right now, i'm just experimenting. i don't have specific voltage in mind, i just made a coil because i had no idea where to start. i used 30awg because the magnets/coils are small, so i figured i needed thin wire to get any voltage. i ended up w/ ~7.5 volts per coil (x4 in series), so 30v open circuit. i have a little test motor, running around 1600rpm on 4w. to test the power of the alternator, i used some leds. each led is 3v and 20ma. i start my motor, get the stator close to the rotor, put 1 led into my breadboard and the thing bogs right down to a stop. amps spiked at maybe 300ma. i'm thinking, there's no way this thing can't run ONE led! i figure out that i have to move the stator away from the rotor, then it's working fine. i can keep adding leds, in series and parallel (again, to experiment and try to figure out what it can output) and the more i add the closer i move the stator to the rotor...i can have 25 leds running fine, but if i put one led in so that only it draws the load, the same thing happens, it spikes to 300ma and bogs down....interesting that it can run 25 in a certain configuration, but not one (i don't fully understand what is happening there). i seem to recall from the windmill books that you have to tune your coils to what you are trying to run, so i presume that is what is happening when i have to adjust the gap between stator and rotor, and that a certain gap for certain loads works. i figure at best i'm making .5w. so now, i think i want less voltage and more amps, so i'm going to try thicker wire....but if i know what a 2nd rotor will do, i can afford to go for less voltage if i can double it later w/ another rotor. one other thing i know is hindering output is, i don't have a steel backing on my rotor. i am probably losing a lot because of that. my little test motor is on magnetic bearings, i still have to test how much weight it can bear before trying to add something there.
yes, i have no idea what i am doing, but i figure the best way to learn is to play around and see what happens. just looking for some basic guidelines to point me in the right direction.