Joule Thief

[Pirate88179]

@ freepow:

As Gary has said, a lot of this depends on your toroid...permeability, size, material, etc.  Try replicating one of the many designs posted both here, and on our diagrams topic, that are proven to work.  Then, go from there to hopefully, improve them.

There are folks here getting over 1,500 vac from hand wound JT circuits so you, if you do everything they did and use the same materials, should be able to do that too.

I always recommend replication to get started and then, by all means, experimentation.

Bill

[jeanna]

Thanks, but with my winding, all that happens is a bright led light ok on the secondary, but if i connect the led to the bifilar and emitter, it light very bright,  it seems that the secondary is not out putting much AC at all

freepow,
Are you removing the bifilar led?
We call that one the Basic Joule Thief Light, or BJTL. So, Did you remove the BJTL?
That will help the light from the pickup.
One important thing to remember is that this BJTL is the thief. It takes all the juice from the battery.

If you use just the pickup, the amps draw from the battery will go down, and you will be able to keep a battery going longer.

i'm not having much luck with any high AC no matter what winding i am doing, whats going wrong ?
I have tied that blue bifilar winding with 20 wraps originally-got around 113v i think, then decreased it each time and the volts also went down,

Perhaps you have what is called a 'high permeability' toroid. They need a lot of turns to get their effect here and I do not believe they are any good for this purpose.

Sometimes it is hard to get started.
Sometimes you need more turns on the collector, but then with some toroids you need more on the base.
I would say go back to the 20T bifilar.
Let me ask is it 20 total? so it is 10T,10T = that is how we write it symbolically in our group.
I am assuming you have it 10T,10T. So, put that back as you had it. Now, take away one at a time from the coil that is connected to the base resistor.

See how that goes. Then you can try it the other way.

Another important piece, and this may be all it is. You must use one of those super bright leds.
The reason is that they are painted with fluorescent paint, just like the inside of the fluorotubes. (this is done to change the color from blue to white) Now, this makes your superbright a tiny fluorescent bulb. The light is very bright but has a different quality when it is using high frequency high voltage and not watts.
You aren't there yet, but you must get a superbright to continue.

Well, you can continue with the red, but it is an ordinary led without any phosphorescence and you will not get the same effect with it ever.

OK?

Keep going.

I hope you can find some super bright leds to use.
I also hope you can find a good source for toroids.

BTW, if your toroid was used inside a 240v CFL, it may not have the right properties to do the job from a 1.2v battery. It was in a device that was meant to have 240v input, and it only needed to create a boost of 150 to 200volts. You must boost from 1.2v. And that is a big difference..


jeanna

[freepow]

Hi again, thanks everone for your response, its great to talk to people with same interests !
Well this toroid that i'm using on this circuit now is a 1.5 inch diameter ferrite bought from jaycar electronic in Aust, and hand wound with 2 wires, each wire of 20 turns together (bifilar),
I have one 14-16,000 mcd LED, it light very brightly with DC on this toroid at about 113v, when I connect double volts = 3v, I get about 240-256v on multi-meter, so I went down to 4 turns with 2 wires, that = about 30-40v, then I wound on opposite side about 60 turns single wire, and when I use that 60 turn secondary for my 14-16,000 mcd LED, it lights just ok, dont know whats going wrong, cant be much AC-V
in that 60t, else it would be bright, so, dont honestly know whats wrong.
I'm trying some experiments, so I can light up each room in the house, without using the mains power, ideally i'd like to use 1-aa JT with super bright LED - several in each room... OR ... 1-aa JT with a 15 watt fluoro in each room etc.
But the only thing i cannot seem to get past - is getting decent high volts of AC !

[freepow]

Almost forgot to say...that i did take led off bifilar and put it on secondary 60t side, thats what i did and led lit just ok, but only on bifilar it very bright !

[resonanceman]

Almost forgot to say...that i did take led off bifilar and put it on secondary 60t side, thats what i did and led lit just ok, but only on bifilar it very bright !

Freepow


I am guessing you may be running  into power limit  problems .
The 2222s and 3904s  just don;t  have alot of power .
You  are using  a fairly  large  toroid .  Didn't you say  you had a  toroid  out of  a  CFL?
The  little toroid might work  better with the  small  transistors   you have.


From  my  own  experience   it seems like  if you try to use a secondary  with to many turns  it  bogs down the  whole JT

Do   you have any  space free on the   toroid ?
If  so you might  try a small  secondary  .......5 or 10  wraps and see what happens .

If  the  smaller  secondary  works .... there is  a very good chance that the  larger  secondary  will work  with a bigger transitor .......like the  2N3055

gary