Hi James, don't get discouraged, but you need to start a couple of blank documents, and then copy/paste any applicable paragraphs you find that are helpful to what you are looking for.
The 10' diameter windmill on the home page is the result of many years of research by some very intelligent and sincere enthusiasts. Compare everything you learn against the way that this alternator is laid out.
I am a newbie too, and I will probably butcher the explanation I'm about to give you, but I will give you what I "think" I have learned recently from this site. (grab a cup of coffee, and if you're really quiet, you can almost hear the laughing!)
If you take a coil of wire, and spin a magnet in the center of it, a meter will read out a small "burst" of voltage from the two leads, then (if the magnet continues to spin at a constant RPM) it will drop to a lower but constant output. The drop is due to built up resistance to flow, and if we can find a way to make use of a bunch of overlapping "start-up" pulses, we can double the output without making the expensive magnets or coils bigger.
By making a ring of coils and passing magnets near them there will be a series of pulses, and it was also then found that if you alternate the direction of the pulses, you will get an even bigger output from the same size alt.
If a set of coils is all connected together like a ring of people all holding hands, and at the same time, you have a rotor with the same number of magnets, every time a magnet passes over a coil all at the same time, the output would noticeable "pulse", and a bulb connected to this would visibly flicker. This is called "one phase"
Two-phase is slightly smoother, but 3-phase has a fairly smooth output. If you are converting an electric motor to an alt, and it has an even number of coils, you may wish to make it 4-phase (or more) rather than the flickering 2-phase.
If you are making a Permanent Magnet Alternator (PMA) from scratch, and you are certain you want 3-phase, you will need to make 3 coils per 4 magnets. If you make an oval coil of copper wire, the two long sides are the "legs" and the short ends just connect the two legs. When two opposing magnets are over the two legs (N facing one leg, S facing the other), one magnet is pulling electrons, and the other magnet is pushing them. Any extra copper wire outside the magnetic flux field will make the path longer (adding resistance) without adding to the coil output. Most builders consider a wedge shaped coil with two slightly narrower wedge shaped magnets sitting over the coil legs to give the biggest output from the smallest alt.
The size (depth and shape) of the strong part of the magnets flux field determines the optimum coil size and shape. Once that size and shape is determined, the best volume of copper for the coil is set. Many wraps of a small diameter wire will provide a higher voltage but lower amps due to a long path with a lot of heat from resistance. A few wraps of a fatter diameter wire will provide lower voltage but higher amps with less heat.
The invisible magnetic field of a magnet is called its "flux" and if you take a round magnet that has its north and south poles on the flat faces, you can put this magnets edge under a piece of paper and sprinkle iron filings on top of the paper to see the shape of the N and S fields. If you put a steel plate on one side of the magnet, it will pull in the flux on that side, and strengthen the other side. If you place an opposing magnet with a steel backing near the first magnet, the flux between the two will be very strong (N facing the stator on one side, S facing the same spot on the stator but on the other side). Two magnetic "rotors" spinning with a stationary "stator" of coils in the middle is called a dual-rotor.
The magnets are stronger the closer you get to them, so the distance you place the magnet to the coil is called the "air gap". Since the magnet wants to stay by the metal coil (called "cogging"), a big air-gap will allow it to spin in light winds but have a lower output, a close gap will require a stronger wind before it will begin to spin, but have a higher output once it does begin spinning.
An "axial" is like a pancake spinning next to another pancake that isn't spinning. A "radial" is like a soda can spinning inside a slightly larger soda can. When you convert an electric motor to an alt, it is a single rotor radial.
When you have 3 coils for 4 magnets, two magnets will be located properly at any given moment to push/pull on a coil, and another coil will have a magnet set falling off, while another coil will have a magnet set pulling into place. For 3-phase you can have 3c/4m, 6c/8m, 9c/12m...depending on the size of your magnets and the size of your spinning disc.
If you wire the coils in "Star/Wye" it will provide higher voltage, but lower amps, if you wire them in "Delta" it will be the opposite, lower volts and higher amps.
I don't understand wiring the coils in "series or parallel" yet, but each has its benefit and drawback, depending on the application.
"cut-in" is when the alt begins spinning fast enough to actually start charging your battery, and "furling" is when the windmill begins spinning so fast that a mechanical device turns it away from the wind so it doesn't fly apart (and it then stops charging).
A transformer will change high voltage to low voltage, and a rectifier will convert AC to DC. High voltage will travel farther without weakening, so, in this way a high-voltage alternator on a windy hill can provide a low 12/24/48 volts DC to charge a battery pack in your garage.
There are many ways to make a generator, depending on what you can afford, or what you can get free/cheap, but this seems to be the best bang for your buck/time/effort.
