Potentiometer is a resistance element with three leads and the resistance value can be adjusted according to a certain change law. Potentiometers usually consist of a resistor and a movable brush. When the brush moves along the resistance body, the resistance value or voltage related to the displacement is obtained at the output end. The main functions of potentiometer in the circuit are as follows.

1. Used as voltage divider

The potentiometer is a continuously adjustable resistor. When the rotating handle or sliding handle of the potentiometer is adjusted, the moving contact slides on the resistor body. At this time, the output voltage that is related to the applied voltage of the potentiometer and the angle or stroke of the movable arm can be obtained at the output end of the potentiometer.

2. Used as rheostat

When the potentiometer is used as a rheostat, it should be connected into devices at both ends, so that a smooth and continuously changing resistance value can be obtained within the stroke range of the flower potentiometer.

3. Used as current controller

When the potentiometer is used as a current controller, one of the selected current output terminals must be the sliding contact lead out terminal.