2. Charging System This is the heart of the electrical system. It consists of three main components: the belt-driven alternator, various electrical circuits, and a voltage regulator. The alternator supplies power to the electrical system and recharges the battery after your car has started. Just like it sounds, the voltage regulator controls the voltage, keeping it within the operating range of the electrical system.
A fitter checking the ignition system of the Napier Sabre engine used by the Hawker Typhoon. These 2,200hp engines had 48 spark plugs and remained rather tempremental throughout it's service - World War 2