In a typical ignition system, the spark plug is part of which circuit?

The spark plug is an essential component found in the secondary circuit of a typical ignition system. In this system, the primary circuit consists of lower voltage components, such as the ignition coil's primary winding, which operates at a voltage less than that required to create a spark. Once the ignition coil generates a magnetic field and the current through the primary winding is interrupted, the coil induces a high voltage in the secondary winding.

The secondary circuit is responsible for transporting this high voltage to the spark plug, enabling it to generate a spark sufficient to ignite the air-fuel mixture inside the engine's combustion chamber. It is this high voltage that travels from the ignition coil to the spark plug, allowing for efficient combustion and powering the engine.

The distinction between the primary and secondary circuits is crucial, as it highlights how the ignition system operates and the role each component plays in engine functionality. Understanding this relationship helps in diagnosing and troubleshooting ignition system issues in four-stroke engines effectively.