A beginner's Guide to Driving LEDs - Part 3

 
Actively Stabilizing the Current
In part 2 of this tutorial we found that there are situations, when a simple resistor is not good enough to keep the current through an LED stable. There are countless ways to stabilise the electrical current actively. Some are simple, some are complicated. I will show a few here.

A Beginner's Guide to Driving LEDs - Part 2

 
Resistance is not futile...

Part 1 of this tutorial showed why using an LED is not as straight forward as using a light bulb. Now we have a look at different ways to operate an LED.
 
The simplest and well known way to operate an LED is to add a series resistor. It is quite easy to determine the value for this resistor:

A Beginner's Guide to Driving LEDs - Part 1

Introduction

LEDs are just great. Nowadays they are cheap, durable and power efficient. You get them in all colours, shapes and sizes.

But along with all the advantages comes a disadvantage, too. LEDs have special demands when it comes to their power supply. In most cases, this is not too bad. But many beginners in electronics have problems to understand those requirements. With this post I would like to help those people to get an intuitive understanding of how to use LEDs. I will keep it simple, but hopefully still useful.