Conventional Ignition System

The basic components of the ignition system are ignition coil, distributor and spark plugs and those of the distributor are signal generator (signal rotor and pickup coil), igniter, rotor, vacuum advancer and centrifugal advancer. When the distributor shaft rotates, the magnetic flux passing through the pickup coil varies due to the change in air gap between the pickup coil and the signal rotor. As a result, an alternating current and voltage is induced in the pickup coil.

The voltage induced, cycles the igniter "ON" and "OFF" which switches the ignition coil primary current "ON" and "OFF." Thus, when the primary current is "OFF," high voltage is induced in the secondary winding of the ignition coil and ignition voltage is generated at the spark plugs. The spark advance is produced by the vacuum advance and the centrifugal advance.