Quick OverviewTwo Sides to Every IgnitionThe Primary SideThe Secondary SideIgnition MaintenanceA typical (meaning stock) 12-volt automotive ignition system operates by taking in a low voltage with high current from the car''s battery and changing it into a higher voltage with lower current to jump the spark plug gap to propagate combustion in the cylinder. This process of changing low voltage to high voltage, called induction, takes place inSee more on holley EDN[PDF]
AN-8208 Introduction to Automotive Ignition Systems - EDN
Basically, a CDI system consists of a charging circuit, a triggering circuit, an ignition coil, a spark plug, and the energy storage unit (main capacitor). The input source supplies 250-600 V for the CDI