Ignition Coil: Description and Operation

Fig. 34 Power Transistor and Ignition Coil:

The Ignition Coils (2), located on the left side of the engine compartment below the intake air boot, use the principle of mutual induction to step up battery (low) voltage to ignition (high) voltage. The Ignition Coil contains two sets of copper wire windings around a soft iron core. The primary winding is made of a hundred or so turns of a heavy gage wire. It is connected to the battery (through the ignition switch) so that current flows through it, thus creating a magnetic field. When current flow in the primary winding is stopped (by the power transistor), 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 multiplication. This system utilizes two ignition coils.