Understanding 3 phase alternators
Word "Phase" refers to the magnets passing over the coils at different times. There are two types of wirings for alternators:
- In single phase wiring, all the magnets and coils line up with each other.
- In 3 phase wiring, 2 extra coils slightly out of phase with first.
There is more detailed, complex but otherwise fine examples are available at
- http://www.windstuffnow.com/main/3_phase_basics.htm
- http://www.sawt.cn/News/HomeMadeWindTurbine/49.html
- http://samarium.vitatechindia.com/SamFolder/SamHelp/index.html?hm_current_in_wye_connected_motor.html
Car alternators are considered to be a poor choice for wind turbine. However, Car alternators can be used by rewinding a 12V car alternator. with modified rotor with N42 magnets. But in this way you will get less volts than required at least 15 V at 300 rpm or even at lower speed. You need to get 5 times the number of turns on the stator with wire of a smaller gauge. Measure the diameter of the existing wire, calculate it's cross-sectional area, and find a wire 5-6 times smaller in area. That will reduce the current by the same factor.
