A variable resistor is a type of resistor that varies the flow of current in a controlled manner by offering a wide range of resistance values. As the resistance of the variable resistor increases, the current through the circuit decreases and vice versa. It can also be used to control voltage between devices in a circuit.
Working of Variable Resistor
A variable resistor consists of a track that provides the resistance path. Two terminals of the device are connected to both ends of the track. The third terminal is connected to a wiper that determines the movement of the track. The motion of the wiper through the track helps in increasing and decreasing the resistance.
Tracks are usually constructed of a mixture of ceramics and metals, sometimes carbon. Carbon film-type variable resistors are often used because they require resistance materials.
Types of Variable Resistors
- Potentiometer
- Rheostat
- Presets
Symbols of Variable Resistors
Applications of Variable Resistors
- Oscillators
- Audio control/ Audio power amplifiers
- Home electrical appliances
- Transducers
- Motion and voltage control.