Joule Thief

[resonanceman]

@ resonanceman

Here is a simple trick you may want to try with your non-toroid JT. You could problably get the same performance with one transistor and a heat sink, but this will let you push more amps without a heat sink. The advantqage of no toroid is that you can use a lot of amps without worrying about the core saturating (since there isn't one).

Xee

With my 3055   I don't have any problems  pulling amps
With  the  pot  at its lowest I have seen  1.25 A  quite a few times
I  have been running  2 AAs  some of the time ......I have  seen  2.5 A at times .......I don't like to keep  it  on the high amps ....... 
I  usually do not run on  high amps ......  almost always with my LMs  the  sweet spot is  quite a bit less than max  current .
I do have a very nice  heatsink on my  3055  just in case




gary

Edit

I  just looked  at your  schematic  again .......I missed the  voltages  before.
I am thinking  that  I might  be able to  almost substitute feet for  wraps .

I am thinking of  putting all of the  pairs   in the  cat5 in series (for  a secondary ) and   adding a primary  with different wire .........that way I can tune  it better .

[jeanna]

I agree that   the frequency might be higher




gary

My frequency went way way down when I removed the core on that Stubblefield generator.

From 41.6KHz with the bolt in place,  to 7.57KHz when I took it out.

Gary,
I wanted to confirm that you are using one battery?

thank you,

jeanna

[WilbyInebriated]

i posted an aircore back at the beginning of the thread, somewhere. man it's huge now.
here it is.
http://www.overunity.com/index.php?topic=6123.msg143373#msg143373

it ran as bright as any of the 'cored' simple jt's that i have, with less draw than most if i recall. higher freq. too i thought? i am at the lake so i can't do any hands on measurements on it at the moment.

[jeanna]

i posted an aircore back at the beginning of the thread,

Oh I am caught again.
On that page YOU had the presence of mind to say basic joule thief.

That reminded me that I was referring to my secondary output for frequency and voltage with a light in the basic jt light place.

I actually do not know how I would measure the frequency of a basic joule thief.
Would it be across the C-E junction?

Thanks,

jeanna

[TheNOP]

I actually do not know how I would measure the frequency of a basic joule thief.
Would it be across the C-E junction?

yes.
in fact to get the frequency you could connect almost anywhere.
at the battery, between the - of the battery and the transistor's base,  between the + of the battery and the transistor's base.
it does not really matter, the frequency will remain the same.
only the amplitude and the current phase you will be measuring will change.

the frequency will remain the same unless you are actually interfering with what create it.
ex: your probe's parasitic capacitance interfering at very high frequencies(vhf/uhf).