A potentiometer is essentially a variable resistor. Because its role in a circuit is to obtain an output voltage that has a certain relationship with the input voltage (applied voltage), it is called a potentiometer. As shown in the schematic diagram below, a potentiometer (or trimmer, etc.) typically has three pins. The resistance between the two outer pins is fixed, while the resistance between the middle pin and either outer pin is variable. It is generally designed to maintain its characteristics regardless of how long it is used. When used as a position sensor, a potentiometer can be a linear or rotary position sensor. The potentiometer outputs a voltage value that is proportional to the position of the slider along the variable resistor. However, temperature changes, wear, and dirt between the slider and the variable resistor can cause resistance changes, affecting the accuracy of the potentiometer.

Schematic Diagram