A potentiometer is a variable resistor that moves across a resistance with a moving contact to obtain a voltage output.

It is used as a voltage divider, a rheostat, and a current controller. The designers can follow the following principles when designing potentiometers:

1. Power type wire-wound potentiometer is selected for high-power circuit;

2. The tone control of the sound system can choose direct sliding potentiometer;

3. The reference voltage of the power supply circuit shall be adjusted by using a fine-tuning potentiometer;

4. The potentiometers used in communication equipment and computers may be SMT multicoil potentiometers or single-coil potentiometers;

5. Small carbon film potentiometer with rotary switch can be used for volume adjustment and power switch of semiconductor radio;

6. High-precision wire-wound potentiometer, precision multi-turn potentiometer or metal-glass glaze potentiometer should be selected in the circuits of precision instruments;

7. When selecting a potentiometer, the material, structure, type, specification and adjustment mode of the resistance body of the potentiometer shall be selected according to the specific requirements of the applied circuit;

8. Audio equipment in the tone control potentiometer should choose the inverted logarithmic (old exponential) potentiometer, volume control potentiometer can choose logarithmic potentiometer;

9. After selecting the type and specification of potentiometer according to the requirements of equipment and circuit, the electrical parameters of potentiometer shall be reasonably selected according to the requirements of circuit, including rated power, nominal resistance, allowable deviation, resolution, maximum working voltage and dynamic noise, etc..