DC motor

A DC motor is an electric motor that turns direct current into mechanical force, most commonly through the magnetic forces produced by currents in coils. Nearly all types contain some mechanism, either electromechanical or electronic, that periodically reverses the current in part of the motor. DC motors were the first motors to be widely used, because they could run from the direct-current lighting systems already in place, and their speed can be controlled over a wide range by varying the supply voltage or the current in the field windings. Small ones drive tools, toys and appliances, while larger ones have been used to propel electric vehicles, drive elevators and hoists and run steel rolling mills, although power electronics has made replacement by AC motors possible in many uses.