Joule Thief

[detrix42]

[A author=detrix42 link=topic=6123.msg235096#msg235096 date=1269795045]
@all:  Here is something I am figuring out about the Joule Thief.  With my current setup, it does not matter what the input voltage is, I still get 120v out.  This is why a 1.5v battery drained to .5v can still power an LED.  This is very interesting. So what do I have to do the get more voltage out.  I would love to power my Newman motor with only 1.5v input.  My guess is the number of windings in the larger side of the coil.  So I will definitely want to try an automobile's ignition coil. 

I believe you only need enough to bias the base-emitter junction of the transistor.  And perhaps the speed at which the transistor can be switched on and off plays a factor in how much I can get out of a JTC.  Hmmmm...............................

I have included a schematic of my setup, which seems to be the best efficiency (voltage wise, most bang per volt).  I did not include a voltage value, because it seems to not matter.


Hi detrix what transistor and diode are you using?
Thanks

I have gone through a few transistors.  Just a general NPN.  currently I have a 6256N719, and the diode is a general purpose 2n4007

Nothing special here.

[Mk1]

@detrix

Usually the transistor dose make a huge difference in the results , try 2n3055 or 2n2222 , but the transformer you use will not give you that much more .

Mark

[slayer007]

Hi A

Always testing the main coil  and today i could get a nice very stable 2mm long plasma arc with about 100 ma at 12 volts.

What is remarkable is that the Arc does not appear when i turn the current on. I have to light my CFL tube first   (by contacting the main coil)  than i have to slowly get away the CFL tube until the light desapears  and only than the plasma arc is on.

It seems to be the necessity to turn the coil outer power on.

Very interesting

Can you explain why we need to turn this outer power on ? And can somebody explain me what is the power in a plasma arc.  The smelling of ionised air is quite strong and depending of the gap distance it can burn my table. !

Regards

Laurent

Nice one Woopy.

I started a new thread for this under.

http://www.overunity.com/index.php?topic=8977.new#new

[detrix42]

detrix,

   Less turns on primary and more turns on secondary, you can get over 1kv. Another example is winding three coils on a 2.5 inch toroid core, 2 turn primary and 10 turn secondary (JT), with the collector at 80 turns.  Those little flash camera circuits also put out over 1kv. 

http://youtube.com/jeannacav
http://youtube.com/lidmotor

e
east

Thank you Estov, but I am having some difficulties. Its probably something I am not doing quite right.  I dont have any ferrite toroids that big available, so I am trying a speaker magnet about that size.  I tried the 2 windings and 10 windings (actually I did more like 20 windings), but this could not even light my LED.  I wanted to get the JTC part working before I added the 80 turns.  So I am not sure what I am doing wrong. hmmmm......

[Pirate88179]

Thank you Estov, but I am having some difficulties. Its probably something I am not doing quite right.  I dont have any ferrite toroids that big available, so I am trying a speaker magnet about that size.  I tried the 2 windings and 10 windings (actually I did more like 20 windings), but this could not even light my LED.  I wanted to get the JTC part working before I added the 80 turns.  So I am not sure what I am doing wrong. hmmmm......

You can't use a speaker magnet, or any magnet of any kind for the toroid.  The entire trick to all of this, as I understand it, is the ability of the ferrite to very quickly magnetize when energized and then demagnetizes very, very quickly which give the spike of the back emf which is where all of the energy lies.

Soft iron (meaning iron that magnetizes quickly and demagnetizes quickly) will work also but, you do not ever want to use a magnet.

I hope this helps.  Please ask more questions if I have not been clear here.

Bill