What is the function of an ignition coil in automotive applications?

The ignition coil serves a crucial role in the ignition system of an internal combustion engine. Its primary function is to transform the low voltage from the battery, typically around 12 volts, into a much higher voltage, often reaching up to 45,000 volts or more. This high voltage is necessary to create a spark at the spark plugs, which ignites the air-fuel mixture in the engine’s cylinders.

This transformation occurs through electromagnetic induction. The ignition coil consists of two windings: the primary and secondary winding. When a potential difference is applied, an electric current flows through the primary winding, creating a magnetic field. Once the current is interrupted (usually by the ignition control module or points), the collapsing magnetic field induces a high voltage in the secondary winding. This high voltage is then sent to the spark plugs, allowing for ignition of the fuel-air mixture.

The other functions listed do not pertain to the role of an ignition coil. Regulating battery charge is typically managed by the alternator and voltage regulator. Storing electrical energy is a characteristic of batteries and capacitors, not ignition coils. Measuring electrical resistance is the function of ohmmeters and multimeters, not ignition coils, which focus instead on voltage conversion for spark generation.