Contactless Dynamo / Generator
I am wishing to add some sort of dynamo to my bike to power lights. The main reasons are if the batteries get low I will forget to change them, and I will probably forget to turn the lights on. So off I went to eBay and bought a Â£4 generator and light set. It arrived and today I have been attempting to fit it - to no avail. I have a mountain bike with full suspension so there is no where suitable to fit it to.
So back to the drawing board. I came across FreeLights. The idea itself looks promising (unlike their spelling), however their implementation probably wouldn't be any good for me as it appears to be aimed at thin framed bikes - hacking probably could be done, however I would like to roll my own solution, and create an Instructable in the process!
So anyway, if you are too lazy to read the webpage above, here is how it works:
- A magnet is attached to the spokes
- There is another magnet in a container
- The container has wires around it
- The container connected to the forks so the magnets brush past it
Basically it is like a cycle computer sensor, but it produces lots more electricity! I like their idea, but it seems rather inefficient as the magnet is just randomly spun hoping for the best. They offer a kit version which appears to use a spherical magnet, but even so it still seems rather inefficient to me.
So on to two other possible options. The first is basically the same idea, but the magnet is fixed so it can only spin in one plane. Something like this [Ultra-simple Electric Generator]. The other option is to get rid of the spinning magnet, and instead just have coils like the various wind turbines on this site.
So basically I want to know which method is the best, and given that how I can maximize the power produced. I am thinking just increasing the number of turns, stronger magnets, greater number of magnets on wheels, greater number of 'generators' etc. And then realistically, what sort of power I would be able to get?