Ignition System: Operation

As each trigger wheel tooth approaches and passes the pole of the magnetic pick-up coil, the magnetic field created by the permanent magnet concentrates, strengthens and collapses. This induces a low-voltage alternating current in the windings of the pick-up coil.

This low voltage signal passes to the control module, which makes or breaks the primary ground circuit of the ignition coil, depending upon the polarity of the pick-up coil signal. Control module also controls the dwell angle.