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Transformer ? and current

  1. Mar 22, 2010 #1
    like in a car when electrons flow through the battery to the coil , the coil is like a transformer using coiled copper wire to up the voltage to give the spark plugs a hotter spark. I am not sure where this energy is coming from , so are we actually getting more electrons to flow per second and after it goes through the coil . does the coil allow it to draw more current from the battery.
  2. jcsd
  3. Mar 23, 2010 #2


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    Basically, all that matters is that total energy is conserved so energy per secons is :

    P=U*I so P is a constant in a transformer ( at least consider it so)

    If so then IF p=5W there are an infinity of possibilities for U and I. Like U=5 I =1 or I=5 U=1 etc.

    That is what happens in a transformer, energy is the same it is just expressed differently.

    For different ways transformers can be made consult wikipedia.

    I"ve made the exemple in direct current for easy understanding :P
  4. Mar 23, 2010 #3


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    Staff: Mentor

    You have the wrong idea about what a transformer does: A transformer keeps the energy constant while increasing the voltage, which means fewer electrons per second going through the secondary side than the primary side.
  5. Mar 23, 2010 #4
    i see thanks for your answers
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