Identify variable resistors in a circuit board (2024)

Identifying variable resistors on a circuit board can be crucial for troubleshooting, modifying, or understanding the circuit’s functionality.

A variable resistor differs from a fixed resistor by its adjustable knob, slider, or wiper, allowing for resistance adjustment. It often has a distinct, sometimes larger appearance on the board. To identify variable resistors, visually inspect the circuit and can also connect a multimeter in resistance mode across the component; if the resistance changes when the knob is adjusted, it’s a variable resistor.

In this article, let’s do a fun activity to identify variable resistors in a circuit board.

Identify variable resistors

A Variable resistor is an essential electronic component that allows the adjustment of resistance value. To understand the circuit functionality the identification of components is necessary.

Let’s discuss how you can identify variable resistors in a circuit board.

1. Visual inspection

By visual inspection, you can identify the variable resistor. Look for components that resemble resistors.

Variable resistors typically have a cylindrical or rectangular shape with three terminals or pins. They may be larger than regular resistors and often stand out due to their unique appearance.

2. Component labeling

You can also identify the variable resistor by examining the circuit board. Examine the circuit board for any markings or labels that indicate the presence of a variable resistor.

These labels can include designations such as “VR,” “POT,” or a specific value range like “1K” or “10K.”

Such labeling helps identify the component’s purpose and can guide you in locating the variable resistor. With these labels variable resistors are identified.

3. Mechanical adjustment

The typical feature of variable resistors is a rotating or sliding control mechanism that allows you to change the resistance value by physically turning or sliding a knob or lever.

This mechanical adjustment of the variable resistors distinguished these types of resistors from other normal resistors.

Look for components with protruding knobs, sliders, or wipers that suggest the presence of a variable resistor. If the component has one of these then it is a variable resistor.

4. Terminal configuration

Usually, variable resistors have three terminals. The movable or wiper terminal is the third terminal; the other two are the fixed ends.

A movable contact that may be changed to alter the resistance value is connected to the wiper terminal. To find possible variable resistors, look for components that have three terminals.

5. Datasheet or schematic diagram

You can also find the variable resistor by studying and understanding a circuit’s datasheet or schematic diagram.

Consult the datasheet or schematic diagram for the circuit board, if it is available. These publications offer insightful details regarding the various parts of the circuit, such as the variable resistors.

Seek out particular labels, numbers, or symbols that denote the existence of a variable resistor. Accurately recognizing variable resistors can be greatly aided by datasheets and schematics.

Fun activity: Find the variable resistor

Till now you know how can you find a variable resistor in a circuit. You have to understand a variable resistor is a three-terminal component and it has a larger size than a fixed resistor.

Let’s consider a circuit board to identify variable resistors.

Start with observing the circuit, by observing it you will understand different components and their physical appearance. As the variable resistor is a three-terminal device with a slider, knob, or wiper to adjust its resistance value.

So when you see a component with a physical appearance like this, it must be a variable resistor. In the above picture, the blue color components have a knob and have three terminals so it means it is a variable resistor.

Now in this next circuit identify the variable resistor and let us know in the comment section.

This little fun activity will help you to find the variable resistor in any circuit.

Conclusion

In the applications where you need varying resistance then a variable resistor plays a very important role. It has the quality to change the resistance.

It has three terminals, two fixed terminals and the third one is movable. The movable contact can be a knob, slider, or wiper and is responsible for changing the resistance value.

To determine, modify, or understand the operation of a circuit, it can be essential to identify the variable resistors on the circuit board.

You can successfully identify variable resistors by visually inspecting the board, reading component labeling, observing mechanical adjustment mechanisms, examining terminal configurations, and referring to datasheets or schematics.

Since variable resistors come in various sizes and shapes, it’s important to combine these identification techniques to get precise results.

This was all about the identification of variable resistors, I hope you would like it.

Thank you and stay blessed…