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Electromagnet construction questions

  1. Mar 29, 2008 #1
    I need a bit of help in constructing 2 small electromagnets with opposite poles for quickly moving a 4 or 8lb pull rare-earth magnet back and forth ~ 3 cm, farther if need be.
    _______ _______ ________
    |e-mag 1|-----|r.e.mag|-----|e-mag 2| ("---" being a rail)

    (sry for my bad attempt at a visual)

    My only real constraint is that I need it to run off a couple AA/AAA or 9v batteries, though I would prefer to keep things around 1.5" in diameter.

    I guess my most important questions would be:

    1) What material wire should I use to wind the cores? (I have a lot of copper, 99.9% Ag, and various other wire in 18-20 guage)

    2) What size wire should I be using?

    3) What is the possibility of switching the polarity of the magnets quickly?

    Sorry if my request is slightly strange, but I've been tinkering around for a couple weeks, reading various forums and am still getting nowhere fast. Each magnet I've made (about 20) won't repel the rare-earth magnet at all from the ferrite core i've been using and the dead batteries are starting to pile up. :grin:

    If all else fails, does anybody know where I might be able to purchase a suitable electromagnet or what I can rip something similar out of?

    Thanks for any help you might give me at all.

  2. jcsd
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