What is a potentiometer a device used to?

 A potentiometer is a tool for manually adjusting the electrical resistance of a circuit. It is comprised of a resistive element with three terminals, one each for the resistive track's ends and the wiper, a moveable contact. The resistance between the wiper and either end terminal can be changed by shifting the wiper's location along the resistive track. A potentiometer can regulate multiple electrical characteristics in a circuit, including voltage, current, and signal level, thanks to its resistance fluctuation. Potentiometers are frequently employed in electronic circuits for functions including bias or gain level setting, brightness adjustment, speed control, and volume control.

Do potentiometers control voltage or current?

Potentiometers can be used to control either voltage or current, depending on how they are connected in a circuit and the specific application.

Controlling Voltage: When a potentiometer is connected as a voltage divider, with one end connected to a fixed voltage source (e.g., Vcc) and the other end connected to ground (GND), the voltage output from the wiper (the movable contact) can be varied by adjusting the position of the wiper along the resistive track. In this configuration, the potentiometer controls the voltage output between the wiper and one of the end terminals.

Controlling Current: Potentiometers can also be used to control current indirectly. For example, in a circuit where the potentiometer is used to adjust the bias or gain level of a transistor amplifier, the variation in resistance introduced by the potentiometer affects the biasing conditions of the transistor, which in turn affects the collector current. Similarly, in a circuit where the potentiometer is used to adjust the speed of a motor, the variation in resistance affects the voltage supplied to the motor, which in turn affects the current flowing through it.

Therefore, even though potentiometers are often used to control voltage, in some situations they can also be used to control current indirectly by modifying factors like voltage levels or biasing conditions that have an impact on current flow.