Hey Rich,
Thanks for posting and considering.
For your information I've attached a screen-dump from one of the bicycle power calculators available on the internet. Speed is moderate and the power is about 114 watts. 6 watts+ will add to the load, however, I can switch it off and I do have experience with riding heavy loads. So I consider the challenge of delivering ~6 watts to be manageable from my perspective ... Also, as I mentioned in a previous post it is not an option to use a hub dynamo ....
Whether or not it's possible to generate 6 watts using this kind of "generator" I don't know ... That's what I'm trying to find out
.... now I've tried with more windings (3x - altogether about 60 windings now) and output is increased to 170 mVs. However, it's not a very "stiff" voltage as loading with 6,8 ohms reduces output voltage significantly and beyond the voltage drop caused by the internal resistance of the wires.
I've also checked the magnet field orientation, as you suggested Rich, and it is perpendicular to the windings - rotating the field 90 degrees reduces output significantly.
I've also tried to add another set of magnets - double thickness - but it doesn't increase output (probably relevant that the distance to the coils is increased by a few millimeters as well).
Angular velocity is about 1 meter/s which will increase to about 3 meters/s riding the bike at 20 km/h. If that's a linear relationship that would increase voltage by a factor of 3.
Maybe it's a question of larger magnets, placing them closer to the coils, increase the number of coils, and increasing wire diameter? That I can do, yet if one of you have inputs on correct size and placement of the coils relative to magnet size, I'd appreciate this ...
Evening is approaching here in Denmark - the best for your evening,
Jesper