How Transistors Work – A Simple Explanation

The transistor is a simple component that you can use to build a lot of fun projects. In this hands-on guide, you’ll learn how transistors work so that you can use them in your next circuit.

And it’s actually pretty easy, once you learn the basics. I’ll focus on the two most common transistors here; the BJT and the MOSFET.

NPN transistor on a breadboard

The transistor works like an electronic switch. It can turn a current ON and OFF. A simple way to think about it is to look at the transistor as a relay without any moving parts. A transistor is similar to a relay in the sense that you can use it to turn something ON and OFF.

But a transistor can also be turned partly on, which is useful for building amplifiers.

The Pull-Up Resistor: How It Works and Choosing a Value

The pull-up resistor is very common and you’ll see it in digital circuits all the time. It’s just a resistor connected from an input up to VDD, the positive supply of the circuit.

For example on digital inputs on an Arduino. Or the input of digital chips such as the 4000-series IC.

Pull-up resistor example circuit

Pull-up resistors are used to make sure you have a HIGH state on the input pin when the button is not pushed. Without one, your input will be floating, and you risk that the input randomly changes between HIGH and LOW as it picks up noise in the air.

Cap Half Full #6 – Repairing an old amplifier

In this episode, we repair an old Sanyo amplifier. In this episode, we find an old amplifier in the trash and we try to repair it. Will we able to? Listen and find out. Listen to the Podcast Show Notes

The Most Common Schematic Symbols Used in Electronics

To be able to read schematics you must know the basic schematic symbols used in electronics. But you don’t need to memorize them all. To start with, it’s usually enough to know the battery, resistor, capacitor, transistor, diode, LED, and switch.

Later when you come across symbols you don’t know, you can come back here to identify what it is.

Below is an overview of the most used symbols in circuit diagrams.

What is Ground in Electronic Circuits?

An example circuit with lots of connections to ground

When you start learning about circuits, you’re bound to ask “what is ground?” at one point or another. Are you actually suppose to connect your circuit into the ground??

First of all: grounding in electronics is different from the earth connection in wall outlets (although they sometimes are connected).

How to Use an Oscilloscope – The Beginner’s Guide

How to use an oscilloscope

Knowing how to use an oscilloscope is very useful when building electronic circuits. When your circuit is not working, it will help you figure out what is going on.

I learned how to use an oscilloscope pretty much on my own. The first time I tried one, I only got some simple instructions, then I was left to myself to figure things out.

But I found that it wasn’t really that hard…

The oscilloscope can be a bit overwhelming with all its functions. But you don’t need to know every detail of it. You can actually come a long way by knowing just a few simple things.

So I want to pass those simple things on to you so that you can start using an oscilloscope on your own.

Learn Electronics With These 10 Simple Steps

Do you want to learn electronics, so that you can build your own gadgets? There is a ton of resources on learning electronics – so where do you start?

And what do you actually need?

And in which order?

Components on a stripboard

If you don’t know what you need to learn, you can easily waste a lot of time learning unnecessary things.

And if you skip some of the simple but crucial first steps, you’ll struggle with even the basic circuits for a long time.

How to Create Gerber Files in KiCad

Gerber files are actually images of the different layers of your Printed Circuit Board (PCB). And it’s a universal way of sending your design to a PCB manufacturer. In this tutorial, I’ll show you how to create these files in KiCad.

Gerber files viewed in KiCad's gerbview
Example of two gerber file layers viewed in KiCad

PCB Design: How to Create a Printed Circuit Board From Scratch

To design a Printed Circuit Board (PCB), you need to draw holes, pads, and wires for your circuit.

Illustration of PCB design

When you’re done drawing the board, you can either send the design to a manufacturer that will make it for you (it’s actually pretty cheap) – or you can etch it yourself at home.

This skill is called PCB design and it’s easier than many think.

In this guide, I’ll lay out all the steps for you. And once you’ve gone through these steps one time, the second time everything is much easier.

The Soldering Tools That Make Your Life Easier

The most important of the soldering tools is the soldering iron

The only soldering tools you really need to get started with soldering are a soldering iron and some solder. If you just want to get started, that’s what I recommend you get.

Even though you can do a lot with just a soldering iron, getting a few extra tools could make things easier.

In this article, I’ll show you what the basic soldering tools are.

The Sunrise Wake-Up Alarm

In this tutorial, you’ll learn how to build an sunrise wake-up alarm. It's a light-sensitive circuit that will activate a buzzer when you have light shining directly on it. Place it in your window at night and the alarm will activate in the morning when the sun rises.

Tips: This trick will help you understand circuits

Are you struggling to understand circuits and see how currents flow?

I wrote this based on an interaction I had with Gary.

And maybe it can help you.

I was developing some new material for a course.

And I used Gary as my test subject. He’s an adult British gentleman with no electronics background whatsoever.

He told me that if he could understand this, then anyone could.

Where To Buy Electronic Components?

Buy electronic components online

There are a bunch of places to buy electronic components.

Myself, I love to go to a brick-and-mortar store to buy components, because then I can get them without waiting. Unfortunately, many cities don’t have these anymore. So what do you do?

Tips: How to combine components?

“How to combine components to get a specific function?”

Many people ask me this.

But that’s like if you want to learn the piano and ask:

“How to combine notes to play a specific song?”

What you need to do to learn to play the piano is to practice playing the piano.

What Is an Inductor? A Practial Guide for Hobbyists

The inductor is a simple component, and how it works is also pretty simple. The only problem is that most explanations do not explain it in a simple way.

So, what is an inductor? Well, it’s kind of a strange component. At the most basic level, it is just a coil of wire. And it’s easy to make one – just make some loops with a wire.

But wires actually create magnetic fields. And that means the inductor behaves in an interesting way and can do interesting stuff.

A simple homemade inductor