I need Magnets arrangement for a wind power using car alternator N42 (20x10x2.5mm) magnets are glued on modified rotor ?

Hi all, I am modifying a car alternator to a PMG .The winding system is 3 phases the diodes are still connected to have a DC voltage and the rotor circuit has thrown away. The rotor have been machined and a steel pipe is weld on it to adjust the diameter.On the surface of the steel pipe I glue the 14 N42 (20x10x2.5 mm) magnets N & S pole alternately to have 7 pair of N&S poles.The number of poles is 14/ph.I am not getting good result at 1150 rpm it gives 15 volts & at 1450 rpm --> 20 volts.But i need around 15 Volts at 300 rpm how could I get it? Please advise magnet arrangement note that gap between magnets and stator is about 2mm. Hasen

suharto_u8 years ago
you must rewinding the stator for reduce rpm to get 15v or 20v.
ramonc1238 years ago
try windblue power .com they have what u want
frollard8 years ago
If you are getting too low voltage, you might need to rewind the coils to have more wraps of smaller wire. (higher volts less amps) The voltage drop over the diodes might be causing a problem as well - are they star or delta configured? A car alternator is designed to run at high rpms for low voltage - if you can't change the innards of the alternator, you might need a gearbox to speed up the rotation (but not really advisable for efficiency and noise) Do you have pictures?