The device with a three-terminal configuration is called a variable resistor. Rheostat and potentiometer both come under the category of variable resistors. The function of the variable resistor is to provide the variable amount of resistance within an electrical circuit.
Rheostat vs Potentiometer
The difference between rheostat and Potentiometer is that Rheostat is a special resistor that consists of two terminals and it creates a relation between the wiper and one side. A potentiometer is a device consisting of three terminals with an adjusting knob for regulating the resistance. The work of a rheostat is to change the resistance according to use. While the work of a potentiometer is that it is used as a measuring device.
A rheostat is a device that is used basically to regulate the resistance i.e., either to reduce or increase the flow of current manually. It is a very common kind of variable resistor. It can be said as the power controlling instruments and are used in various appliances like oven, heaters for managing the intensity of light and monitor the speed.
A potentiometer is used as a measuring device. It is used to measure the voltage of an electrical device. It can also be used to control the volumes of electrical devices like audio speakers.
Comparison Table
| Parameters of Comparison | Rheostat | Potentiometer |
|---|---|---|
| Made of | Various materials like and carbon disks, fluids and metal ribbon. | Resistive elements like cermet, graphite, wire, and carbon particles. |
| Use | Vary resistance | Measuring instrument |
| Function | Control the flow | Voltage dividing |
| Connection | Serial | Parallel |
| Flexibility | Cannot be used as Potentiometer. | Can be used as a rheostat. |
| Voltage Dividing | Cannot divide | Can divide |
What is Rheostat?
A rheostat is used to vary the flow of current in an electrical circuit. It is controlled manually by increasing or decreasing the resistance. It can change the resistance without any disturbance or interruption.
There are majorly three types of Rheostat. Preset, Rotary and Linear. Preset Rheostat is used in printed circuit boards usually. Rotary is used when the slider or resistive element of the rheostat moves in a circular direction.
A linear rheostat is used when the slider and resistive element moves in a linear or straight direction. There are various applications of rheostat like it is used in the devices where high voltage is required, it is also used to dim lights as it can change the intensity of lights and it is used to control the volume of a device like radio or speed of a motor.
What is Potentiometer?
There are various terms through which different types of the potentiometer is used to describe in electronic industry. It includes a trim pot, slide pot and thumb pot.
Two types of potentiometers can be adjusted manually. They are Linear and Rotary Potentiometer. Linear is when the wiper moves in a straight direction.
It cannot divide voltage. It is connected with parallel in an electrical circuit. It is used to control the volume in audio systems and acts as a transducer in controlling television.
Main Differences Between Rheostat and Potentiometer
- A rheostat cannot be used as Potentiometer. A potentiometer can be used as a rheostat.
- A rheostat cannot divide voltage. A potentiometer can divide voltage.
References
- https://aip.scitation.org/doi/abs/10.1063/1.1751472
- https://aapt.scitation.org/doi/abs/10.1119/1.1934883
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