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Orientation of coil in electric generator: Important?

  1. Sep 11, 2009 #1
    Hi, I'm working with my granddad on a project to build a (simple!) electricity generating windmill. We're not trying to make the most efficient design possible, just a reasonably efficient design given the simple tools and materials we're using. It's mostly just a project for fun! :)

    So, we have a setup as in the diagram below. What I'm wondering, is does it make a difference what way the coil of wire is oriented, i.e. if it is rotated 90 degrees in some direction in the design, will a greater EMF be induced in it each time it cuts the magnetic flux of the magnet.

    (To clarify, the coil is currently oriented so that additional windings will make it grow along the Y axis, looking down at the XY plane, the cross section of the coil will be circular)

    (Please go easy on me if I'm saying anything moronic, it's been a while since I studied Physics is school, and I did very little of it in college! ;) )

    (Oh, the final design will have a full radial array of coils and magnets, if that's any confusion! But my main question is what shape the coil should be !


    edit: yep, I know that should be 'propellor', not propeller!
    Last edited: Sep 11, 2009
  2. jcsd
  3. Sep 11, 2009 #2
    You have the best orientation for a windmill generator. Generally, the windmill generators have 8 to 12 magnetic poles (neodymium iron boron) in a circle, and as many coils for single phase output. But, unless you have a good way of getting the electric power off the rotor, you will want to have rotating magnets and stationary coils.

    [Edit] I am not advertising this place, but here is a good detailed discussion of an axial field permanent magnet rotor construction for windmills. You should first decide on windmill blade diameter and expected windpower (watts and RPM)) and desired alternator power output.
    http://www.otherpower.com/magnetrotors.shtml [Broken]
    Last edited by a moderator: May 4, 2017
  4. Sep 12, 2009 #3
    Hey, that's great, that cleared things up totally, and that link was full of useful detail, thanks a lot :-)

    You're right about the stationary magnets too, makes much more sense!

    Thanks :-)
  5. Sep 13, 2009 #4


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    Staff: Mentor

    In the USA, "propeller" is fine. Of course, some English-speakers claim that we Yanks speak/write a debased version of the language. :wink:
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