Who I am ---------- Disclaimer Automotive glossary Capacitor Discharge Ignition Synonym: Thyristor Ignition Abbreviation: CDI | Definition Capacitor Discharge Ignition: Engendering the ignition spark is with this one done by the battery. The battery voltage is hereby transformed to beyond 300 volts and a capacitor is being charged by it. Via a semiconductor switch, the socalled "thyristor", the capacitor is then being discharged suddenly into the ignition coil, and thus produces the required high voltage impact on the other side of the ignition coil.![]() All definitions |