A blog about mi projects that involve renewable energy.

http://dimyselfpower.blogspot.com/

DIMyself power

A blog about mi projects that involve renewable energy.
Saturday, August 14, 2010
Alternator
A common misconception about wind turbines is that they are generators, as in wind generators, in fact most of the turbines produce alternating current or AC not direct current as in DC. The main reson that AC is used in wind turbines is that it is much simpler and reliable to build an alternator than the same rated output generator.
I am building a PMA type alternator ( Permanent Magnet Alternator ). I made my decision to choose to build a PMA mostly because of it's simplicity, the way a PMA works is just so foolproof that even a child could understnd it.
3phase alternator
If you have even the slightest imagination you could visualise that the magnet ( white with N and S labels) turns and by doing that it's magnetic field turns with it. When a magnetic field moves thorough a coil it generates electricity in the coil ( marked as red green and blue, the violet is earth or ground).

But by generating alternating current it should render itself useless as a DC source? Actually no because as you know from the physics class the AC is a wave that flips between positive and negative. When we eliminate the wave from the negative side we have been left with a wave on the positive side, but the minus wave is missing. For thet we can use full wave rectifiers, they convert the minus wave to a plus wave thusby keeping the voltage wave on the one side of 0 line, and so by making AC into DC.
Posted by Jaan at 3:30 PM 0 comments