Engine (such as pneumatic motors), springs (clockwork motors) and elastic bands. Historic military siege engines included large catapults, trebuchets, and (to some extent) battering rams were powered by potential energy. A pneumatic motor is a machine that converts potential energy in the form of compressed air into mechanical work. Pneumatic motors generally convert the compressed air to mechanical work though either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor. Pneumatic motors have found widespread success in the hand-held
Linear alternator Linear alternator A linear alternator is essentially a linear motor used as an electrical generator. An alternator is a type of alternating current (AC) electrical generator. The devices are often physically equivalent. The principal difference is in how they are used and which direction the energy flows. An alternator converts mechanical energy to electrical energy, whereas a motor converts electrical energy to mechanical energy. Like most electric motors and electric generators, the linear alternator works by the principle of electromagnetic induction. However, most alternators work with rotary motion, whereas "linear" alternators work with "linear" motion (i.e. motion in a straight