Quote from: Pirate88179 on August 06, 2013, 09:03:34 PM
Nice.  What was the voltage on that 1F supercap? 2.7 volts?  You can light that bulb very nicely on only 1.5 volts (or less) using the Jeanna Circuit or a modified flash circuit.  It will be on all of the time, and bright too.  Very good job for that small toroid though.  Well done.

Bill

Thanks for good comment. The voltage was 4.8V, but it is working on 1,2V also. Primary and secondary of toroid have 20 turns. Thanks for Jeanna Circuit.

Quote from: Pirate88179 on August 07, 2013, 01:31:20 AM
John:

Here is the Jeanna Circuit.  The flash circuits are very board specific depending on if you have a Kodak, Fuji AA, Fuji AAA, or no name surplus board.  If you find or have a board, I will be happy to try to tell you how to modify it.

Bill

Thanks Bill, I have the parts. When I get some time, I'll play too. John

Quote from: Pirate88179 on November 20, 2008, 03:07:58 AM
Can anyone of you electronics guys answer a question for me concerning the Joule Thief? OK my question is this:
The plans I have call for a 1k resistor.  From everything I have learned in electronics thus far, resistors limit the flow and dissipate overage as heat.  This seems wasteful to me since the idea of this device is to improve efficiency, as in use all or most of the available energy in a battery or similar system.  I am wondering why the resistor is needed?  If it gets "warm" at all it is wasting power correct?  Is this required to protect the transistor?

I would really appreciate any input here as this is my first Joule Thief.  I know they have been around a while and I have a pretty good idea on how they work, at least in relation to the lighting of LEDs.  I am also going to experiment with these using supercaps as the power source both with, and without batteries.  This will all be tied into my work with earth batteries from which I can already light an LED.

If I need the resistor to protect the transistor, then fine, that's the way it is.  It just seems a little counter intuitive from my limited electronics knowledge at this point.  Thank you.

Bill

YES YES   Heat is wasting your energy gain.   a magnetically quenched spark gap  can do that job.  Perhaps in a gas field or vacuum best.  Two bowl shaped fields to contain the gained field would be efficient.

  Bill:
  The Joule Ringer circuits use no resistor, although a trim pot can be incorporated. Those Ringer circuits have also been used to light even the newer type of single Led ac bulbs. Like the type that you mentioned earlier, and they have been shown to work well with them.
There are some videos out showing that.
  I still am interested in finding the self running aspect of these circuits, as the feed-back path back to a battery, to recharge and maintain it up, should be feasible. Or only needing a battery to jump start the circuit, and once started not needing any more.
Yet no one has shown a self runner. That is still running...

Nick:

Thanks, I'll have a look at the ringer and the super ringer circuits to see if it is something I might want to build.  If it is wound on a rod then, i like that as the winding is soooo much easier than a toroid.  That is a plus by itself.  No resistor you say?  I have heard of this circuit, of course, but have not payed much attention to it...I probably should.  I believe they run on 12 volts?  If this is true, then probably why it did not interest me.  Maybe one could be made to run on 1.5 volts?

Thanks,

Bill