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Topic: Small powersource based on motion needed! (Read 9 times) previous topic - next topic

dieselboris

Hi all,

Dunno whether this is the right place to ask this but i'll give it a try.

I want my bicycle light to be powered on the sideways motion of my bike. For this i would need a device which is also in 'automatic' watches like the seiko kinectic (they do not require battery but winded up by the motion of the wrist).

Does such a thing exist in electrical form (the watch version being mechanical)? And if so, would the power be large enough for a LED to burn?

Thank you! 

Far-seeker

It's possible, but you'll have to use at least a small rechargable battery. Otherwise the energy will be produced too intermittantly and likely in amounts too small to continously run one or more LEDs.

Piezoelectric vibration sensors can be used as small-scale energy harvesters.  If you go this route should use a dedicated energy harvester IC, like the LTC3588-1.  Sparkfun sells a small circuit board built around the LTC3588-1, you'll probably find other options after a little googling.

wanderson

I would be surprised if a bicycle that stays upright would have enough sideways motion to generate useful power for a light.  Please let us know what you find when you start testing.
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dieselboris


I would be surprised if a bicycle that stays upright would have enough sideways motion to generate useful power for a light.  Please let us know what you find when you start testing.


i'm hoping for the sideways motion when you're accelerating. The primary target group are those fixed gear track bikes. But i'll let you know if anything comes out!

Grumpy_Mike

Well I would say you have no chance to get this to work. Have you seen those torches that light with reciprocal motion you get in Discovery shops. That gives you some idea of the mechanical to electrical conversion rate you can expect.

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