Introduction: Joule Thief for Me

About: DIY my way through life. For me, Instructales is a way of living. It's my making log. My life is counted with the instructables I make. Visit my website and If you need more Arduino Mentoring for your class yo…

Finally , I made it !!!

I wanted to make this nice circuit as soon as I heard of it.

If you don't know it , it's OK.

Read about it : Joule Thief

Simply , it's a simple boost converter. DC voltage step up circuit.

I used this instructable as a guide. By 1up

Special Thanks to my beloved wife Sara for crafting the Joule Thief beautiful logo.

When I found this circuit I really wanted so much to make it.

It has been around from about 1999 . So it's not new and you can find many other tutorials and instructables showing you how to make a Joule Thief .

But in this instructable I will show you my experience and what pitfalls I got in so you can avoid when you make your own circuit.

You may also want to try this ready made kit and assemble it. You can get it from Amazon or eBay for good price.

Let's get started.

Here is my Channel on Youtube:


Step 1: Components

I didn't buy anything for this circuit.

I had all the components in hand. And so would you, I guess.

Some components were separate and some were removed from old stuff.

1k Ohm Resistor from amazon DE or ebay or Banggood or Aliexpress

2N2222A Transistor from amazon DE or ebay or Banggood or Aliexpress

Toroid ( to be explained in details ) from amazon DE or ebay or Banggood or Aliexpress

LED ( better to be white - to test your circuit is working ) from amazon DE or ebay or Banggood or Aliexpress

AA Battery ( Better use an old battery ). from amazon DE or ebay or Banggood or Aliexpress

Some wires.

Some crocodile clips from. amazon DE or ebay or Banggood or Aliexpress

Step 2: Details

You can get components from old circuits or devices.

I got LED and transistor from old electronic scrap.

I got the toroid core from an old CFL Lamp.

The toroid in the CFL or PC power supply unit is wound in a different way than we want it here.

So I just got the ferrite core from the toroid and wound it myself.

I got the wire for winding the toroid from an old damaged transformer I got from scrap.

I would like to have two pieces of copper wire of different color each.

The different colors can help you in winding the toroid. But I only had a scrap copper wire with one color which made the process of winding the toroid harder but it went good anyway.

Tip :

The toroid has to be wound with at least 8 turns . Note that each couple of wires are count as a turn.

First I had a thick wire with the same ferrite core and it could be wound in 4 turns couples , so it didn't work.

When I wound it in 8 turns in couples with the thin wire it worked.

I found this one sold on eBay.

Step 3: Circuit

You can make any one of the two circuits. They are the same.

The two circuits are valid and working . I 've tried them both and working fine.

Just assemble the circuit as shown.

Tip :

Note carefully the Dot Notation. The toroid has two coils , the point at which the two coils are connected together to the battery must be connected with two different ends of the coils to comply with the Dot Notation.

Step 4: Test the Circuit

That's it. Just connect the AA battery and see the magic.

White LED and Blue LED can be illuminated with only one AA old battery.

Without the Joule Thief circuit, the White and Blue LED needs at least two new AA batteries ( 3 Volts ).

Thank you for reading my instructable.

You can also find my book Learn By Making on Amazon website.

1. Leave comments stating your point of view about this article.

2. Buy our book on Amazon Learn By Making.

Thank you for visiting our instructable.

Here are some of my latest books on Amazon.

Learn By Making

Backyard Wind Turbines

Epilog Challenge VI

Participated in the
Epilog Challenge VI

Battery Powered Contest

Participated in the
Battery Powered Contest