Big Joule Theif

[Lidmotor]

Automatic Solar Joule Thief

@Slayer----This one should be an inspiation to everyone struggling to get this Joule Thief circuit to work. I finally got it to self- run on solar energy AUTOMATICALLY!!! Thank you --- and all the other people who keep the interest alive with this simple little circuit.
The next step for me is to make the BIG joule thief run like this one does.

YouTube - Automatic solar Joule Thief



Lidmotor

[Bodkins]

Hi Lidmotor and everyone

lid can you do a upload of the setup from the solar thief would like to have a go? its so small on utube


also EVERYONE

Im doing a day at my little girls school talking about magnets, sparks and lights, but I was thinking of getting the kids to building a JT to take home.
Teach them young!!!
So I need your help for a very simple setup that the kids can do with charging!
So when the kids take it home the parents start thinking!!!!!
WHAT THIS A LIGHT THAT CHARGES A BATTERY TOO!!!

Take Care ALL
Bx

[Lidmotor]

Automatic Solar Joule Thief

Hi all,
Here is a simple drawing of the "Automatic Solar Joule Thief" circuit. It turns the JT circuit off when the sun is charging the battery and when the ambient light gets dim it turns the circuit back on.
@Bodkins---The JT part of this can be run independant of the solar part and you can see how simple it is. I have used all kinds of (2) winding inductors and a regular 1:1 transformer works fine. The standard design is two 20 turn wraps of about 26 ga on a ferrite toroid. It is not really that critical but regular iron or steel for the core doesn't work well at all. The resistor on the "B" winding usually goes right before the base of the transistor in the regular circuit. You know me---I like to mess things up a bunch and see if it still runs.

Here is a video of the thing with a supercapacitor setup. It was just for demostration. Normally you use NiMh rechargable batteries or even just alkaline.

YouTube - Solar Joule Thief Runs A Fan

Cheers,
Lidmotor

P.S.---Circuit update! Today I moved the connection of A1 on the JT side around the 100 ohm resistor straight to the emitter of the 2nd 2n2222 so it gets more juice. This gives more light and the JT still turns on and off like it should.

[Bodkins]

Thanks Lid
Tectalabyss

[Guruji]

Hi Zigis and Xenomorph thanks for help. I rewinded the 20turn part with thicker awg wire. Now the thing is that I had to do another layer for 20turns don't know if this is good
When I tested the joule thief only with a green led it lit with two 1.5vbatts. I tried it with one nothing came. Earth has to be on the 2n2222 no one told me about this Ok ok at least something is coming now.
The CFL still not lighting up.
Thanks guys

Guruji, maybe for testing start with larger voltage, say 9v battery.
If you have neon, solder it between collector and emitter, like in Bedini SG, this is good for transistor protection without load too. If BJT work without load, neon must light. If you have no neon, you can put LED here too.

If you turn on with 9V battery and without anything in output, and neon light - BJT work. If not light, try to change ONE 20 turn coil polarity, only one coil, triger coil only or output coil only.

Once you get neon working, you can start to experiment more with voltages, output etc.
Zigis.

@Guruji:
In case you have shorts between the layers of your secondary winding, then the induced voltage will be much less and thereby inhibit the coil singing volume.
Have you put a diode between collector and emitter of the transistor just to check if the Joule Thief part actually works? It looks like you don`t get an oscillation going.

As Slayer007 has pointed out multiple times, check the correct wiring of your primary winding. Look for the dot indicators in the circuit diagram.
Try to reconnect the wires differently, you just have 4 possibilities to actually connect the ends, try them all and see if it works then.

Or connect a small neon signal lamp to the ends of the secondary winding. With 480 turns, the induced voltage should be high enough to reach the firing voltage of the neon at least.


If neither LED nor neon will light then check your circuit. Measure your transistor voltages/current, if you can`t do that use another transistor.
Check if you haven´t mixed up collector and emitter. The transistor is the main part of the oscillator.

Good luck

[shlodo]

The Joule Thief is perfect for a 'School Girl' project!

Hi Lidmotor and everyone
lid can you do a upload of the setup from the solar thief would like to have a go? its so small on utube
also EVERYONE
Im doing a day at my little girls school talking about magnets, sparks and lights, but I was thinking of getting the kids to building a JT to take home.
Teach them young!!!
So I need your help for a very simple setup that the kids can do with charging!
So when the kids take it home the parents start thinking!!!!!
WHAT THIS A LIGHT THAT CHARGES A BATTERY TOO!!!
Take Care ALL
Bx

@Bodkins - I like your idea, it's great to get kid's into this stuff. And it will be a fun project. Here's some simple designs. Ive uploaded a simple circuit too






-shlodo

[shlodo]

Hi Zigis and Xenomorph thanks for help. I rewinded the 20turn part with thicker awg wire. Now the thing is that I had to do another layer for 20turns don't know if this is good
When I tested the joule thief only with a green led it lit with two 1.5vbatts. I tried it with one nothing came. Earth has to be on the 2n2222 no one told me about this Ok ok at least something is coming now.
The CFL still not lighting up.
Thanks guys

20 turns should be fine. CFLs dont work very well. try a Fluoro tube and run it at 3V. Also use 2n3055 not 2n2222.
u should be able to get a neon to light on the primary part of the JT. and a Fluoro off the secondary
-shlodo

[Guruji]

20 turns should be fine. CFLs dont work very well. try a Fluoro tube and run it at 3V. Also use 2n3055 not 2n2222.
u should be able to get a neon to light on the primary part of the JT. and a Fluoro off the secondary
-shlodo

Hi Shlodo I tried a 2n3055 as a joule thief circuit only but did not light the neon.
Did you mean that I should hook the two transistors for this to work?
Thanks

[Guruji]

Joule thief

Thanks Tectalabyss for your encouragement.
On my last attempt I used slayer big joule thief but did one transistor only 2n3055 instead of 2n2222 on the 20turn coils and put a neon between collector and emitter as Shlodo told me.
Earth to emitter.
Did I do something wrong? I just checked joule thief part.
Thanks

hello guruji.
Could you send a drawing of your circuit so we could see if maybe something was not right.I dont have the 2" torroid yet so I'll have to wait till I can be of more help.Dont give up! Tec

[Guruji]

Big Joule thief

Yeeeeeeeeeeeesss I did another one with a small torroid but this one working atleast
On the big one there's something wrong with the winding atleast now I know.

Thanks guys

[Brownsville]

Lidmotor Halo Light reproduction

I have been working on the Halo Light. I now have the inverted joule theif part working with the 2" coil and lighting a 30 watt round fl. Lidmotor has been a great help and source for getting this going and I am looking forward to getting it done.

I am not getting the light output that I am looking for at the moment but at least it is lighting the light. Also do not have led lit yet. I think I need a resistor from the B coil to the base.

I used 24 gage wire with the Slayer007 20 wrap bifilar and then 450 plus wraps on the pickup. I used 2 sided carpet tape between layers and on the coil before starting. 100 total feet of wire.....very tedious work.

Thanks for the inspiration guys

Brownsville

[Xenomorph]

Ferrite cores can differ enormously since different materials can have been used (Barium,Strontium) and different FeO2 percentages.
I have wound a couple of identical winding counts onto different ferrite cores and got varying results.

[Guruji]

Glad to hear you got the smaller one working Guruji.
I still havent gotten my 2" coil yet . Have you tryed to unwind the High output part of your coil ? It sounds to me like it has shorted while you were wraping if you cant get an output. Just a thought I've been busy this is the first chance I've had to get a reply in.Dont give up Tec

Hi Tec yes I already unwind the coil now. I tested the joule thief and it works.
Now I am winding the long coil. I have to joint the coil and I am very aware now not to short the coil. It's good that it's not a whole coil in a way I am testing it before joining it. It's giving bigger voltage when testing on the secondary everytime I join it .
Thanks guys.

[Watson]

My first post here. I've built a lotta Joule Thiefs, mostly running off 1.5V or less, and mostly for driving LEDs. Some were for V boost, like running a 9V radio off a 1.5V cell.

I'm surprised that a 2N3055 can light up a neon, since the transistor's collector breakdown voltage is 60V and it takes 90V to light the neon. The circuit really needs a 2SC2625 or similar, with a BV of 400V. I get them out of old PC power supplies that got replaced because the fans was noisy. The other parts in there, such as toroid and coils, are good for JTs and such.

i'm also surprised that so many parts are blown out doing these experiments. Some simple protection diodes should prevent that from happening. But when a circuit is running at several tens of kHz, using a 1N4007 diode is not a good idea. Its reverse recovery time is too slow, and may act more like a capacitor than a diode. It's best to use a fast recovery diode, also scroungable from the PC power supply.

Best of success.

[Watson]

Attached is one of my recent creations, an air core JT, running an aqua LED. This is a 'conventional JT', nothing but a resistor. Later I'll post a supercharged JT.