Hi all, Would appreciate some help with the magnetics in a contactless dynamo I'm trying to build for my road bike to power some LED lights. I've got 8 rare-earth magnets mounted on the bike wheel, near the hub. They're flat, round magnets, around 2cm dia., mounted all the way around the wheel. I've then got a coil (approx 5000 turns) mounted on the fork with a ferrite core, which is perpendicular to the magnets, and as close as possible to the magnets. It kinda works, but not as well as I hoped. I'm gonna try a bigger coil, but I have some questions about my set-up. I understand that I'll get the most induced voltage in the coil when it cuts through the most lines of magnetic flux. To do this, I've got the magnets closely spaced (almost touching), and of alternating polarity (so the coil alternately passes a N pole, then an S pole, etc, as the wheel spins). Is this correct?