Joule Thief

[jeanna]

Hey thanks for the images about coils.. I see that it is a second coil on the same ferrite..

But what does the secondary coil do? Why add a second coil?

Well now dog812, that is the sweetest story around, these days.

Once you remove the led from the jt position, and instead touch it with the secondary leads, it will light as bright, sometimes brighter than in it's jt place. Then, you can put as many as you own in parallel with it and they will all light up really bright. The amazing thing is the amp draw will stay the same or believe this or not, go down.

There is no explanation for this behavior, but we have been seeing it over and over. Once you get how to do it right, you can just push it.


MK1 found that you can add another secondary and you can light AGAIN more lights on the same amount of original energy. So far, he says he has 16 secondaries.

So just play with it. Many of us are going in slightly different directions. For instance, I want to get these lights lit from .7v on an earth battery. I also want to piggy back one secondary to be the voltage source to another one...
MK1 has been pushing the output voltage tests to see if he can get household (I assume) voltage.
Ist and MK1 want to charge caps and use them to deliver the energy as dc.

We are all thinking our own ways and adding to each other's knowledge base by sharing what we find.

So, eat more than one and share what you find! 

We all benefit.

thank you

jeanna

[dog812]

Ahh i see.. thanks jeanna

So for my application of lighting 21 RGB LED's from a single AA rechargeable.. I would probably want to use a secondary..
How many twists on the primary coil and how many on the secondary do you think i should try. .. in your opinion?
I am using 2n2222 's if that changes anything.

[TheNOP]

Hey thanks for the images about coils.. I see that it is a second coil on the same ferrite..

the 2 smaller coils are the jt normal coils
one to the base the other to the collector

the third, the bigger one, is the "pickup coil".
view it as the secondary of a transformer where the 2 jt coils are both the primary coils.

But what does the secondary coil do?

as stated above it is the secondary of a transformer.

Why add a second coil?

for energy conversion.
to get a step up or step down transformer or as an isolation transformer.

[jeanna]

Ahh i see.. thanks jeanna

So for my application of lighting 21 RGB LED's from a single AA rechargeable.. I would probably want to use a secondary..
How many twists on the primary coil and how many on the secondary do you think i should try. .. in your opinion?
I am using 2n2222 's if that changes anything.

I am not sure what rgb leds are, but the answer should be the same.

I think most of us think the toroid itself is what will give you the best results when good.
Any ferrite toroid will give you the results you want.

Just start winding. If you can afford it (toroids are cheaper than the shipping) keep winding new ones and try them out on a breadboard with the same transistor and resistor etc. So, then, if you change one of those components, you can compare the toroids. Make sense?

Pretty soon you will be well informed about what is happening and you will be adding to the discoveries.

Please share what you find.

thank you,

jeanna

[dog812]

Also one thing i dont get on the diagram.. is the secondary only hooked up to the LED? not to the rest of the circuit at all? Collecting the energy from just wrapping around the coil?

Sorry i am new..


By RGB LED , i mean those ones that change colors.. from red to green to blue.. to whatever mix..

So about making the coill.... i have a local electronics store that carries all this stuff.. different size torrids etc..

I am still un certain of how many wraps i should i use? i see some say fold the wire in 2 and do 11 turns.. some say 20 turns..
And how many on the secondary?

What should i try first?