Ignition Coil: Description and Operation

PURPOSE
The Ignition Coil transforms battery voltage into secondary ignition voltage and delivers it in the form of a high voltage surge to the secondary ignition components. This ignition system uses two ignition coils, one for each cylinder bank.

OPERATION
The ignition coil contains two windings of copper wire around a soft iron core. The primary windings are made of a hundred or so turns of wire. The secondary windings contain several thousand turns of wire wound directly onto the iron core. The ratio of the number of wraps in the secondary winding to the number of wraps in the primary windings determines the output voltage of the coil. Current flow through the primary winding is stored as a magnetic field. When current flow in the primary winding is interrupted (by the power transistor breaking the circuit ground), the magnetic field collapses, inducing a voltage surge into the secondary windings.