## transformer ? and current

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.
 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

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 Quote by cragar 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.
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.