Ignition Coil: Description and Operation

The Ignition Coil pack consisting of 2 coils, uses the principle of mutual induction to step up battery (low) voltage to ignition (high) voltage. The Ignition Coil contains two windings of copper wire around a soft iron core. The primary winding is made of approximately hundred turns of a heavy gauge wire. It is connected to the battery through the ignition switch. Current flows through it creating a magnetic field. When current flow in the primary winding is stopped (by the power transistor breaking the circuit ground), the collapse of the magnetic field causes a voltage to be induced in the secondary windings. The ratio of turns in the primary windings to the number of turns in the secondary windings determines the voltage step up.