Joule Thief

[slayer007]

@ flathunter

Why don't you make the slayer007 circuit?

It will allso work better if you have a rectifier off the secondary coil and have a capacitor across it.

The light will stay brighter, It should keep around 300v on the cap when the lights on.

[Mk1]

I got  the  rest of my parts in  today ........so  it is  time  to get  busy   

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I  have a couple  of  questions .

On  most of the JT  schems  there  are black  dots  on one  end of the  the windings.
I am pretty  sure that  they  are  to show  winding  direction  or something  but  I wondered  what the  exact meaning  of the  dot  is.




I   have  read  a few times that the JT  core  becomes saturated ,   Is there a practical  way to tell   when  the  core reaches saturation ?
I think  this is  important  because I am planning  on  working  towards  a mag amp  type  of JT.



I hope that  someone   can help   with these  questions ..

Hi , welcome again ! Yep the dots show polarity , but it could be done in so many ways , usually means the coil input is North (positive side) the output is South (negative)

There is a magnetic amplifier book on this side , worth to have a look at , saturation all toroid are different and if no data , it needs to be tested , a scope would be helpful , i don't have one , so i can't help there , but get it to work first worry later ?
Someone will help for sure.

Mark

[Mk1]

@all

Mk8 first test data , 2n2222, 92 volts rectified X 16 . On a 1 inch green gem toroid , i will tune some more , but looks good , btw 2 layers thick.


Mark

[jeanna]

Jadaro,
I am sorry to hear about your ears. take your time and get better.

I am uploading a change to your drawing that represents my request to you.

I had a high permeability toroid which gave lousy results. I am impressed with the low amperage results you are seeing and I am curious about how the toroid itself is changing things on your circuit. (also how it compares to the high permeability toroid I used.)

Anyway, I hope this clears up what I am asking for. Please measure the amps draw and the volts and the original battery voltage as measured when you make the test.

Thank you,

OH and, I really do recommend that you try to wrap a few turns of another secondary through the center of this toroid and see what the lights do from that. (this means after you prove the circuit works with the light as you have it, pull it out and see about lighting it with the secondary ...)


@Gary,
Hi

Yes, those dots indicate that the coils are going in opposite directions. It happens when you twist the wires as described in the make a joule thief instructions. You don't need to decypher it.

It seems that it is what makes this little jewel work. The self inductance that was the enemy of some (and which NT fixed with his pancake) is not at all the same problem here while the jt is making the ac out of the nearly dead battery.

jeanna

jadaro pic follows

[resonanceman]

ist!

i may be able to find a few fets...      to do this ....  key is to keep the spikes with in working range ...     so you dont start popping fets...

IST

I just  got  some MOSFETs  from   Electronic Goldmine     2N7000   I am going to try to get  them  to work in a JT  soon.

http://www.goldmine-elec-products.com/searchprods.asp


gary