A potentiometer is a resistive element with three leading ends and the resistance value can be adjusted according to a certain changing law. A potentiometer usually consists of a resistive body and a movable brush. When the brush moves along the resistor body, the resistance value or voltage that has a certain relationship with the displacement is obtained at the output end.

Potentiometer function:

1. Used as a voltage divider

The potentiometer is a continuously adjustable resistor. When adjusting the potentiometer's handle or slider, the moving contact slides on the resistor body. At this time, the output voltage of the potentiometer can be obtained in a certain relationship with the applied voltage of the potentiometer and the rotation angle or stroke of the movable arm.

2. Used as a varistor

When the potentiometer is used as a varistor, it should be connected as a two-terminal device, so that a smooth and continuously changing resistance value can be obtained within the stroke range of the potentiometer.

3. Used as a current controller

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

The connection method of the three pins of the potentiometer:

1. For potentiometers (or trimmer resistors, etc.) regular pins (for example, a potentiometer with 3 pins), the resistance value of both ends is fixed, and the resistance value of the middle pin to either end pin is variable of;

2. It is equivalent to dividing the potentiometer into two series resistors from the middle pin, and the total series resistance value is fixed;

3. Therefore, if it is used as a variable voltage divider resistor, one end is connected to the input voltage, the middle end is connected to the output, and the remaining end is grounded

4. If it is used as a variable resistor, one end is connected to the input voltage, the middle end is connected to the output, and the rest can be left floating, or connected to the middle end.