Hello everyone!! On this instructable you will see how to build a simple contactless dynamo for powering a bike safety light from a relay coil and some hard drive magnets.
As you will see, the electric circuit is really simple and contains only 3 bright red leds and a 4700uF capacitor. The capacitor is used just to keep one of the leds steady while you are driving. The other two leds will be blinking as the magnets pass by the coil. To have all three leds blinking you can remove the capacitor if you want. If you decide to place some more capacitors in parallel, the steady led should keep on even when you're stopped.
On part two we have more 2 coils installed for powering 5 white bright leds for the front light. The circuit is completely independent from part one's.
For more information about how to improve this kind of system, just look around the site, there are several instructables on the subject. You will find different kinds of generators and other circuit ideas.