I thought of another dumb question about what you're doing here. What is the source of power for this, the rotation? If it in itself is only a small force, will loading it down, by generating a voltage, be a problem? You do remember the old,"there is no free lunch" saying? And if there is an electric motor diving the shaft, wouldn't a convertor/ invertor from the motor supply make better sense?
While they do make a 'sine wave' type output it really isn't AC, especially if all of the magnets would be the same polarity. It would/should look more like "half wave rectified AC" than AC.And another thing, from what I've seen documented online, this device will produce an AC waveform regardless of the magnet's orientation. This because it appears that a current is induced in one direction when the gear's tooth approaches the magnet and then it's induced in the opposite direction when the gear's tooth moves away from it.