Everything you Need to know about Potentiometer

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Potentiometers are among the most common electronic components. They have been used in the electronics industry for many years and to achieve different purposes.  If you are planning to buy potentiometers to use on your device or application, then this is a perfect guide for you. We are going to discuss everything you should know about these vital components. You will also get sure tips for buying the best potentiometers from reputable and reliable sources.

What is a potentiometer?

To assist you with the definition, let’s split the term into two sections: “potential”, and “meter”. In this context, we have potential differences and metering. This means that a potentiometer has elements of metering the potential difference of a circuit.

Potentiometers are among the types of variable resistors that feature elements of mechanical adjustment systems that allow users to adjust the resistance value manually or mechanically.

We know that resistors are designed to regulate the flow of current in a circuit by offering significant levels of resistance. They can be fixed, which means that the resistance value is as defined by the manufacturer.

 Others are variable, meaning that users can adjust the value of resistance manually or automatically. This is where potentiometers come in. As a user, you can easily adjust the resistance manually and in doing so, you will be able to regulate the flow of current.

As variable resistors, potentiometers are designed to operate as voltage dividers. This means that they can be used for adjusting the output voltage of a circuit while at the same time determining the measuring or metering of the electrical potential of a circuit. This explains the name potentiometer.

When used as a voltage divider, a potentiometer will produce a continuous variable voltage which will be directly proportional to the position of the resistive element that is used for regulating the value of resistance.

In the world of electronics, potentiometers are always classified as passive electronic components.  They do not need a constant power supply to operate. Also, you don’t need to introduce an additional electric circuit or even extra elements to the primary circuit for the potentiometer to operate.

Evolution of potentiometers

Potentiometers are not new-age products, they came into existence shortly after the discovery of electric energy.  There is a rich history of potentiometers in the world of electronics.  Engineers and innovators thought it was necessary to develop a product or a system that would be used for regulating the flow of electric current in circuits and devices.

Many options and solutions were proposed and some of them were used. It wasn't until 1841 that the idea of using potentiometers came to life. In 1972, Thomas Edison invented the first working carbon potentiometer.

Like most electronic components, the first potentiometer was quite large and bulky. It was not very accurate due to some electrical physical constraints.  Modern potentiometers are smaller and easily portable. They are more accurate than they were before.

Technology has also made it possible to produce different packages for the potentiometers. This increases their levels of flexibility while at the same time expanding their scope of applications.

How do potentiometers work?

As we have stated, potentiometers are designed to control or regulate the flow of power in electric circuits.  They do this using a key electrical property: resistance.  By offering a specific level of resistance, a potentiometer will have the full ability and capacity to regulate the flow of electronics in a circuit.

Also, you should keep in mind that resistance is not constant. It varies depending on various factors such as the material, temperature, cross-sectional area, and length.

As long as all the other key parameters are kept constant, changing the length of a resistor will have a direct impact on the resistance value. This is the principle that defines the operation of a potentiometer.

The results or output of potentiometers are adjusted by controlling the rotary or linear position of a sliding contact along a resistance element. The adjustment can either lengthen or shorten the oath through which electricity flows in an electric circuit.

The main input voltage of the circuit is connected across the length of the resistive element. The output voltage is connected at the point between the fixed resistive element and the contact (which may be sliding or rotating).

By changing the position of the contact, you will be able to determine the amount of the input voltage that gets to the circuit. This will consequently have a direct impact on the output voltage that is coming from the circuit.

 It is quite hard to find an application where a potentiometer controls more than one watt. This is mainly because they tend to dissipate the input power when in operation. This will generate a significant amount of heat. This explains why they are mostly used in applications that involve controlling electric signals which are needed by other devices and components in electric circuits.

Types of potentiometers

 Potentiometers are classified into two broad categories: analog and digital. Analog potentiometers have been around for many years and have mechanical elements that allow users to adjust their resistance levels.

  Digital potentiometers are also used for controlling and regulating power only when they are used in digitally controlled circuits. Such circuits have two main operation modes; these are On and Off.

Also, there are two major types of analog potentiometers. These are rotary potentiometers and linear potentiometers. These two are named based on how a user controls them.

Rotary potentiometers have a rotating knob which can be adjusted in an angular direction to control the resistance level. It also has a shaft that is connected to the wiper element that is designed to slide across the resistive element. The position of the wiper on the element will give the exact resistance of the circuit. However, we also have shaftless potentiometers whereby control actions are executed by tools such as screwdrivers.

For the linear potentiometer, control actions are executed in a straight line. The linear motion will determine the final resistance value.

Other types of potentiometers

 Thanks to the technological advancement, many other types of potentiometers have been developed.  Most of the new models are curated to meet the needs of specific applications.  Here are other types of potentiometers that you should know:

· Trimmer/Preset: These are small potentiometers that are mounted on electronic devices. The device has a screwdriver that allows a user to make the required adjustments or calibrations. It is easy to make accurate calibration using a trimmer.

· Servo Pot: This type of potentiometer is usually found on electric motor applications. It is attached to the rotating shaft which has the capability of sensing locations by measuring pulses. It is quite a common potentiometer in the world of robotics.

· Logarithmic potentiometer: Also known as log pot, its construction features a resistance taper and a logarithmic form. It controls the resistance in an electric circuit logarithmically. It is mainly used in audio devices where it controls the volume of audio equipment.

· Slide potentiometer: It can have a single slide or dual slide. The operation entails sliding a contact on the resistance element. Dual slide potentiometers have a single slider that is designed to control two potentiometers positioned parallel to each other.  They are commonly used in filters and mixers.

· Motorized slide potentiometer: This is just like any other sliding potentiometer only that it has a timing belt driven by a timing pulley. This setup allows automation and also remote control. It is mainly used in industrial automated systems.

· Single and multi-run potentiometers: These potentiometers are named based on the number of rotations. For the single turn, it provides a single rotation of the control knob while the multi-turn offers multiple rotations on the control knob.

Resistance ratings of potentiometers

Since potentiometers are resistors, the most important parameter that you should check and confirm before buying one is its resistance ratings.

 As a variable resistor, the rating of the resistance rating is from one end of the terminal to another If a potentiometer is rated 1 kΩ, it means that the resistance across the elements is the same as that of a fixed resistance that has the same resistance ratings.

In addition to resistance rating, you should check out other important parameters such as the rated power, temperature coefficient, sliding noise, and even mechanical life. 

Conclusion

Potentiometers are variable resistors that have a wide range of applications in electronics.  In case you are building an electronic device or appliance and would like to add power control functionality to the system, you should consider using potentiometers.

As simple as they look, they play a vital role in regulating voltage and current in electric circuits with high levels of precision. This is usually true especially when you get the best potentiometer from reputable sources.

In case you are planning to buy potentiometers in bulk, you should consider choosing ICRFQ. We are a reputable international potentiometer distributor in China. We work with device manufacturers and suppliers around the world by helping them get suitable potentiometers for their applications. Talk to us and we will be glad to partner with you.