coilanddistributor

The coil and distributor is a key component of older internal combustion engines, specifically those that use a spark ignition system. This system's primary function is to deliver a high-voltage electrical spark to the correct spark plug at the precise moment needed for combustion. The distributor, often a rotating component with a cap and rotor, is responsible for routing the high voltage from the ignition coil to each spark plug in the firing order. Inside the distributor, points and a condenser (or an electronic equivalent) interrupt the flow of current to the ignition coil, creating a high-voltage surge.

The ignition coil itself is a transformer. It receives low voltage from the vehicle's battery and transforms it into the high voltage necessary to jump the gap of a spark plug. When the points in the distributor open, they break the primary circuit of the coil, causing the magnetic field to collapse. This rapid collapse induces a high-voltage current in the secondary winding of the coil. This high voltage is then sent through a spark plug wire to the distributor's cap, where the rotor directs it to the appropriate terminal, and subsequently to the correct spark plug for ignition.

Modern vehicles have largely replaced the mechanical coil and distributor system with electronic ignition systems, such as distributorless ignition systems (DIS) or coil-on-plug (COP) systems. These newer technologies offer greater precision, reliability, and require less maintenance, eliminating the need for mechanical components like points and rotors that wear out over time. However, the fundamental principle of transforming low voltage to high voltage to create a spark remains the same.