Which component provides the spark plug with a high voltage pulse in a spark ignition engine?

In a spark ignition engine, the high voltage pulse sent to the spark plug is generated by the ignition coil. The ignition coil transforms the low voltage from the battery into a much higher voltage needed to create a spark at the spark plug, which ignites the air-fuel mixture in the engine cylinder.

While the battery initially provides the necessary power to start the ignition process, it is the ignition coil that is responsible for creating the high voltage required for the spark plug to ignite the mixture. The distributor's role is to direct the high voltage pulse from the ignition coil to the correct spark plug at the appropriate time, but it does not generate the voltage itself. The alternator, on the other hand, generates electricity to recharge the battery and power electrical systems while the engine runs but does not play a direct role in the ignition process.

Understanding the function of the ignition coil is crucial, as it operates by using electromagnetic induction to produce the needed high voltage when the current supply to the coil is turned off, allowing the spark to occur at the spark plug. This mechanism is fundamental in the functioning of spark ignition engines.