|Using car alternator rectifiers.
If you have an old car alternator sitting
there doing nothing, you can use its rectifier for your
windmill. These rectifiers are a 3 phase heavy duty
unit, and designed to work under extream conditions.
The following is how to use a rectifier
from a Fiat alternator. Why a Fiat, well they are a
bit of a natural resource around here, the owner of
the property I'm renting has a thing for them and there
are hundreds of old Fiat cars here, seriously.
But the same princible applies to just
about any alternator, they all look different and the
rectifiers are all sorts of shapes and sizes, but they
have in common...
- 3 input leads. 3 phase AC in.
- 2 output leads. DC out.
Le alternator, all the way from
Undo the long screws that hold
the thing together, dont worry about removing
the pully. The pully end and armature will slide
out, maybe with the help of a big hammer.
|If you look into the
depths you will see 3 thick wire from the stator
connected to the rectifier.
|Remove the rectifier
from the case ( it may slide out from the back ).
You will have to undo some screws and the output
power terminal. Just keep unbolting stuff untill
you can get it out. Cut or unsolder the 3 stator
wires. These 3 terminals will be connected to the
3 phase output of our windmill.
|If you look at this
rectifier ( and just about all follow this same
rule ) you will see two plates, each with 3 diodes
connected. One of the plates is positive and the
other is negative. The negative is the plate that
was eathed to the alternator case, and the possitive
is the plate that was insulated from the casing
and connected to the output terminal. But if the
alternator is from some weird european car that
has a possitive earth, then everything I said above
is reversed, I think.
Using 3 bridge rectifiers.
Dick Smith sell a cheap 35amp
bridge rectifier that can be used as a 3 phase
rectifier. You need 3 bridges, and wire them as
shown below. Be aware that sometimes these bridges
are labled incorrectly, always use a multimeter
to check the connections. The one shown here is
correct, the + sysbol lines up with the tag at
right angles to the others. I have seen some where
the + and AC is printed on the other side.
© TheBackShed 2011