The bulk of the electric starter is a relatively simple 12-volt (or six-volt) electric motor. Connected to that motor are the two parts that make it a starter: the pinion gear and the bendix assembly. When the electric starter is activated, either via a key switch or a floor-mounted switch, the starter bendix senses the armature momentum and forces the pinion gear to extend into the teeth around the circumference of the flywheel. Once the engine has started and the ignition key has been released, the bendix loses momentum and the bendix is forced to return to idle position.The electric starter is contained within a heavy-duty starter housing, which is designed to withstand the forces generated by the starter motor turning the engine through its cycle. The housing also contains the armature magnets, which surround the armature assembly including the starter windings, and a brush set that is used to contact the armature to transfer electrical energy.