Joule Thief

[Sprocket]

ok, I found a schematic of the whole circuit board for the tv.  I will include it here.  I don't see where the High voltage wire that goes to the tube is.  argh.

The pin marked "EHT".  The standard o/p voltage from these babies is around 25k, after going through the 'tripler' - though it of course depends to your primary voltage...

[detrix42]

ok, ok.  The Flyback transformer may be a bit overkill.  I am considering it because I don't have access to a 3.5" toroid.  I have a bunch of 1" toroids, and a couple of disposable camera flash transfromers.  hmmmm.  I still don't know how to use the output of the joule thief in my motor.  My third motor's coils have a resistance of 1155ohms. This draws to much from my JTC. I plan on adding a lot more wire when funds allow.   

So in the mean time, I would like to get the Flash transformer to lite a CFL.  I think I can do this.

[tysb3]

Hi  detrix42
with soldering iron 60W you can remove rod from flyback transformer.
need to heat rod about 6-10 min (glue become soft), after carefuly release by knife.
maybe need heating twice or more

[resonanceman]

ok, I found a schematic of the whole circuit board for the tv.  I will include it here.  I don't see where the High voltage wire that goes to the tube is.  argh.

Detrix


you don't  need  a schematic to make  a flyback  coil work as a JT

Just  check the continuity  of all the pins.
The  high voltage lead coming out of the  top  will probably  have  continuity  with one  or 2 pins.....  this is your secondary.

you  will probably  find several pins  that  have continuity in a row.
These should   be low resistance  .......  these are your primarys.
Just connect your  C , E and B+  to these  pins and  check  for  output
I do not  know what kind of voltage  these will put out...... my meter only  goes up tp 600 V .....it is higher than that.

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SOmeone   posted the  standard  connecrtions for  flyback transformers  on the JT thread.........it has been a while....... I have no idea how  far  back to  look.


gary

[resonanceman]

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I am thinking a lot about an air core coil and will do some experimenting in this direction. Specially with three windings (for Jeanna's light) I see (more like a blind man) a lot of potential in a coil without any core. I am very much influenced by the GBluer(Slayer) Exiter.

conradelektro

Air core coils are no problem......in general  you just need more wire than  if you used  a core.

It is possible  to light  a LED with only  a twisted  pair  of wires.
From my experience the pair has to  be at least 6 ft long.

It may  seem meaningless to light a diode  with  just a wire.........below  is  such  a JT .......only I have wrapped  the wire a few turns around  a toroid  with  a secondary .......it is driving a 90 LED array

Edit
When adding  toroids in this manner  you can use  a shorter twisted pair........ if you add a few  toroids you may not need  any extra twisted pair other than for  connecting ther toroids.

If  you add too many  toroids  the inductance  will choke the circuit...

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I have also  made a JT out of  150 ft of cat5 cable.
I used one pair as  primary and  connected the rest of the pairs in series  as secondary....  it  worked  very well........but it was very large.


gary