Bike wheel alternator - good design?

[Gotwind Ben]

The bike wheel alternator design makes a lot of sense, speed being the advantage,i.e. locating the magnets on the circumfrance of the wheel, centrifrugal forces shouldn't be a problem, not sure on this.

I made a little test coil along similar lines with 8 magnetic 2" x 1" x 1/2" thick poles, but never pursued the idea, maybe I should soon.
This design also allows the ability to mount many poles also, 24 or 36 maybe, making a very low rpm alternator, not hugely efficient as there is no return magnetic flux path, but reasonably cheap and easy to make in a DIY style.
It showed great promise.



Not so sure of the blade design of the video though Vic.

[Gotwind Ben]

You could probably make a reasonable horizontal turbine using a std 26" steel rimmed bike wheel.
8 magnets fitted along the rim (the opposite of the above idea) - and six (1 ohm coils) fitted on the outer edge (somehow?).

An 'old style' water pumper blade arrangment could be fitted within the cycle wheel to give some good torque, speed not quite so important with this arrangment.

A very old idea from way back rears it's head again :D

Looking at that pic of the bike wheel genny, and regarding the lack of return flux path behind the coils. What about the plastic-coated garden vine wire you can buy, just wrapped around and around the circumference behind those coils?. You'd certainly get hysteresis and eddy losses, but not cogging. I wonder, would the increase in efficiency from adding a return flux path with ersatz insulated laminations (but of low resistivity material) be greater than the added losses in such a low-rpm device.