Toyodenso

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 pick-up coil is located inside the distributor and utilizes an external igniter assembly located on the side of the distributor.