A DC motor is an electric motor that runs on direct current (DC) electricity. Every DC motor has six basic parts — axle, rotor (a.k.a., armature), stator, commutator, field magnet(s), and brushes. The geometry of the brushes, commutator contacts, and rotor windings are such that when power is applied, the polarities of the energized winding and the stator magnet(s) are misaligned, and the rotor will rotate until it is almost aligned with the stator’s field magnets. As the rotor reaches alignment, the brushes move to the next commutator contacts, and energize the next winding.
The following circuit diagram uses solid state switching (transistors) to control direction of a DC motor. This circuit was built to operate a small motor used for opening and closing a pair of curtains. This circuit allows manual control of the motor (and for curtain control) allows precise amounts of light into a room. Get more info of Circuit Diagram for DC Motor Control by A. Collins here – source: zen22142.zen.co.uk.