Most electrical devices and appliances have to be controlled. This can be signal, current, or voltage. One of the devices that are used for executing such controls is the potentiometer.
If you are a manufacturer and are planning to buy a potentiometer, this is your perfect place. We are going to discuss everything you should know about a potentiometer.
What is a potentiometer?
A potentiometer is a three-terminal resistor that is used for voltage divider applications. The potentiometer has a wiper that moves across the resistive element to vary the output voltage of the potentiometer. It can be linear or rotary potentiometers. It is basically a measuring instrument that is used to measure resistance.
The potentiometer has a cylindrical shaft that is made of plastic or metal. The rotational end of the potentiometer is called the wiper and it rotates in between two ends known as potentiometer and ground pin.
Potentiometers also come in different shapes and types, they come in horizontal or vertical types depending on their application. Vertical potentiometers use only two terminals while the third one serves for grounding purposes and horizontal potentiometers use all three terminals.
How does the potentiometer work?
The potentiometer works like a variable resistor which changes the level of voltage that is transmitted to the output signal. The potentiometer can be rotated or placed in such a way that it varies the resistance values according to the position of its shaft.
The potentiometer operates through three different resistive elements which are placed inside it. When you rotate the potentiometer. This changes the relative distance between two conductors and these conductors effectively change their mutual electrical influence on each other.
This varies the resistance values and we receive an analog voltage signal.
Potentiometers are mainly used to adjust the volume of an audio device or any other controlling applications where voltage level is required to be set.
Types of potentiometers
Potentiometers are classified into three main classes based on their working mechanism. These types are:
-Rotary potentiometer
-Linear potentiometer
-Digital potentiometers
Let’s look at each type so that you will be able to know the right one to buy.
Type 1: Rotary potentiometer
This potentiometer is known as the potentiometer that uses a shaft for adjusting its resistance. It has three pins and all of them are connected together at one end. The wiper moves across the resistive strip, this changes the output voltage level.
When rotating it, it can be turned 360 degrees or any number of turns required to change the values. One potentiometer can make around 10 turns and maintain accuracy and precision throughout.
Their main purpose is to adjust volume, there are also potentiometers available in the market which comes with an attached rotary switch for control purposes.
The potentiometer works on four different principles:
Linear Resistance Theory
As far as this potentiometer is concerned, the potentiometer works on a linear resistance theory. The potentiometer does not have any effect on the output voltage but just provides a change in its level.
Voltage Division Theory
With these potentiometers, the wiper is placed in such a way that it reduces the voltage to half when moving from left to right and vice versa. This also means that when comparing two different potentiometers, both will provide different results.
Displacement Current Theory
In this type, the displacement current created by the potentiometer allows an external magnetic field or induction field to influence the current flow between input terminals.
Dynamic Current Theory
In this case, potentiometers have a potentiometer wiper which allows the output to be proportional to displacement current. In this case, there is a lower output impedance and more voltage offset when potentiometers are in operation.
Type 2: Linear potentiometer
This potentiometer has a variable resistance strip that follows a linear trend. It changes in a straight line across its length with respect to input signal level. But they only have two terminals while the third terminal is used for grounding purposes.
In most cases, potentiometers come in multi-turn type with at least 10 turns. They also come in the form of a single turn potentiometer for low power applications such as volume control potentiometers, where higher values of resistance change may not be required.
Type 3: Digital potentiometers
Digital potentiometers are very similar in terms of their construction and functionally to linear potentiometer examples.
The only difference is that a potentiometer uses a resistor element that dissipates the power in the form of heat whereas a digital potentiometer works on electronic switches.
They have three terminals, one for power supply, second for the output signal, and third for ground. It allows users to change its resistance values via software control. Some might also be adjustable manually or by an external device such as a microcontroller etc.
Potentiometers are devices used when it comes to controlling equipment when there is a need to adjust settings when voltage needs to be altered. There are potentiometers that are adjustable manually, electronically, or by other means.
They normally come in three different types namely Linear potentiometers, Digital potentiometers, and Rotary potentiometers.
Linear potentiometers have a variable resistance strip that follows the linear trend.
It changes in a straight line across its length with respect to input signal level. But they only have two terminals while the third terminal is used for grounding purposes.
In most cases, potentiometers come in multi-turn type with at least 10 turns. They also come in the form of a single turn potentiometer for low power applications such as volume control potentiometers, where higher values of resistance change may not be required.
Digital potentiometers are very similar in terms of their construction and functionally to linear potentiometer examples.
The only difference is that potentiometers use a resistor element that dissipates the power in the form of heat whereas digital potentiometer works on electronic switches.
They have three terminals, one for power supply, second for the output signal, and third for ground. It allows users to change its resistance values via software control. Some might also be adjustable manually or by an external device such as a microcontroller etc.
Applications of potentiometer
Potentiometers are used in a wide range of applications, especially in modern electrical devices. These applications include:
Audio control
The potentiometers are mainly used for volume control which can be adjusted by turning potentiometers. Most potentiometers are connected to the potentiometer with a voltage divider circuit or rheostat, to make it adjustable by remote control wirelessly.
Measurement of the electrical potential difference
The potentiometer is connected between two different points in order to measure the electric potential difference between them. The potentiometer then returns this value back into the sender unit. This process can be done without changing any physical properties of the potentiometer.
Light dimming
This application also uses potentiometers for adjusting light intensity without changing its constant parameters. Potentiometers are connected in series with incandescent lamps so that they can be adjusted by potentiometers.
Scientific measurement
The potentiometers are used for measuring large forces for science experiments. In this case, potentiometers are connected with a spring to measure the forces applied to them.
Television
The potentiometers are used to control the brightness and contrast of the television picture. The potentiometers must be able to withstand large amounts of energy. Thus potentiometers should be designed in such a way that they can bear high voltage and currents.
Variable resistors
The potentiometer is known as a potentiometer when it is used for achieving variable resistance by manual adjustment. It is also called a potentiometer resistor because the potentiometer has both properties of Variable Resistance and Fixed Resistance.
Motion control
The potentiometers are used in motion control and drivers for certain types of electric motors. For example, the potentiometers can be built into a potentiometer that controls stepper motors. The potentiometer is then connected to an external circuit that allows users to control its speed by applying different voltages at its input.
Speed control
The potentiometer is connected with the ac induction motor for controlling its speed. It can also be used in variable frequency drives (VFD) which provide an on/off state to the low voltage ac supply without any switching noise.
Computer input device
Most computer keyboards contain potentiometers that control the key’s plastic parts such as `S’ or `A’ letters by pressing buttons on each side of the potentiometers. The plastic part of the letter then moves either up or down according to the pressure applied to it by the potentiometer.
How to choose the right potentiometer?
The potentiometer is classified into physical and electrical properties.
Physical properties:
The potentiometers can be classified on the basis of their three different measures such as length, height, and width. Length is the longest cross-sectional dimension while the width is the shortest.
Electrical properties
The potentiometers are also classified on the basis of electrical characteristics such as resistance value, maximum power rating, and current rating. A potentiometer with a higher current rating should be used in appliances where a large amount of energy flows through it.
The resistance value determines how much voltage will drop across the potentiometer when a load is attached to it. It has relatively low resistance when the potentiometer is turned fully clockwise whereas small resistance when the potentiometer is turned fully counter-clockwise. Maximum power rating is the maximum amount of power a potentiometer can handle.
It is related to the wattage of the potentiometer. The potentiometers with lower maximum power ratings should be used in appliances where a smaller amount of energy flows through them.
The potentiometers are also classified on the basis of the type of potentiometers such as trimmer potentiometers, preset potentiometers, and multi-turn potentiometers.
Trimmer potentiometer
A trimmer potentiometer has only one resistive element which provides variable quantity between two terminals. This type of potentiometer is used for applications that need precision control e.g., volume amplifier, etc.
Preset potentiometer
A preset potentiometer has resistance material deposited on a ceramic or plastic disc that acts as a sliding contact surface between metal wipers attached to it. The potentiometer does not work on the rotary principle, but the wiper moves across the potentiometer surface.
This type of potentiometer should be used in appliances that require fixed settings. For example, preset potentiometers are used for adjusting volume or sound control settings in radios and television sets.
Multi-turn potentiometer
A multi-turn potentiometer has a resistance element attached to a disc through a metal plate. It can rotate continuously between two terminals to achieve infinite resolution. The potentiometers are mostly used with computers which allow users to set the speed for controlling pointer movement on-screen display.
What is the cost of a potentiometer?
There are many different types of potentiometers that come in different sizes and specifications for each application. This implies that the potentiometers come at different prices.
Also, the price depends on where the potentiometer is being produced.
If potentiometers are being manufactured in the US, the price will be high. On the other hand, you can easily find affordable potentiometers in China.
Also, the body of the potentiometer coated with silver plating results in better conductivity which can increase the cost furthermore.
The potentiometers are mostly sold in the form of single units or kits for electrical appliances. The potentiometers can also be sold as set pre-wired with fixed resistor values.
You can also buy potentiometers wholesale. In this case, potentiometers are available at a bulk rate. This is what most manufacturers tend to do. A key advantage of this method is you will get good discount rates and reasonable prices.
Choosing Potentiometer Manufacturer and Supplier
So, do you think you are ready to buy potentiometers? Choosing the right brand matters. This is because potentiometer manufacturers are not all same. They have different qualities, sizes, and specifications to offer.
Choosing the best brand will guarantee you high-quality potentiometers. Quality potentiometers also ensure that potentiometer will work better and offer longer service life.
So, start your potentiometer search from the top potentiometer manufacturers only.
ICRFQ: Reliable Potentiometer Supplier in China
If you are planning to buy potentiometers in China, ICRFQ is the company to use. This potentiometers sourcing expert is committed to offering potentiometer and potentiometers parts and components that meet the quality standards.
ICRFQ: China Potentiometer Supplier also offers potentiometer kits, potentiometer wholesale, and potentiometers repair services at affordable prices.
So, visit ICRFQ.net if you need potentiometers.
If you want to find more Electronic Components Distributors, please check out the following articles:
Electronic Components Distributors In the USA
Electronic Components Distributors In UK
Electronic Components Distributors In China
Electronic Components Distributors In India
Electronic Components Distributors In Singapore
Electronic Components Distributors In Malaysia
Electronic Components Distributors In Vietnam
Electronic Components Distributors In South Korea
