The Transistor as a Switch: A Practical Guide for Beginners

Using the transistor as a switch is a practical and useful skill to have. By setting up transistors in very simple circuits, you can easily control things like DC motors, lamps, buzzers, and much more. This is useful for beginners and experienced electronics enthusiasts alike. In this guide, you’ll learn the basics, the necessary components,

Bipolar Junction Transistor – A Getting Started Guide for Beginners

The Bipolar Junction Transistor (BJT) is one of the two most used types of transistors. You can use it to create audio amplifiers, switch on/off DC lamps, motors, and much more.

In this tutorial aimed at beginners, you’ll learn the basics you need to start having fun and design your own transistor circuits.

Bipolar junction transistors on a circuit board

The Insulated Gate Bipolar Transistor (IGBT): A Practical Guide

This is a practical guide to the Insulated Gate Bipolar Transistor, or IGBT. You’ll learn how to use it from a practical standpoint – without going into the physics of what it looks like on the inside. The IGBT is often presented as something complex and advanced. But when you strip away the physics explanation and get down to practice, putting it into a circuit is straightforward.

By the end of this guide, you will be able to use an IGBT and build your first simple circuit with it.

IGBT symbol and package

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

MOSFET Gate Resistor

Do you need a MOSFET gate resistor? What value should it be? And should it go before or after the pulldown resistor?

If you’re a bit impatient and just want the answer, here it is:

It will most likely work without a gate resistor, but adding one can prevent some potential problems. And 1000 Ω will most likely work. See the circuit diagram below for connecting your MOSFET gate resistor (the Pull-down resistor is optional):

Mosfet gate resistor placement

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.

What Is an H-Bridge?

An H-bridge is a simple circuit that lets you control a DC motor to go backward or forward.

You normally use it with a microcontroller, such as an Arduino, to control motors.

When you can control two motors to go either forward or backward – you can build yourself a robot!

H-bridge prototype on breadboard

How Astable Multivibrator Circuits Work

Astable multivibrator drawing

The astable multivibrator circuit is a classic circuit for flashing two LEDs. It doesn’t have to flash two LEDs though. It can blink just one LED. Or it can create a tone to play on a speaker.

First, let me show you the circuit in action:

Want to know the theory behind how the circuit works?

There have been many attempts to explain this circuit. Most have failed to explain it to other than those already beyond the beginner level.

So here’s my humble attempt.

PNP Transistor – How Does It Work?

The PNP transistor was a mystery to me for a long time. But when I at some point was forced to learn it, I realized that it was pretty simple. And if you want to design circuits with transistors, it’s really worth knowing about this type of transistor.

For example, want to automatically turn on a light when it gets dark? The PNP transistor will make this easy for you. Let’s dive in!

PNP transistor and symbol

In my article how transistors work, I explained how a standard NPN transistor works. If you haven’t already, I’d really urge you to read that article first.

If you understand the NPN transistor, it will make it easier to understand the PNP transistor. They work pretty much in the same way, with one major difference: The currents in the PNP transistor flow in the opposite directions of the currents in the NPN transistor.