Ignition System: Description and Operation

Fig. 1 Exploded view of solid state ignition system:

Fig. 2 Schematic view of solid state ignition system:

The principle components of a solid state ignition system are the spark plugs, ignition coil and distributor. The distributor, Fig. 1, has a rotor, module, pole piece, vacuum advance and a centrifugal advance.
The pickup coil is used to generate the ignition signal and consists of a pole piece, magnet and a pickup coil. The pole piece is attached to the distributor shaft. The magnet along with the pickup coil, is attached to the pickup coil base plate.
When the distributor shaft rotates, the magnetic flux passing through the pickup coil varies due to the change in the air gap between the pickup coil and the pole piece. As a result, the alternating current voltage is induced in the pickup coil. The voltage induced, turns the module off and on which switches off the ignition coil primary current. Thus the high voltage is induced in the secondary winding of the ignition coil and ignition sparks are generated at the plugs, Fig. 2.