Ignition System Basics

All ignition systems comprise the following components or functions:

1. A battery to supply the initial voltage (usually 12 volts) to the coil

2. An ignition coil to generate the much higher voltage that is needed to ignite the air/fuel mixture.

In simple terms, this is an electrical transformer with two windings on a magnetic core

3. A distributor (or an electronic device that provides the same services), which handles two tasks: Triggering the coil to release its electrical current, and distributing this strong electrical current from the coil to each spark plug at the appropriate time

4. A spark plug for each cylinder, which applies the electrical current from the coil to the gap between its electrodes in order to generate a strong enough spark to ignite the air/fuel mixture in the cylinder

Some types of ignition systems have additional hardware. Some have multiple ignition coils. The most sophisticated ignition systems delete the distributor entirely, and instead rely on signals from an Engine Control Unit (ECU) to determine ignition timing.

In every case, however, the electrical energy that starts as very low voltage is increased dramatically by the coil to create the spark that arcs across the gap that ignites the air/fuel mixture.

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