The carbon brush of the generator is also referred to as the electrical brush, as a result of its materials is "carbon", so it is usually known as "carbon brush" The function of the carbon brush is to produce the exterior power source (usually a DC excitation current) of the generator to the winding (excitation winding) of the rotor during the slip ring on the collector ring In this way, when the rotor rotates, the DC recent flowing in will keep flowing from one end of the rotor, in order that the generator rotates in a single direction The carbon brush is hooked up with the flexibility supply to provide electric energy for the rotor