Ignition System - LUCAS Electronic: Operation

As the distributor shaft turns, the reluctor turns with it. As each of the 6 or 12 teeth approach and pass the pick-up coil's pole piece, the strength of the magnetic field around it will vary. This creates a voltage in the winding of the pick-up coil.

The rise and fall of this voltage is sensed by the amplifier module, which then sends a signal, cutting off voltage to the primary circuit of the ignition coil. This causes a voltage surge in the secondary, firing the spark plugs at the proper time.