Use LEDs With Only One AA Battery! - Super Simple Joule Thief

What Is A Joule Thief ?

A joule thief is a minimalist self-oscillating voltage booster that is small, low-cost, and easy to build, typically used for driving small loads. 

It can use nearly all of the energy in a single-cell electric battery, even far below the voltage where other circuits consider the battery fully discharged (or "dead"); hence the name, which suggests the notion that the circuit is stealing energy 

The circuit is a variant of the blocking oscillator that forms an unregulated voltage boost converter. The output voltage is increased at the expense of higher current draw on the input, but the integrated (average) current of the output is lowered and brightness of a luminescence decreased.

How is this Joule Thief different?

Unlike most other joule thief circuits, this circuit uses a standard inductor. Hence there is no need to salvage a toroid and wind wire away to glory.

The circuit is super simple, can easily be assembled on a breadboard, or can be soldered onto really tiny PCBs, if you want...

For simplicity and beauty, I made PCB for it

As the circuit is very simple, materials are easy to get. There is no need to salvage components from old stuff, unlike in the case of using a toroid.

• LED X 6
• NPN Transistors （S9013） X 1
• 1k Ohm Resistor x 1
• Inductor - Anything between 100uH and 510uH (I used 100uH & 330uH ) X 2
• PCB
• AA battery - or any battery giving less than 1.5volts
• Jumper wires

My idea is use 3 pcs of PCBs to make the joule thief look like a battery

Due to my fault, the size of PCB version 1 is too small, and the VCC and GND positions are reversed. I have to redraw the PCB , PCB version 2 will be upload later

I use EasyEDA to design PCB and upload the design to JLCPCB.com to manufacture PCB.

JLCPCB make high quality prototyping PCBs for people all over the world. They have over 300,000 worldwide customers with over 8000 orders per day! They have over 10 years of manufacturing experience and are super reliable. Try it for your self and get 10 PCBs for just $2 at JLCPCB, New registered users US$54 offer , Order here

You can use my gerber files to ordel your own PCBs, and build this DIY Project.

Just a quick example how to order PCB from JLCPCB.com:

1)press "QUOTE NOW"

2)press "Add your gerber files"

3)upload zip or rar

4)all properties could be left default

*the only thing You should change from properties is PCB Color

gerber files

Version 1

• Size too small
• VCC and GND positions are reversed

https://github.com/James-workshop/Joule-Thief

version 2

https://github.com/James-workshop/Joule-Thief

just are soldered according to the Schematic, they can be used, no ​need programming and debugging