Spotted in the MAKE Flickr pool:

Flickr user Lucky Larry built this shakeable dynamo using a few rare earth magnets and a bit of wire. If you’ve been wondering how to make one of these, he has a a four part series, which covers everything from how to wind the coil to how a bridge rectifier works.

  • Mike Yancey

    He uses a ‘1n004′s’ (possibly 1N4004?) – a regular diode will have about 1V forward drop. Better choice would be a Schottky diode 1N5817 (1A / 20V), which has a 450mv drop.

    Doesn’t seem to use any sort of ‘holding’ capability – stop shaking and the light stops – possibly could use a 10uf electrolytic to buffer up some of the charge. Might give a bit of extra glow after the shaking stops.

    Mike Y
    Dallas, Texas

    • Matt Mets

      Good point about the diodes! I think he is working on a way to add some storage capacity next, it really isn’t very useful as a light source in it’s current form :-).