The stationary brushes, which are graphite connectors on the generator, form contact with opposite parts of the commutator. As the armature coil turns, it cuts across the magnetic field, and current is induced. By doing this, the brushes keep current going in one direction, and deliver it to and from its destination. Direct Current Motors Motors change electric energy into mechanical energy. Direct current motors and generators are constructed very similarly.
Simple motors have a flat coil that carries current that rotates in a magnetic field.
The motor acts as a generator since after starting, it produces an opposing current by rotating in a magnetic field, which in turn results in physical motion. This is accomplished as a conductor is passed through a magnetic field, then the opposing fields repel each other to cause physical motion. The pointer finger points in the direction of the magnetic field, the middle finger points in the direction of the current, and the thumb shows which way the conductor will be forced to move. A self-excited motor produces its own field excitation. A shunt motor has its field in parallel with the armature circuit, and a series motor is when the field is in a series with the armature.