Joule Thief

[xee2]

@ Pirate88179

Thanks for the feedback. I tried to duplicate Freezer circuit (but I may not have). If we try lots of different circuits maybe we will find that one of them is best. You seem to have equal or better results to mine. However, without cutting diode lead I think that you are only putting energy into the tube during half of each AC cycle and so you might get better results if you change your circuit. I may be wrong, but it seems that you have your tube in parallel with the diode, so current goes through diode instead of tube when it is forward biased.

PS - noise is probably coming from transformer. The wires are pulled back and forth by magnetic induction during each cycle.

[Pirate88179]

@xee2:

Thanks for the transformer info.  I cut my connection to the board on the other end of the diode and, I have to say (subjective) the light is brighter.  So, now it is lighting on both cycles of the ac right?  The diode is no longer only allowing the one-way flow.

I modeled my board on the instructions from: http://josepino.com/circuits/?fluorescent_light

Freezer also helped me as did Jesus. (and you)  I don't recall where he said to cut the diode but, it makes sense.  Just like I don't like to see resistors unless they are protecting the transistor or some other vital component.

So, where do we go from here?  Freezer is already tying two boards together.  How much input do you think the components can stand?  For example, can we put two AA bats in parallel to up the power?  What about two in series to up the volts?  What about the use of a larger transformer?  I have salvaged some from several items I took apart.

I would like to stay with the single AA bat and see just how much we can get out of one.  So, I guess this means larger coil or coils?  I don't really know what I am doing....I know a little but I am learning a lot.

Thanks again.   ***EDIT***  Funny thing. I just re-read Jose's instructions and some q&A at the bottom of the page.  He told some guy who asked if this circuit would light a 6w bulb and Jose said no, only 4 watts max.  How are we lighting 15 watt tubes then?


Bill

[WilbyInebriated]

nice job bill!

i agree with xee, you definitely wanna be running AC to the tube. you would want the diode under certain conditions like charging a cap, etc.
that's why there is one on the first pic i posted, it was for charging a capacitor bank for a coil gun.

from here, maybe a push pull config would be better?
they can't stand +3V for very long, the transistor gets blazing hot unless you change the resistor to something higher. i changed out the transistor in one for a D2525 and it seems to handle 3V input fine with that. a tip3055.might be worth a try with the bigger transformer you mentioned. a interesting thing to try bill is to 'replace' the xenon with the fluorescent tube and put the copper strap onto the center of the fluorescent tube as well. charge up the capacitor and flash the fluoro. this will need a circuit with the cap still in it and will also abuse your fluoro. but it is pretty bright.

3V drive is gonna give you much better light. 1.5V is kind of on that ragged edge and does strange things at times, like you noted with your connections.

anyone have a 10K pot to put in place of the resistor and find a 'sweet spot'? i only got 2k's on hand  here.

[electricme]

@ bill
Cap-Z-ro has a good point, we think you have stumbled (by accident) on a way to get the tube to strike other than by normal means.
Put it aside for awhile for a think about it, and begin with another one.

I got an underwater disposable camera (Marina) the other day, and pulled it apart, dare r lots of tiny weeeeeney screws.
Next step is to see if it will work normally outa the case, then take it to bits, ha ha.

There is a biGGG capacitor, no value on it, has a blank can, so I betta watch where I put my pinkies

@all
Merry christmas to you all, and to all, happy juel thiefing

jim 

[Pirate88179]

@ Wilby:

Thank you!  I forgot to mention you when I mentioned the folks that helped me.  Sorry for the omission.  These circuit boards are so cheap to acquire that even I can afford to screw around with them.  I still have not went to my local film processing lab (I used to give them a lot of business prior to getting my digital still camera) and ask for some disposable cameras that they are going to toss out.  Like someone said, if nothing else, a good supply of hardly used pretty good quality AA's.

Can we fashion some kind of heat sink for the transistors on these boards even though they have plastic housings?  Does the transistor you recommended to me have provisions for adding a heat sink?

I am convinced that my strange operational characteristics were caused by a cold solder joint.  I usually do better than that but, when soldering on a board, my little 25 watt iron can cook things pretty quick so I like to play it safe and not get hot enough as opposed to too hot and melting the board.  I have not done much of this type of soldering.  I was amazed that my color organ circuit worked as I had to solder about 30 components on a pc board and that was the first time I ever did that.

As far as a heat sink for the original transistors on the Fuji boards, my thought would be to use a tube of the correct ID that would slide over the housing.  Maybe it only needs to be about 3 or 4 inches long but maybe that would help? (A good conductor of heat like aluminum or copper maybe?)

Heck, I have already been zapped a couple of times so now I think it is time to play.  I also want to see how long a new AA bat will light my 15 watt 18" long tube.  Maybe the components will give up before the bat dies?  Jose (the guy on the link where I got the Fuji info) says it will light for about 2 hours.  IF true, that is also incredible as I have had flashlights with 4 AA bats that were no where near this bright and would not run continuous for that long.

Again, thank you for the information and your help.

Bill