A potentiometer is an adjustable resistor that can change the output voltage and current of a circuit by adjusting its shaft. In actual circuits, potentiometers can be connected as a variable resistor or a voltage divider. In addition to the nominal value (E6 series), rated power, and tolerance of a resistor, potentiometers also have a law of resistance change. This law refers to the relationship between the rotation angle of the shaft and the change in resistance value. Selection of potentiometer types: 1. In circuits with low requirements, carbon film potentiometers can be used. 2. For precise adjustments and higher power consumption, wire-wound potentiometers should be selected. 3. In circuits with high operating frequencies, glass-glazed potentiometers are preferable.