The two most common components used in electronics are potentiometer and rheostat. A potentiometer is not only used as an electronic component but also as a measuring instrument whereas rheostat is generally used to vary circuit resistance. These two elements are used for laboratory as well as for industrial applications.
Why do we use rheostat in a potentiometer?
The crucial difference between the potentiometer and the rheostat is the use of a potentiometer to calculate the estimated electromotive force (EMF) and thus regulate the voltage of the circuit as compared to the rheostat. A rheostat is an instrument that regulates current flow through a circuit by varying resistance.
We cannot use rheostat as a potentiometer, but on the other hand, a potentiometer can be used as a rheostat. A rheostat is used deliberately in a potentiometer to lower the current of the potentiometer and to keep it constantly in circulation to improve its sensitivity.
Difference between rheostat and potentiometer
Two terminal devices: The rheostat is a two-terminal device that only forms a connection to one end and a wiper or slider.
Main purpose: The main purpose of rheostat is to vary the amount of current.
Instrument type: it is considered as a variable resistor.
Composition: The rheostat is composed of different materials like a metallic ribbon or carbon disks.
Connection type: It forms a series connection with the circuit.
Suitability of use: It is suitable for high power application.
Application: In device testing purposes, rheostats are used in the laboratory. They are also used for controlling the motor speed. Apart from this, their main use is to control the intensity of the light by connecting it in series with the light. When increasing the resistance, the luminosity of the light decreases while the luminosity is increased if we decrease the resistance.
Three terminal devices: A potentiometer is an instrument of three terminals whose ends together with the wiper are attached to the circuit.
Main purpose: The potentiometer configuration is used to feed voltage in any circuit.
Instrument type: It is considered a type of sensor.
Composition: The composition of a potentiometer is the graphite material.
Connection type: It is mostly connected in parallel connection with the circuit.
Suitability of use: The potentiometer uses are mainly in low power application.
Application: They are mostly used in electronics circuits to vary input voltage and can be used as a displacement transducer. The common and well-known application of potentiometer is audio control as they are used in an audio device to control the loudness.