Coils

Discussion in 'The Projects Forum' started by floomdoggle, Jan 6, 2009.

  1. floomdoggle

    Thread Starter Senior Member

    Sep 1, 2008
    217
    2
    Hey everybody,
    I've built my first windmill. Thanks to AAC, it works!
    Now I would like to build my next windmill, constructing my own generator.
    My question is, how would be the best way to hook-up the coils? I know about star and delta. What I am wondering about is, since there is not a whole lot of info on straight series or parallel wiring, would it not be just as well to wire the whole thing in parallel? It would seem to give less ripple after it is rectified. But would power suffer?
    Twelve magnets, nine coils. Coils are 40 turns of 20AWG.
    As always, than you in advance.
    Dan
     
  2. duffy

    Active Member

    Dec 29, 2008
    44
    0
    "the whole thing"? What, all 9 coils in parallel? That probably wouldn't be a good idea. Can you post a link for the layout of the coils and magnets?
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Congrats on the windmill working :)

    Check out this steam-powered generator: http://www.youtube.com/watch?v=fykeQNVadYk
    The build details: http://www.otherpower.com/steamengine.shtml
    but they didn't give details on the wiring of the rectification scheme!

    As far as wiring them all up in parallel - you'll likely get nothing out of it. That's because the magnets will be passing by the coils at different times; thus every coil will be at a different electrical potential.

    You need to construct a multiphase bridge rectifier, or a synchronous bridge rectifier (better efficiency).
    [eta]
    If you want to keep it simple, you could connect the coils in a star topology; then use one fullwave bridge rectifier per two coils to connect them to the + and - rails, like this:
    [​IMG]
     
    Last edited: Jan 7, 2009
  4. floomdoggle

    Thread Starter Senior Member

    Sep 1, 2008
    217
    2
    Hey Duffy.
    Why not nine coils in parallel? I ask because I do not know.

    Hey Sarge,
    Thank you for the input. I'll check out those multi-phase rectifiers.
    I had seen that steam engine before, wish I lived where I had enough wood to use it. I'll stick to wind for the moment.
    Also, is there a way to switch between star and delta? I had heard about a sensor on a needle meter, but that sounded iffy. Maybe an anemometer sensor? As always, thank you.
    Dan
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I don't understand why you'd want to switch between star and delta topologies.

    Actually, if you're really careful with the placements of your coils and magnets, you'll wind up with a 3-phase output. You could connect all coils together in a star topology, and then coils 1, 4, and 7 would be phase A, 2, 5, and 8 phase B, etc. That way you could use a single 3-phase bridge rectifier out of an alternator.

    You're not going to be getting much power out of your coils. 40 turns of AWG 20 is pretty weak.
     
  6. floomdoggle

    Thread Starter Senior Member

    Sep 1, 2008
    217
    2
    Hey Sarge,
    Changing star to delta is something I just read. Don't know if it would work.Star at slow speed, delta at fast speed. Would also correct some drag problems on the generator. Not much, but maybe enough to increase efficiency by 10 %. @ higher speeds. Unless I got star and delta backwards.
    Yes I know 40 turns of 20 AWG may not produce much. At low speeds, say 200 rpm, it seems very efficient. At least that is what I read. I'll let you know how it works.
    As always thank you.
    Dan
     
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