What Is A Joule Thief ?
To simplify everything, a "joule thief" is a circuit that helps drive an LED light even though your power supply is low. What can we do with it? We can use it to squeeze the life out of our old, almost drained, non functioning batteries. This project can also be considered as a green and environmental experiment, we can also use it as a flashlight that can be ran by an old, weak, almost drained battery. I even tried to use my water powered battery from my previous instructable the "Water Powered Calculator", the project was featured and displayed in instructable's front page in the "Technologies" category.
My Next Projects That Involves A Joule Thief: (soon to be posted)
- Water Powered Lamp
- Water Powered Flash Light
- Dead Battery Drainer Lamp
Here's A Video From Make Magazine:
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Signing UpStep 1: Parts And Materials
The Parts Needed Are: (click the item to know where to find/ buy)
- Round Ferrite Toroid (can be found in old CFL bulbs)- Old/ Used Batteries (can be found in garbage cans)
- NPN Transistor (2N3904)
- 1K Resistor (BRN-BLK-RED)
- LED Light
- Battery Tester (optional)
- Soldering Lead
- Copper Wire/ Magnet Wire
- Battery Case/ Holder
I want to share something. Here in the Philippines electronic parts are extremely cheap, they are extremely far cheaper from
radio shack, for example one transistor costs (2 phil. pesos - 6 US cents), a LED cost (9 phil. peso - 29 US cents) and a 1K resistor cost (25 phil. cents - 0.8 US cents). I usually buy thing from Deeco or Alexan. Usually prices here are 15x cheaper from radio shack. Price conversion - $1 US Dollar = P0.31 Philippine Peso (12/24/11).












































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Thanks for this nice instructable.
1:What happens if you hook this up to a new battery?
2: What happens if you hook it up to a three volt cell?
3:Could this be adapted to a 1watt Led that runs on six volts?
4: Could this be adapted to a flashlight, more specifically a tactical flashlight?
This looks like an idea that could go places.
2. The LED would wear out/burn
3. this circuit is not designed for that/ there are other circuits for that.
4. Yes. I made a flashlight out of it.
Good luck :))))
I am just learning about electronics:
could this same 'circuit type' be used for a
"free energy" from radio waves project?
Could someone, more qualified than me, design such a circuit?
Thanks...Vernon
Good luck! One of my first projects in electronics was the joule thief, since it is easy to construct.
to make
Its true that the RF ferrite toroids for low frequency rfi filters (hf) frequencies are low permiability, but the toroids used in the Microwave bands (a very large part of the hobbie now) and the toroids used in switching power supplies, are high permiability, even some using neobendium toroids as chokes.
Many ham radio operators often build their own radios and amps, and power supplies etc. Those working in the microwave frequencies, usually build the bulk of their radios, due to the high cost of commercial microwave radios.
Toroids lose there inductance as the frequency increases, so rare metal ( neo) toroids work much better in high frequencies
Another good source are toroids used in defunct neon sign circuits.
That was an excellent idea, to use the CFL toroids, as reusing those tiny toroids keeps one more thing from the landfills.
On a side note, Ive switched from cfls completly, to LED lighting, saving the toxic chemicals and horrendous fluctuations of life time, in CFL's, caused by cycling the on off schedule of CFLs. CFL bulbs should only be used in lights that only get turned off and on once a day. normal multiple on off daily cyclces of CFLs, cause failure in CFLs in about a year. I think LED lighting actually makes CFLs defunct.
A great idea for an instructable how to video, might be the rescue of toroids from dead CFLs.
Thanks for the great info. :-))
Canoeman
The stuff about hams is unrelated to this discussion, and doesn´t make sense to me. As for the lifetime of CFLs shortened by on/off cycles, I think you should worry more about keeping the electronics from getting hot and failing because of the heat. When the lamp´s base is above the CFL tube, the heat rises and makes the electronics get hot, so failure is more common.
LED lighting will eventually replace CFLs, but at this time very few people will spend twenty to forty dollars (US) for a single LED lamp when they can buy a CFL for 1/5th of that. And those are the prices we find in the Big Box discount stores! But given the time, the LED lamp will pay for itself in electricity savings. Another issue that seems to still plague LED lamps is that people think that they are all ¨too bright¨ or the light is too much like daylight. Nowadays the warm white LED lamps are available, too.
If you want to learn more about CFLs, go to http://donklipstein.com/ and read about CFLs, LEDs and fluorescent lighting.
About the only thing I agree is keeping the stuff out of the landfills. As for a video on salvaging toroid cores from dead CFLs, I think I´ve already seen something about that on Youtube.
The observer must view what happens in the Joule Thief in the time domain, not in the frequency domain.
I suggest you back up your claims with a link to an authoritative source. That way, if the reader doesn´t understand your verbiage and double-talk (most likely), he/she can read more about it elsewhere.