Joule Thief - use LEDs with only one AA battery!

 Making LED devices portable can be a little bulky due to the batteries. The Joule Thief solves that, by boosting a single AA battery's voltage to a high enough level to light a LED.

This ible will entail how to solder a joule thief together from www.thejoulethief.com. They cost $7 each.

The kit from thejoulethief is interesting in the fact that it deviates from the standard bulky joule thief design to a small and compact pcb layout with a few extra components for efficiency.

Step 1 Open Source

Attached are the Eagle schematic and board files. 

Comments

[markb710]

I'm not sure what program to use to open 2 Eagle schematic & board files. Can you please advise? Thanks Mark

[Vator]

0.001 µF = 100 nF ?

[rfmonaco]

0.001 uf = 1 nf = 1000 pf

http://www.justradios.com/uFnFpF.html

[geeklord]

Finally! A kit! I could never get the toroid version to work. Just got little flashes.... Anywho, Ill have to get one of these.

[highhacker]

I have wound Hundreds of torrois Jts hers one that will power a CFl blub or 500 christmas tree bulbs from just one 1.5 volt battery for 5 days straight !

[shanakoenig]

Can you please post a schematic of this circuit?

[pben]

I found a IC based boost regulator at Pololu that I liked. http://www.pololu.com/catalog/product/796 The circuit on this page uses 2N2222 which I haven't seen before. That will cause a loss in efficiency but should be a lot easier to find than the transistors of the classic Joule Thief.

[mugiwara]

what inductance value is it?

[microman171]

Unless you are 'Big Clive'  I don't think you have permission to call the the 'joule thief'.  Big Clive was the one who coined this name.  Before he called it the 'joule thief' he called it the 'vampire torch'.

If you are Big Clive, thanks for designing such a nice kit!

Otherwise, please don't take names from other people's projects.

[shams]

Sorry dude BIG clive didnt patent joule thife.......so we all can make and use it...thatz why inventor like big .c publishes this invention in public

[highhacker]

It was patented In 2010 and the circuit described is not a Joule thief but a boost converted used in many solar garden lights . a REAL joule thief uses Ferrite bifialar transformer and ONE transistor and current draw is less than 1 milliamp on a silicon transistor of a volt of .725 . germanium Jt's can run as low as .2 volts and in the MICRO amp range while lighting up several Bright White Leds .

[acmefixer]

Wow, that was a confusing answer. The values given are way off the mark. I think you should go to Wikipedia and read up on this subject before you give numbers off the top of your head.

[highhacker]

Screw Wiki's there not the facts son . I am one of the inventors of the lowest powered light device in the world and have been very educated for over 40+ years in Electronics so i know .

[acmefixer]

Okay, maybe I should be a little more blunt and say that the numbers you gave don't make sense.

Back to the schematic. As it is shown, the circuit won't oscillate. I believe the mistake is the capacitor C1 is connected to the emitter of Q2 and ground, but instead it should be connected to the collector of Q2.

Well, Obi Wan, if you know so much about electronics, how come you didn't catch that mistake?

[highhacker]

Because this is not My schematic nor a joule thief . That was my point . I have no idea who this person is who posted this "joule thief project " but as i had said this is not a joule thief and yes it works but it is a boost converter thats all man . IF yo want to see real work visit overunity dot com and see the jule thief thread . thanks .

[jomac_uk]

So in the same vein, the people who invented the transistor, and the IC etc are the only ones allowed to use the name?

Just a point to ponder for the non pedantic of us out there

[RazorConcepts]

Sorry I did not know, but the Joule Thief may have been coined by Big Clive, but it seems like Evil Mad Scientist popularized it (with no mention of Big Clive).
http://www.evilmadscientist.com/article.php/joulethief 

[westfw]

The EMSL does refer to Big Clive as "the original site"
http://www.evilmadscientist.com/article.php?story=joulethief
Clive credits "Z. Kaparnik" in EPE magazine.  I suspect the origin lies even further away...  I don't think that anyone has trademarked the name...

This seems to be a different circuit, though (two transistors, single-winding inductor.)  Probably like  http://www.joulethief.com/kit.php or this one published (with lots of explanation) in Electronics Design http://electronicdesign.com/Articles/Index.cfm?ArticleID=5886

[RazorConcepts]

Can anyone reach Big Clive's web site about the joule thief? It doesn't work for me.
www.emanator.demon.co.uk/bigclive/joule.htm

[microman171]

http://www.bigclive.com/joule.htm

"In the November 1999 issue of EPE (Everyday Practical Electronics), a small and intriguing circuit was published in the Ingenuity Unlimited section by Z. Kaparnik. It was a very small implementation of a typical transformer feedback single transistor invertor. The transformer was a standard ferrite bead with two windings wound on it and the circuit was using the high voltage pulse generated when the transistor turns off to light an LED from a single 1.5V battery."

So it looks like it was way back in 1999 or earlier that this was invented.  The point I was trying to make is the kit name. 

Seeing as you have released all of the schematics for free, things are different.  You have every right to make and sell kits and boards.  Just make sure you put a link on your website for what a joule thief is (or rename it...).  Your circuit is actually different, so call it what you like!

[highhacker]

Actually the Circuit is a solar lightBoost oscillator circuit and not a joule thief ! and YEs Big Clives DID INVENT joule Thief . As the Name implys and Further more the Blocking oscillator was not invented transistorized until 1988 and the led was not invented until 1962 and available in red only . The actual product has many variations and we explored all of them from 2008 to 2011 . the Patent is issued in 2010 for Joule Thief whick used the ferrite transformer toroid and one transistor . We have versions that operate 1000+ white leds from less that 1 milliamp at 0.765 volts so what you are showing is an energy hog not a real joule thief that actually can do work . For more info and public Domain Circuits pertataining to modifications to a blocking oscillator invertor see overunity Dot Com and jule thief thread .

[acmefixer]

Here is a picture of a JT circuit from 1970. It wasn't invented by Big Clive. I think it would be helpful to all if you didn't give misinformation.

http://watsonseblog.blogspot.com/2011/01/2011-jan-12-joule-thief-from-1970.html

[highhacker]

Again you are wrong . Joule Thief was coined by Big Clives . Also the circuit you posted does not run off a dead AA battery and requires +27 volts . This is a very old energy hog led blinker oscillator . DA

[acmefixer]

The term Joule Thief was recently given to this circuit, but the semiconductor version of the circuit has been around for decades, and long before that as a "Hollow State" (vacuum tube) version. It's a blocking oscillator.

[westfw]

What makes it a "Joule thief", rather than just an interesting oscillator, is the ability to do useful work from a battery that is otherwise "dead" (eg 1V or less from a 1.5V alkaline cell.) It's not just the circuit, but the whole assemblage of "dead battery, simple electronics, white LED" emitting somewhat useful amounts of illumination, that is "stealing" energy that would otherwise be thrown away...

I'm pretty sure there was never a vacuum tube circuit for emitting light from a single discarded dry cell :-)

[highhacker]

You are 100% correct ! this circuit as we know as Joule Thief or some call it a blocking oscillator inverter was recently invented in just the last 10 years . Also the Availability of Leds in Various Colors was also the last decade . So it is a new and very interesting circuit never explored before to power lights from less that 1 volt with only one transistor .

[acmefixer]

Here is a picture of a JT circuit from 1970. It wasn't invented by Big Clive. I think it would be helpful to all if you didn't give misinformation.

http://watsonseblog.blogspot.com/2011/01/2011-jan-12-joule-thief-from-1970.html

[RazorConcepts]

This link:
www.emanator.demon.co.uk/bigclive/joule.htm

[pedrotome]

I'm kind of an Eagle noob... How do you create/choose the "thing that goes on the Board design part" for vertical mounted resistors? Whenever I choose a resistor, it's always for horizontal mounting... Also, do you use a simplified library with only the most common components? If so, would you mind sharing it?, cause Eagle has lots of libraries and each library has lots of variations for the same component. For example, whenever I search for a resistor I'm like "HOLY -blam!- THERE'S SO MANY, WHICH ONE DO I CHOOSE!!?" and it just drives me mad... :p Finally, if I wanted to make this circuit to be able to power anything, would I just need to do this (see pic)? Also, is the input voltage/current irrelevant? The circuit will just boost whatever is inputed? Thanks! :)

[yourdiyguy]

what is the v output of this device?

[RazorConcepts]

I'm not sure about peak voltage, but putting a 10uF cap on the output yields a roughly 2.1v  output. 

[yourdiyguy]

cool. I bought 4 so I could use them in some projects, also so I would not have to go through the trouble of getting all the bits and pieces. very excited!

[Bongmaster]

any chance of all the component values? ;)

like wat the transistors are and wat kind of inductor :)

[RazorConcepts]

I will post the schematics that will depict the values.
2x transistors are NPN 2222s, 3904s should work also.
I think the inductor is a 470uh, but anything from like 200-500 should work with varying efficiency.

[Bongmaster]

kool components that i actually have XD

[TheWelfareWarrior]

BAH! I don't understand how the inductor works! WHYYYY!?!

(could someone post a link to something describing it?)

[RazorConcepts]

http://www.talkingelectronics.com/projects/Inductor/Inductor-1.html 

[TheWelfareWarrior]

404'd, and I understand how an inductor works, I guess I don't understand the way the circutry works together...

Isn't the idea of a joule theif to transform the low voltage of an almost dead battery into a slightly higher, more usable voltage?

[RazorConcepts]

Yup, that is what it does. See my response to atombomb1945

[atombomb1945]

So, the second transistor and the inductor would be what replaces the toroid?  Having very little knowledge of this, I am guessing that the inductor and the capacitor helps create the pulse that has the transistor drive the LED on low voltages.  (If I am wrong, please let me know as this site is for instruction)

Does anyone have a circuit diagram on this?