ignition apparatus for igniting a combustible mixture. The German engineer Nikolaus A. Otto, in his first gas engine, used flame ignition; another method was heating a metal tube to incandescence. Ignition systems in modern automobiles use an electric spark to ignite the compressed mixture of air and gasoline in the cylinders. Battery Ignition Systems A battery ignition system has a 6- or 12-volt battery charged by an engine-driven generator to supply electricity, an ignition coil to increase the voltage, a device to interrupt current from the coil, a distributor to direct current to the correct cylinder, and a spark plug projecting into each cylinder. Current goes from the battery through the primary winding of the coil, through the interrupting device, and back to the battery. Interrupting the Current In older automobiles, the interruption of the primary current was created by "breaker points," a switch with tungsten contacts to retard erosion. Driven at half engine speed, a breaker cam, a rotating object with a lobed surface (one lobe for each cylinder), opened and closed the points. When the breaker points were closed, current flowed through the primary winding of the ignition coil. In electronic ignition systems, introduced in the early 1960s, the interrupting device is a reluctor, a magnetic pulse distributor that produces timed electric signals that are amplified to control the current to the primary winding of the ignition coil. Such systems generally reduce...
ignition apparatus for igniting a combustible mixture. The German engineer Nikolaus A. Otto, in his first gas engine, used flame ignition; another method was heating a metal tube to incandescence. Ignition systems in modern automobiles use an electric spark to ignite the compressed mixture of air and gasoline in the cylinders. Battery Ignition Systems A battery ignition system has a 6- or 12-volt battery charged by an engine-driven generator to supply electricity, an ignition coil to increase the voltage, a device to interrupt current from the coil, a distributor to direct current to the correct cylinder, and a spark plug projecting into each cylinder. Current goes from the battery through the primary winding of the coil, through the interrupting device, and back to the battery. Interrupting the Current In older automobiles, the interruption of the primary current was created by "breaker points," a switch with tungsten contacts to retard erosion. Driven at half engine speed, a breaker cam, a rotating object with a lobed surface (one lobe for each cylinder), opened and closed the points. When the breaker points were closed, current flowed through the primary winding of the ignition coil. In electronic ignition systems, introduced in the early 1960s, the interrupting device is a reluctor, a magnetic pulse distributor that produces timed electric signals that are amplified to control the current to the primary winding of the ignition coil. Such systems generally reduce...