How does an Ignition Coil Work?

How does an Ignition Coil work? Welcome to Mercie J Auto Care, where compassion and craftsmanship come together. I'm Rick Smith, Master Certified Technician.

Well in order to have a spark plug fire, we have to have that spark jump the gap and it requires about 7,000 to 20,000 volts to jump that gap.

The problem that we have is the battery in our car this (this is obviously a small battery) but it's 12 volts. So how do we get 10,000 volts to jump a gap when we only have a 12 volt battery? Well the way we do that is with the ignition coil and the ignition coil has two sets of windings in it. One set of windings is the primary side and that's the one where we use the 12 volt battery to run current through. When we run current through, it builds up a magnetic field and then when we break that current, then that magnetic field collapses. When it does, the energy from that one coil of the one set of windings jumps into the other set and because there's a different number of windings, it increases the voltage and we get 7000 out the other side.

So ultimately at the end of the day what a coil does is it takes 12 volts and jumps it up to say 20,000. I hope that helps you understand a little bit about how a coil works and until next time safe travels and blessings to you.