Joule Thief

[Pirate88179]

@ Pirate

Bill,  Great work!   How long does it light with one AA battery?

Bill

Thanks.  I have not tried to see how long it will light as of yet.  I will probably wait until I can rig up a heat sink for the transistor before attempting that.  All of the pictures I have posted using this circuit and the various experiments have all used the same AA bat.  I am guessing the total run-time on that battery is about 45 minutes or so.  But, I have been using larger and larger tubes as I go so, I have no idea how long it might run with the 40 watt tubes.

@xee2:

Thanks for the warning.  Geeze, that's all we need.  I was just getting to understand this circuit and now, maybe we can't get them anymore?  When I get a chance, I will try to pick up a few more to see if they are the same as what I started with.  Be good to have them around.

Bill

[xee2]

@ all

The board in the new camera I bought has a red LED instead of a clear neon bulb. I guess LEDs are cheaper so they changed the board to use them. The other components seem to be the same. Packaging was 100% the same for both cameras.

[Pirate88179]

@ xee2:

Mine did not have a neon, it had an led.  I don't remember what color, I dumped it into my LED supply box when I removed it and it is mixed in.  Maybe you now have the board I am using?

I have been working tonight but if I can, I will try the two tubes and see what happens. I may fry something who knows?

Bill

[xee2]

@ all.

Steps I took for Fuji board with LED (no soldering required):

1. REMOVED LARGE CAPACITOR. Short with screw driver first. This can be left on board but is large enough to cause serious damage and should be removed just to be safe.
2. Cut lead at anode end of diode and fastened one end of tube to lead at cathode end of diode (end with the line on it).
3. Connected other end of tube to battery negative clip.
4. Shorted little lines on one side of hole to the lines on the other side of hole (on trace side of board where shown in my previous photo).


EDIT: Same steps will work for Fuji board with neon bulb.

[Pirate88179]

@ xee2:

Great!  Will it light the larger tubes this way?  Your way is a lot easier than what I did.  If it works the same, less work is better.

Bill