Hitachi

The rotating reluctor produces a voltage pulse in the pick-up coil each time a spark plug is to be fired. The pulse transmitts through the pick-up coil, to the power transistor inside the igniter assembly, causing the transistor to interrupt current flow in the primary circuit. This interruption in the primary circuit induces high voltage in the secondary coil and fires a spark plug. The igniter/pick-up coil assembly is incorporated into a single unit located inside the distributor.