Variable Resistor (Definition, Function and Types of Variable Resistor)

Variable Resistor: Definition, Function and Types

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What is variable resistor? Variable resistor is an electronic component. It is connected in an electronic circuit for modifying circuit resistance to control voltage or current of that circuit or part of that circuit. There are mainly two types of variable resistor track available one is linear track and other is logarithmic track. Before explaining types of variable resistor and variable resistor function, I will tell you how variable resistor works. Let’s see below.

The electrical resistance is varied by sliding a wiper contact along a resistance track. Sometimes the resistance is adjusted at preset value as required at the time of circuit building by adjusting screw attached to it and sometimes resistance can be adjusted as when required by controlling knob connected to it. The active resistance value of the variable resistor depends upon the position of the slider contact on the resistance track.

Variable Resistor: Definition, Function and Types

It mainly consists of a resistance track and a wiper contact. The wiper contact moves along the resistance track when customizable segment is balanced. There are mainly three different types of resistance track used in this resistor they are carbon track, cermet (ceramic and metal mixture) track and wire wound track.

Carbon track and cermet track are utilized for high resistance application though wire wound track is utilized for low resistance variable resistor. The resistance tracks for the most part are of round shape yet straight track is additionally utilized by and large. Here we will discuss mainly about types of variable resistor and variable resistor function.

Types of Variable Resistor

There are mainly two types of variable resistor track available one is linear track and other is logarithmic track. In linear track the resistance esteem differs directly with changing slider position on the track.

That means the resistance and the situation of slider, form a straight line characteristics curve. At the point when the resistance of variable resistor, fluctuates logarithmically with position of the slider contact on the resistance track, the track is alluded as logarithmic track.

The resistance value and type of track are set apart on the resistor itself. For example when a variable resistor is set apart as 5K9 LIN means it has maximum 5.9 kilo Ω resistance and has a direct opposition track.

Again when a resistor is set apart as 2M LOG, it will have maximum 2 mega Ω resistance and it has logarithmic track. Preset resistors are straight track type.

In any case, the variable resistors utilized for volume control in sound framework are primarily LOG type as our ears have logarithmic reaction to the commotion. In GOL resistor, the resistance changes gradually at starting and quickly at towards end of the track.

See Also: Resistances in Series and Parallel Combinations

Variable Resistor Function

A variable resistor can be used mainly in two different ways. When one end of resistance track and wiper terminal is connected with circuit then current through the resistor limits according to the position of the wiper contact on the resistance track.

As the wiper contact slides from the associated end of the resistance track, the resistive estimation of the resistor increments and current goes down through the circuit. That means the variable resistor carries on like a rheostat.

Another use is as potentiometer. For this situation the two closures of resistance track are associated with a voltage source. Hence voltage drop over the resistance track is equal to estimation of voltage source.

Now the output or load circuit is connected across one end of the resistance track and wiped terminal. Subsequently voltage over the heap terminals is the portion of source voltage and it relies on the situation of the wiper terminals on the the resistance track.

This is another widely used application of variable resistors. This is needless to say, potentiometers are used to control voltages whereas rheostats are used to control electric currents.

See Also: Types of Resistor Carbon, Composition, Film and Non Linear

Variable Resistor Conclusion

After going through the above portion of variable resistor we can now establish types of variable resistor and variable resistor function. I hope you enjoy when reading this article, thank you.