Ignition System - HITACHI Electronic: Operation
The reluctor turns with the distributor shaft. It is secured to the distributor rotor shaft by a roll pin. As the reluctor turns, its 4 external teeth come in line with the 2 stator upright teeth.
As the reluctor approaches and passes the stator teeth, variations occur in the magnetic field around them. Each time the reluctor teeth come in line with and then pass the stator teeth, transistors inside the ignitor are turned off and on.
This results in a magnetic field building and collapsing in the primary circuit of the ignition coil. When this field collapses, a voltage surge occurs in the secondary circuit of the ignition coil. When this occurs, a high voltage spark is fed from the coil, through the distributor rotor and cap to the secondary wiring and spark plugs.