Question

Which component in a capacitor discharge ignition (CDI) system is responsible for providing the precise timing signal to the power pack?

Accepted Answer

The component responsible for providing the precise timing signal to the power pack in a capacitor discharge ignition system is the trigger coil, often referred to as the pickup coil or pulser coil. The trigger coil is a small electromagnetic sensor positioned near the rotating flywheel of the engine. The flywheel contains a raised metal protrusion called a trigger tab or magnet insert. As the engine rotates, this metal tab passes directly in front of the trigger coil, which disrupts the coil&#x27;s magnetic field. This disruption induces a small, precise voltage pulse within the trigger coil wires. This specific pulse is sent to the power pack, which acts as an electronic switch. Upon receiving this electrical signal, the power pack triggers the discharge of stored electrical energy from its internal capacitor into the ignition coil to create a spark at the spark plug. Because the trigger coil is physically mounted in a fixed position relative to the rotating engine components, it ensures that the spark occurs at the exact moment required for efficient engine combustion.

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Which component in a capacitor discharge ignition (CDI) system is responsible for providing the precise timing signal to the power pack?