G'day everyone,
This is my first message on this board, but have been reading/following it for a while. Stumbled across it after visiting (many times) Dan & Dan's website on windgenerator building (otherpower.com).
At the moment, I'm building one myself; it will have about 1m. rotordiameter, 12 magnets (dual rotor), 9 coils (75 wdg/coil), 3phase, 12V. The coils have been made, stator is finished (apart from casting). At the moment, the rotor-plates are being 'lased' at a local company (price was good too, a cake for the employees :-) ).
Anyhow, I've been thinking (I wonder if that explains the headache): for a dual rotor generator, you need to have (in my case) 24 magnets for, say, 100W of output. But wouldn't it make much better use of the magnets to construct one with 3 rotor-plates (36 magnets) and 2 stator-coilsets? (i.e. rotor-coils-rotor-coils-rotor; with the inner rotor-magnets mounted on epoxy or something else that is permeable to the magnetic field). In this case, you would double output, with only a 50% increase in magnets.
You'd ofcourse need to increase prop-size, but you'd end up with a relatively small (qua diameter) generator, only a little deeper (and a bit harder to construct, but not much).
Anyone thought of this too? And if so, why isn't everybody building generators like this? Am I overlooking something here?
Peter Dingemans,
The Netherlands.
BTW, my hands are now a little recovering from playing with the magnets; in my 10+ years of experience as a tinkerer, I've never needed a box of band-aids at my desk, but since I've had those magnets (from supermagnete.de), the 3/4"1/2 1/4" ones, I have a box on my desk :-( I'm actually getting afraid of them, and shiver at the thought of those real beasts (2"1" 1/2"). If something happens, I may have to take off my shoes to be able to count to 10....