Potentiometer

_images/potentiometer.png

Potentiometer is also a resistance component with 3 terminals and its resistance value can be adjusted according to some regular variation.

Potentiometers come in various shapes, sizes, and values, but they all have the following things in common:

  • They have three terminals (or connection points).

  • They have a knob, screw, or slider that can be moved to vary the resistance between the middle terminal and either one of the outer terminals.

  • The resistance between the middle terminal and either one of the outer terminals varies from 0 Ω to the maximum resistance of the pot as the knob, screw, or slider is moved.

Here is the circuit symbol of potentiometer.

_images/potentiometer_symbol.png

The functions of the potentiometer in the circuit are as follows:

  1. Serving as a voltage divider

    Potentiometer is a continuously adjustable resistor. When you adjust the shaft or sliding handle of the potentiometer, the movable contact will slide on the resistor. At this point, a voltage can be output depending on the voltage applied onto the potentiometer and the angle the movable arm has rotated to or the travel it has made.

  2. Serving as a rheostat

    When the potentiometer is used as a rheostat, connect the middle pin and one of the other 2 pins in the circuit. Thus you can get a smoothly and continuously changed resistance value within the travel of the moving contact.

  3. Serving as a current controller

    When the potentiometer acts as a current controller, the sliding contact terminal must be connected as one of the output terminals.

If you want to know more about potentiometer, refer to: Potentiometer - Wikipedia

Example