Electronic Ignition: Operation: Distributor
The distributor has a toothed wheel, called a reluctor, instead of the conventional cam. It has one tooth for each of the engine's 6 cylinders. Normal breaker points are replaced by a dual pick-up coil assembly, composed of 2 fine wire coils, magnets, and pole pieces. See Fig 1.
During cranking, current flows to the distributor through the start pick-up circuit of the dual pick-up start-run relay. Once the engine begins to run, the relay switches back to the run pick-up circuit. A weak magnetic field is created around the "live" pick-up coil.
As the distributor shaft turns, the reluctor teeth pass the "live" pick-up coil assembly (only one pick-up coil operates at a time), interrupting the magnetic field and creating an electronic signal. This signal is transmitted to the control unit, which shuts off current to the primary circuit of the ignition coil.
As no moving parts contact each other in the distributor, there is no wear and therefore no need for regular adjustment.