Joule Thief

[detrix42]

Hmm..that would be hard task because TV flyback likes to generate much more then 1000v 

so your saying that if I hook up a JTC to a flyback transformer, I will get over 1000v???  From a AA batter no less???  wow.

[MrMag]

Ok, I am in the process of removing the flyback transformer from a 32" american television. Due to the high voltage that this thing can generate, I would like someone from this tread to walk me through steps to hook up a joule thief output to this flyback transformer.  I only want about 1000v for now.  I am trying to look up the pinout but I am not gettng anything from google with the part numbers I am seeing.  (TFL2AA002 from a panasonic tv).

Here is a simple way to figure the pinouts in the flyback. First, check all of the pins with your meter. The set of pins that give you the least resistance will be your primary. To find your seconday winding, you will need a 12VDC supply or whatever you have handy. 24 would be better. Connect the positive of the power supply to the high voltage wire, the red wire that attached to the picture tube. Connect the negative from the power supply to the negative lead on your battery. Now take the positive meter lead and test each pin on the flyback. You should have a voltage on only one of the leads. This will be the secondary winding. If you don't get a voltage reading, try reversing the + and - on the power supply. Some of the newer flybacks have a built in diode on the secondary winding.

To hook it up, joule thief style, use the primary winding and then wind a second coil on the flyback ferrite to feed back to the transistor.

This should either help you or totally confuse you. I hope it helped.

[conradelektro]

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To all experimenters who helped me (Jeanna, Pirate88179, Gyulasun, Crowclaw),
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your efforts were not in vain, after some trial and error I got a JT which is nicely lighting up three red LEDs in a row. See the attached images and the scope shot (its now 3.5 KHz). The frequency depends a lot on the number of turns of L1. The fewer turns, the higher the frequency. My blue Toroid needs quite a lot of turns for L1 (10 turns, see the attached schematics).

The hint about the value of the resistor between L1 and the base of the transistor was very valuable, it needed 330 Ohm.

The circuit consumes about 20 Milliamps when lighting 3 red LEDs in a row. On the scope shot you see, that the duty cycle over the LEDs is quite short, I guess this explains the surprising low power consumption.

The circuit and the toroid are now ready for a third winding (on top of L1 and L2) in order to implement Jeanna's light, which I will attempt soon.

There are better Toroids than the blue painted one I am using, but I wanted to make it work with this one, before I move on to other cores.

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.

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To Detrix42:
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Once I am a bit more experienced with the JTs, I want the same as you, namely driving light tubes and the new energy saving bulbs. For this I am studdying the thread

http://www.overunity.com/index.php?topic=8977.0 ( GBluer(Slayer) Exiter )

Read the posts of slayer007 and watch his videos on YouTube.

Greetings, Conrad

[Pirate88179]

so your saying that if I hook up a JTC to a flyback transformer, I will get over 1000v???  From a AA batter no less???  wow.

If you use a Jeanna's Circuit, you can get over 2,000 volts output (or less if you want) using a simple TIP3055 transistor and running on a single AA battery!!  No flyback coil needed.  If you do use a flyback coil or car ignition coil, I would think you would have to rectify the JT's output as it will be a high frequency AC and not dc.

Less turns on the pick-up coil of the Jeanna's Light circuit will give you less voltage out and you can make it output whatever you need.

Lidmotor has a great schematic at the start of his video located here: http://www.youtube.com/watch?v=11nzbi59T7w&playnext_from=TL&videos=TVF4g87eQFw

You can do a screen capture and blow it up, that is what I did.  Jeanna has also posted her circuit here as well but I can't recall what page.

Bill

[detrix42]

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.