Ignition Control Module: Description and Operation

Ignition Coil With Power Stage:

The Power Stage is the device which controls primary current supply to the ignition coil. It is combined with the ignition coil and consists of a power transistor and integrated circuit.

The Power Stage receives a triggering signal from the Digifant I control unit. The voltage signal (trigger) to the power stage turns it "ON". In this "ON" state, current flows through the primary circuit of the ignition coil. When the Digifant control unit determines that it is time for coil discharge, the current to the power stage is momentarily interrupted and the transistor turns "OFF". This interrupts primary current flow to the coil creating a high voltage discharge in the secondary circuit of the coil. In this manner, the power stage operates like a solid state pair of ignition points.