Big Joule Theif

[StevanC]

newbie and aircored

anyone tried the joule thief without the iron core?

I was all sceptic but went wow and now go mostly aircored...

[sucahyo]

Right now I only have one torid with a secondary coil on it.
But adding the second one to the base still speeds it up and still gives you more power.
When I get another biger toroid I'll be doing it like in the circuit drawing.

Interesting setup, faster but more BEMF at the same time. You should get higher frequency too if you replace the resistor with 10K ohm, but BEMF may reduce.

[seth]

Love your work slayer! Great videos, and cheers for the latest circuit. I'll try replicating this Big joule thief next. I've just got 2 little ones lighting bundles of LEDs at the moment, but I wanna go large....and you seem to have had a lot of success

[slayer007]

Heres a joule thief with two toroids going to the same transistor.
This way it seems to run twice as fast with both coils triggering the transistor base.

The joule thief is around 20 turns and the secondary coil is around 100 turns.

Right now I only have one torid with a secondary coil on it.
But adding the second one to the base still speeds it up and still gives you more power.
When I get another biger toroid I'll be doing it like in the circuit drawing.

[sucahyo]

Why not just use prefab darlington pair transistors?

The one I suggest is not darlington configuration. I attach the picture.

I don't which one is better though. It said darlington configuration reduce the frequency.

[redeagle]

Why not just use prefab darlington pair transistors? Another thing that the paired transistors do i help to keep your coil from short circuiting. i confirmed this when i had one good and one bad on my bedini circuit fan motor. the bipolar rotor locked down once it stopped but i would still sustain rotation. I've heard that this is a big use in large motor controllers so you can limp along for a little while.

Matt

[sucahyo]

I see, thanks.

[slayer007]

I don't have Bedini SSG, I only have joule thief.

At 12V 0.25 Amp input, it charge 12V battery at 0.11Amp. When the charge battery removed, the input current reduce to 0.22 Amp. I guess 0.22Amp is consumed for powering the coil and heating it. Should be more efficient at higher Amp (longer coil and reduced coil resistance) Joule thief using Toshiba 2N3055.

Edit:
Anyone ever parallel additional transistor? It draw more current but the BEMF also increase too. Just playing with two TIP2955, single = 0.23A, double = 0.27A. I don't monitor the BEMF amp, but I use it to drive an ordinary computer fan. The fan speed is higher when I use double.

What I mean by parallel is two transistor or more joined together, collector is binded together, emittor is binded together, base is binded together.

Here is what I mean:
Max BEMX is not at max input current draw

Yes I'v done the same with the pulse generator I was working on.
It was like the more transistors added the less power it used and the more it would put out.

If your transistors get hot this is allso a good way to cool them off a bit.
Adding more transistors splits the power between them so theres not so much power going into just one.

[sucahyo]

Has anyone been able to test the joule thief against the bedini style solid state oscillator for a comparison between input and putput current?

Matt

I don't have Bedini SSG, I only have joule thief.

At 12V 0.25 Amp input, it charge 12V battery at 0.11Amp. When the charge battery removed, the input current reduce to 0.22 Amp. I guess 0.22Amp is consumed for powering the coil and heating it. Should be more efficient at higher Amp (longer coil and reduced coil resistance) Joule thief using Toshiba 2N3055.

Edit:
Anyone ever parallel additional transistor? It draw more current but the BEMF also increase too. Just playing with two TIP2955, single = 0.23A, double = 0.27A. I don't monitor the BEMF amp, but I use it to drive an ordinary computer fan. The fan speed is higher when I use double.

What I mean by parallel is two transistor or more joined together, collector is binded together, emittor is binded together, base is binded together.

Here is what I mean:
Max BEMX is not at max input current draw

[redeagle]

Has anyone been able to test the joule thief against the bedini style solid state oscillator for a comparison between input and putput current?

Matt

[slayer007]

Here is a video of a small joule thief with a secondary coil winding.
The second coil puts out about 8 volts and can fill a large 4400 mfd capacitor to over 75v in about 10 minutes.

It will allso charge 10AA rechargable all at once just on the second coil.

This is running off a rechargable 1.2v AA battery that has 1.28v in it.
It took about 10 minutes to recharge 10 AA batterys from 8.9v to 13v.

YouTube - Joule Thief With Secondary Coil Winding


EDIT.

I let it run for about an hour longer to see how high it would go up to.
The charge batters went up to 13.22 and the run battery went down to 1.26
Then after letting set for two hours the charge batters settled to 12.50 and the run battery went back up to 1.28 where it started.

[sucahyo]

battery charging

Hers a link to how to wind a Moebius coil.
I'd like to use this in my next JT and try wraping some thin magnet wire around the outside of it and see what I can pick up.

Actually, mine is a lot more primitive. I wound the bifilar over it self in 45 degree angle after one loop.


@all, I use 1 Amp transformer for my 12V joule thief.

I wonder which one is more effective for charging battery. PNP or NPN?

[Lidmotor]

Lazy Joule Thief

I found that small switching diodes and zener diodes (only tried 12v zener so far) work in place of the 1k resistor.
They gave me different results, but the LED lit up brighter. I still can't get that stupid toroid to work though.

Matt---I made a joule thief yesterday that didn't work. At least it didn't want to work. I finally poked at it enough and it finally did it's job but not well. I tried a standard 1/4 X 20 lock nut as the core and wrapped about 40 turns of twisted wire on it just to see if that would work. It just sat there. I thought that it might be my other circuit components so I swapped out the coil with my big trifilar that I used in the 'Big Joule Thief'. Everything was ok and the circuit ran fine. Soooo-- I got mad. The thing should have worked if the theory about WHY it works was correct. I started trying different transistors, resistors and LEDs----the shot gun approach. Just fire a bunch of stuff at it and force it to work!! It finally did but the amp draw was higher than if should be and I fried two transistors. I really don't know why it started working. Sucahyo's ideas are good ones about what to do to get it running. In my case I think that twisting the wires was a mistake and the iron core needed to pickup some kind of field before it would start up. Also I was using clip leads on the long ends of the coil wire. You are right I think that the coil leads should be short and firmly attached somehow. If all else fails, just build another one. About 30% of what I build never works.

[ApEkV2]

I found that small switching diodes and zener diodes (only tried 12v zener so far) work in place of the 1k resistor.
They gave me different results, but the LED lit up brighter. I still can't get that stupid toroid to work though.

Here is my video showing that a zener diode works in place of the resistor.

YouTube - Joule thief #1

[slayer007]

Is this a 'correct' joule thief circuit? It burns up potentiometers after running a couple of seconds, and coil starts screaming.

Yes its just a basic joule thief circuit.
But you need a big coil to run it with 12v or your transistor will fry.

You could allso try it without the pot.
I dont use one in mine,but it is nice to controll the voltage.