Starter, device that causes the crankshaft in an engine to turn and operate. Different kinds of engines require different kinds of starters. For example, the starter in an automobile receives electric current from the battery, which, in turn, starts the starter motor: This rotates the crankshaft and ignites the spark plugs in the engine. Diesel-powered engines, including those found on many railroad cars, sometimes inject compressed air into cylinders that start the engine. The air turbine starters or jet turbine starters on airplanes use high-pressure air to start the engine; a separate device on the aircraft or ground—the auxiliary power unit (APU)—ignites the starter.
See also: Kettering, Charles Franklin.