In the traditional pin of potentiometer (or trimming resistor, etc.). ), the resistance values at both ends are relatively fixed, and the resistance values from the middle pin to any end pin are variable. It is equivalent to dividing the potentiometer into two series resistors from the middle pin, and the total series resistance is fixed.
Therefore, if it is used as a variable voltage divider, one end is connected to the input voltage, the middle end is connected to the output, and the remaining lower end is grounded. If used as a variable resistor, one end is connected to the input voltage, the middle end is connected to the output, and the remaining lower end can be suspended or connected to the middle end.
Extended data
Potentiometer is a resistance element with three terminals, and its resistance value can be adjusted according to a certain change law. Potentiometers usually consist of resistors and movable brushes. When the brush moves along the resistor, the resistance value or voltage related to the displacement is obtained at the output end.
Potentiometers can be used as both three-terminal elements and two-terminal elements. The latter can be regarded as a variable resistor, because its function in the circuit is to obtain an output voltage that has a certain relationship with the input voltage (applied voltage), so it is called a potentiometer.
References:
Baidu encyclopedia-potentiometer