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Electromagnet pulse coil powered by static charge

  1. Apr 29, 2004 #1
    Hello, I have a question concerning electromagnet coils and static electricity. If one were to generate a static charge and store it up some how (like in a Leyden jar or something), and that charge was then dumped over a small electromagnet, would there be enough energy to provide a small electromagnetic pulse from that coil? I know I am probably not providing enough information here but my idea is to use two spinning disks spinning close together to build up a static charge and store it into a Leyden jar. Then I want to use that charge to momentarily pulse a small coil, which in turn would repel a small magnet hanging from a string. Do electromagnet coils need a high wattage in order to produce a good powerful spark, or would a high voltage at low amps be sufficient? Also, what kind of wire would be appropriate for something like this?

    Thanks,
    Jason O
     
  2. jcsd
  3. Jun 22, 2005 #2
    Hi

    you could do this with a capacitor, store up all the energy you needed by connecting it across a pc computer 5v power supply to charge it, then connecting the electromagnet, like a speaker, across it.

    you could use transistors for switches controlled by some other voltage, but it would move a magnet hanging on a string

    the capacitor value? the highest farad rating possible, and the voltage is whatever volts you work with, but guess high.

    electromagnets work on current, the leyden jar is a voltage storing device unless Im mistaken, of course there is volts/current but moving motors takes more current than most other things take. converting across? only if you have to.

    spinning disks? if you need to have the disks this would work as you described



     
  4. Jun 22, 2005 #3

    Cliff_J

    User Avatar
    Science Advisor

    The electro magnet works off the number of coils and amount of current per coil. If you're winding your own coil you'll likely want to find some enameled wire of the smallest gauge possible to maximize the number of turns and wind them as tighly and neatly (could be with a drill) on a steel core of some kind. I'm also picturing a very small magnet moving a very small amount on this string next to this coil.

    A static charge is very high volts and very low current due to the poor conductors involved. If the voltage was not very high it would not be able to overcome the high resistance of the poor conductors. Something like a capacitor for a camera flash would be a cheap thing to try to store the charge in, and I'd guess it'd take a while to generate sufficient amounts of charge for even that.

    You'd have a far easier time trying to generate electrical power by spining a magnet across some coils of wire but maybe that's outside what you're trying to do.... Or even better a classic example like two ballons on a string rubbed against a wall and watch the like charges repel each other. But maybe those are too easy... :smile:
     
  5. Jun 22, 2005 #4
    charging up a Flash Capacitor to 5V or even 12V is a good idea , , i also liked the idea of using a speaker coil..
    But using a transistor will just waste power, besides a switch will suffice..or just touch the wires together..
     
  6. Jun 28, 2005 #5
    Hello,

    Thank you all for the help. Yes, my major concern was understanding if the two disks spinning past each other would actually build up sufficient charge to pulse the coil. And I'm still not sure if this will work as far as the disks go. Just to clarify, the idea here is that the static charge builds up on the disks from them spinning very close to each other, but they don't ever make contact with each other and there are no brushes to rub them against each other. Before I can shell out the rest of the idea, I need to know if this part is even doable.

    - Jason O
     
  7. Jul 29, 2008 #6
    A coil sparks at disruption of a current.
    I don't see how charge and coils are comparable electrically.
    The coil property is to CONTINUE current flow.
    Thus a coil makes an instantaneous voltage spike to breakdown air at the disconnect.

    What I have seen done with a coil and charge:
    A static charge from rubbing wool on a plate with insulated handle
    induced a charge into a conical coil.
    The coil self resonated and the teacher demonstrated how the whole
    class holding hands felt a tingle of electricity.
    Something less than 28v bell wire AC or from a model train transformer.

    So the charge was small and generated high voltage AC.

    What I hear supposed about coils and charge:
    That a conical coil induced with AC will generate charges.

    A magnet from a string might not react but a coil might if the charge
    induction into a resonant circuit works.
    This sounds like some idea to power a car with a static generator.
     
  8. Feb 8, 2012 #7
    if you want this to work, build it by this formula Hp = 1/2(p-eac)+edc
     
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