Joule Thief

[TinselKoala]

There are a number of things I would try. First the magnets are a neat idea for making the connection but you know how magnets can affect the cores of JTs, you might be killing the effect with the magnets. Next, I have found with cylindrical forms that it seems to work better if the primary (thicker, shorter wire) is wound on the outside of the secondary rather than on the inside. Finally I have had iffy results with TIP3055, some work and some don't. Why don't you try replacing the transistor with another one, even a 2n2222a, just to see if the basic circuit will oscillate..

Just some ideas... it's cool that you built it. I have one that works pretty well but it's wound on a ferrite bead that I slip over the AAA battery.

[Pirate88179]

There are a number of things I would try. First the magnets are a neat idea for making the connection but you know how magnets can affect the cores of JTs, you might be killing the effect with the magnets. Next, I have found with cylindrical forms that it seems to work better if the primary (thicker, shorter wire) is wound on the outside of the secondary rather than on the inside. Finally I have had iffy results with TIP3055, some work and some don't. Why don't you try replacing the transistor with another one, even a 2n2222a, just to see if the basic circuit will oscillate..

Just some ideas... it's cool that you built it. I have one that works pretty well but it's wound on a ferrite bead that I slip over the AAA battery.

http://youtu.be/pCeFKLeNIW4

Above is the video link.

TK:

I was hoping to surprise everyone with this cool little device but...it was not to be.  Great suggestions however,  I did remove the magnets from the connections, and I also used 2 different tip 3055's from 2 different sources and, none of the windings overlap another.  This is wound just as I have my other Jeanna circuits on a toroid.  Each winding is separated by the little O-rings on the tube.  I checked for continuity beteen the HV leads prior to hot gluing them to make sure my connections from the 26 mag wire and the 22 wire were good.  They were.  Usually when I have problems that is where it is....hard to clean the insulation from the mag wire sometimes but, I burned it and then sanded it and checked it.

I will use another transistor in there just to see if that outputs something.  Both transistors getting hot sounds like a short somewhere.  The resistor stays cool and, I even added a vr in the circuit to add up to 5k ohms and it changed nothing.

Very disappointing as I believe your idea has a lot of merit and should be explored by others as well.  This all seemed so simple when I began work on it Friday...ha ha.

Thanks,

Bill

[SkyWatcher123]

Hi folks, Hi pirate, would try winding the 2 wires together, bifilar.
Have not increased efficiency yet on the cree light, seems the yoke core is the best runner so far.
peace love light
tyson

[crowclaw]

@Pirate

Dish the base connection and see if the transistor is still getting hot, if not check the base resistance and increase it to start with. What is the current draw!

[Pirate88179]

Tyson:

Thanks, I will consider that.  There are actually three coils on this tube though.

Crow:

Good suggestions.  I will check the amp draw which I suspect is high as the transistor heats up quite a bit.  I can run my other "Jeanna" circuits for 10-20 hours and the transistor stays nice and cool.  I will try that with the base as well.

Thanks,

Bill


PS  TK,  you may be exactly correct about the magnet connectors.  I did try it for a very short time without them but, only to see if I got anything out of the circuit...I did not check to see if the transistor still heated.  Those neos are magnetizing the entire battery case and so will not allow for the field to collapse.