallel, you connect them alongside each other. And the result becomes a capacitance with a higher value. In this guide, you’ll learn why it works like that, how to calculate the resulting capacitance, and some examples of this in practice. As you’ll soon see, this is actually very simple. How

The Useless Halloween Machine

This year’s Halloween project is a useless machine built with 555 timers. It’s a coffin with a switch. When you flip it off, a dark force rises from the coffin and flips it back on.

Controlling a Servo with 555 Timers

The idea for this project came after we published the simple 555 PWM circuit that controls a DC motor using a PWM signal created by a 555 Timer. I started thinking about the idea of controlling a servo instead.

After some experimentation, I realized that the frequency changed too much when I changed the duty cycle. So my servo would only move at random times.

How to adjust the brightness of an LED

Do you want to adjust the brightness of your Light-Emitting Diode (LED)? If we break it down to the most basic, there are two ways to change the brightness of an LED:

  • Changing the resistance value.
  • Turning it on and off fast (Using PWM).

Below I’ll explain the two options and show you circuits you can build.

Arduino Shield Project LED matrix

How to Build a Touch Sensor Circuit

In this project, you will build a touch sensor circuit. It’s a cool and simple circuit that allows you to control an LED with the touch of a finger. And you only need three components, how cool right? You can build this circuit if you’re a total beginner. The Touch Sensor Circuit Diagram You only

Voltage Divider Tutorial For Beginners

A voltage divider is a circuit that creates a smaller voltage from an input voltage by using two resistors. You’ll see it in both simple and advanced circuits all the time. Here’s the basic setup:

The basic voltage divider circuit

It is useful for example for reading sensors like thermistors and photoresistors since it converts an unknown resistance into a voltage. Or to reduce the volume of an audio signal via a potentiometer.

You can find the output voltage by inserting the resistor values and the input voltage into the following formula:

V_{OUT} = \frac{R2}{R1+R2} \cdot V_{IN}

Or you can use the calculator a little bit further down on this page.

Once you know how it works, it’s much easier to see how circuits work. And it will let you calculate voltages at many different points in a circuit – which is often needed to understand it.