Ignition Coil: Description and Operation

Fig. 34 Power Transistor and Ignition Coil:

PURPOSE
Increases battery voltage to a level necessary to ignite the combustion mixture.

LOCATION
On left fender apron.

OPERATION and CONSTRUCTION
The Ignition Coil uses 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 one ignition coil.