The Joule Thief (or just another white LED torch)

The Joule Thief (or just another white LED torch)

Alex writes –

“Here’s the schematic, it works as a voltage converter to draw just 20mA from a 1.5V cell to light that white LED. The term ‘Joule Thief’ is used because the circuit will work from a cell which would otherwise be considered spent. I found that if the batteries in my Gamecube Wavebird controller stopped working, the same “spent” batteries will quite happily run this torch for a couple of weeks. Continuously.”Link.


  • HOW TO – Make a Joule thief – Link.

12 thoughts on “The Joule Thief (or just another white LED torch)

  1. says:

    This is a great idea to make them for all the dead Batt. you have around!

  2. pelrun says:

    Big Clive has a joule thief which is tiny enough to fit in the case of an old torch bulb!

  3. pelrun says:

    I should have checked the HOW TO link at the bottom of this post, as it already mentions Clive’s circuit. Whoops! :D

  4. wai_xing_ren says:

    That image reminds me: I found a ghetto way to make a “circuit board” with friendly plastic and copper wire. When the plastic is still soft–or after you’ve softened it with a lighter (actually a hot air blower would be ideal)–you can press wire or components into it. Using this method you could make both the battery case and the board for small projects.

  5. GOD says:

    The Web site mentioned in this article has moved…

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