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

  2. 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.

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