Potentiometer composition material:
        A potentiometer is a resistance element with three leading ends, which can be adjusted according to some change of resistance. A potentiometer is usually made up of a resistor body and a movable brush. When the brush moves along the resistor, the resistance or voltage at which the displacement is related is obtained at the output.

Potentiometer can be used as three terminal component, also can be used as two terminal component. The latter can be considered as a variable resistor, because it is in the circuit role is to obtain and input voltage (external voltage) is related to the output voltage, so called potentiometer.

　    It's actually a variable resistor, but very few of them are used when a variable resistor is used.

　    There are three points in the two end with a certain potential difference, different potential sliding contact is in a different position, can cooperate with other components of various circuit, this is the main purpose.

　    There are different resistance and power, such as carbon film and wire winding structure.