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Ignition Coil

Ignition Coil — What is it and how does it work?

An ignition coil provides a high voltage pulse which creates the energy for a spark to jump the spark plug gap and initiate the combustion process in the cylinder. The ignition coil has three components; primary winding, secondary winding, and an iron core. These components work together to convert 12-volt DC power in 25,000 to 40,000 volts DC.

Primary windings and the iron core

The primary winding consists of hundreds of wraps of Ignition coil a thicker gauge wire that is wound around an iron core. When 12 volts are applied to the primary windings, the two windings induce a magnetic field, basically turning the unit into a powerful electro-magnet.

Secondary windings

The secondary windings consist of thousands or wraps of small gauge wire wound around the primary windings and iron core.

How the ignition coil works

The primary windings and iron core create a strong electro-magnet. When power or ground is disconnected from the primary windings from either the ignition module or the ECM, the strong magnetic field collapses. During the collapse, the collapsing magnetic energy induces a surge of current in the secondary windings. So an ignition coil takes electricity and converts it into a magnetic field and then back to electricity. However, since the secondary coil contains so many more windings, the magnetic field collapse transforms 12 volts into 25,000 to 40,000 volts. The amount of the increase in voltage is directly proportional to the ratio of primary to secondary windings, which is typically around 80.

See this post for information on bad ignition coil symptoms

See this post for information on how to test an ignition coil

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Posted on by Rick Muscoplat


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