a potentiometer often known as a part or a part meter is a free terminal mechanically driven rotating analog device that can be found and utilized in a wide range of electronic projects while watching this video you will learn the working principles of a potentiometer and how it is used in the most common electrical circuits okay let's get started a potentiometer is a manually adjustable variable resistor and it is so useful when it compares to a fixed resistor why you may ask imagine we have a 100 ohm fixed resistor if for any reason we decide to change the resistance for example to 200 ohms we have to change the resistor itself we need to get a new value resistor and that's where a potentiometer comes in useful here you can easily change the resistance value just by turning the knob on top of the potentiometer let's have a look at the different parts of a potentiometer first it is better to remove the potentiometer cover to see the inner structure as well a potentiometer has three terminals or connection points among two are fixed and one is variable the two fixed outer terminals are connected to both ends of the resistive element form into an arc of a circle responsible for establishing an electrical resistance you should note that the maximum resistance of a potentiometer is placed inside this semicircular pattern the variable middle terminal is connected to a sliding contact often referred to as a wiper attached with a rotary knob it means whenever we turn the knob the wiper will run across the resistive element results in making good electrical contact now let's find out how a potentiometer works to do this we use one of the most beloved industrial tools the multimeter imagine our potentiometer has a resistance of 10 kilo ohms so if we hook up the two outer terminals to the multimeter it shows the maximum resistance of the potentiometer that is 10 kilo ohms now i connect one side of the multimeter to the middle terminal and the other side to one of the outer terminals of the potentiometer this way the resistance value that the multimeter shows depends on the position of the wiper over the resistive element if we adjust the wiper in such a way that increases the resistive path between the measured outer terminal and the wiper the resistance increases and if we set the wiper in such a way that decreases the resistive path the resistance decreases note that if we connect another multimeters probes to the middle terminal and the other unused outer terminal of the potentiometer the sum of the resistance shown by these two multimeters is equal to the maximum resistance of the potentiometer to fulfill your learning you need to know how the potentiometer can be connected in different configurations in the most common electronic applications if only the middle terminal or wiper and one of the outer terminals of the potentiometer are used it will act as a variable resistor in this application example we use a potentiometer for brightness control here we connect the wiper to the positive terminal of the power supply and one end of the resistive element to the positive side of the led as you may know the amount of current flowing through the led determines its brightness if we turn the potentiometer in a way that increases the resistance the current flow decreases thus the led will become dimmer and if we adjust a potentiometer in a way that decreases the resistance the current flow increases thus the led will become brighter now let's switch to another application example where all three terminals of the potentiometer are being used in wiring configuration this way we can say the potentiometer will act as a voltage divider in this diagram we use a potentiometer for motor speed control here we apply a reference voltage across the whole length of the resistive element and connect the wiper to the dc motor this way by turning the knob and controlling the position of the wiper we can allow enough voltage to pass through the potentiometer if we adjust the wiper in a way that introduces a high resistance more voltage will derive to the motor resulting in turning the dc motor faster and if we set the wiper in such a way that introduces the low resistance less voltage will apply to the motor causing the dc motor to turn slower that's all we have for you today we hope you got familiar with the basic concepts of a potentiometer if you have a unique experience using potentiometers in your projects please share it with us in the comment section also if you found this video helpful please encourage us by liking the video subscribing to our channel and pressing the bell icon so you can get notifications whenever we publish new out of the oven videos and keep motivating us to produce more informative videos [Music]