Variable resistor function in a circuit (2024)
There are various types of resistors but the two main types are fixed and variable resistors. Variable resistor function depends upon the project you are working on.
A variable resistor controls the resistance in a circuit, allowing for adjustment of current and voltage. By moving a wiper along a resistive path, the resistance can increase or decrease, influencing the operation of connected components, such as dimming lights or adjusting motor speed. This makes variable resistors versatile for tasks requiring dynamic control over electrical properties.
In this article, we’ll discuss the variable resistor function in a circuit.
Variable resistor functions
A variable resistor is a type of resistor that gives us the freedom to adjust the resistor. It is a three-terminal device used to control the current and voltage in the circuit.
For lots of functions of variable resistor is used. Let’s discuss the variable resistor function in detail.
1. Voltage control
A variable resistor can be used to control the voltage in the circuit. When changing the resistance value, the voltage drop across the variable resistor is also altered.
This will in turn affect the voltage at the output or across other components in the circuit.
For understanding let’s consider a simple circuit containing a voltage source such as a battery, a variable resistor, and a load component such as a light bulb.
When the variable resistor is at its maximum, all source voltage will drop across the resistor and the load will have the lowest voltage.
Conversely, when the resistance of the variable resistor is at its minimum value (or close to it), the majority of the voltage from the source is dropped across the load component.
As a result, the voltage across the load component is higher, and it receives a higher voltage. By adjusting the resistance value we can control the distribution of voltage in the circuit.
2. Current control
As a variable resistor controls the voltage in the circuit, it also controls the current in the circuit. By altering the value of resistance of the variable resistor the current flow in the circuit also changes.
When the resistance is maximum the current flow will be minimum and when the resistance is minimum current flow will be maximum. So by adjusting the variable resistor resistance, the current can be controlled or limited.
3. Tunning and calibration
Variable resistors are often used to fine-tune and calibrate circuits during setup. A circuit can be brought into its ideal functioning range by varying the resistance.
Without requiring a major redesign, this fine-tuning guarantees the item operates as intended.
Sensor calibration, analog-to-digital converter (ADC) configurations and other applications requiring exact control use variable resistors.
4. Attenuation of signal
Variable resistors are utilized in signal processing. For attenuation or reduction of signals variable resistors are used.
By increasing the resistance, the resistor can limit the amount of signal passing through, effectively reducing its strength or volume.
Volume control or in circuits where signal levels need to be kept within certain limits such as audio devices variable resistors are used.
5. Brightness and speed control
Variable resistors control brightness in lighting circuits and speed in motor circuits.
By increasing or decreasing the resistance value they control the current reaching a load, like a light or a motor, which directly affects brightness or speed.
Dimmer switches for lights and variable-speed controls for fans or DC motors are common examples.
Conclusion
A variable resistor is a type of resistor in which we can change its resistance. The resistive element, movable contact (wiper), and two fixed terminals are the main components of a variable resistor.
The movable contact helps to change the resistance value. The wiper is moved over the resistive element which alters the resistance value.
There are different types of variable resistors such as potentiometers, rheostats, photoresistors, and thermistors.
The potentiometer and rheostat are used to control voltage and current. A photoresistor is a light-dependent resistor a common type of variable resistor and a thermistor is a temperature-dependent variable resistor.
The variable resistor function is to control voltage and current in the circuit. By changing the resistance value current or voltage value will change.
This was all about the variable resistor function in the circuit, I hope it will be helpful.
Thank you and have a blessed life…
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