HITACHI Electronic Ignition: Operation

The reluctor is mounted on the distributor rotor shaft and turns with the distributor shaft. See Figure. It is secured to the shaft with a roll pin. As the reluctor turns, its 4 external teeth come in line with 4 internal teeth of the stator. This causes the pulse generator, located inside the distributor housing, to signal the igniter (control module).

Each time the reluctor teeth come in line and then pass the teeth of the stator, transistors inside the igniter are turned off and on. This results in a magnetic field building and collapsing in the primary circuit of the ignition coil.

When the magnetic field collapses, a surge results in the secondary circuit of the coil. When this occurs, a high voltage spark is fed from the coil through the distributor's rotor and ignition cables to the individual spark plugs.