Potentiometers or variable resistors have been a part of our life for a long time. The Fan Speed Regulator, the music volume control of a boom box, or temperature control on an oven. Today the potentiometer are being replaced by software controls. For example consider your music volume control, it no longer a potentiometer that you need to turn around.
Our Potentiometer circuit will be including only a 9V battery and it is completely safe. It is recommended that you also refer to Basic Safety and Introduction for Young Engineers for more detailed understanding of Safety Requirements.
In this activity you will control electronic devices with the help of the potentiometer.
- 1 x 100 Ohm Resistor
- 2 x LED
- 1 x Buzzer
- 1 x DC Motor or Geared Motor (Optional)
You can find these components at your nearest radio shack or an online store.
A potentiometer is an electronic component that has a variable resistance. It consists of a resistive track and a wiper. The wiper slides along the track and the resistance varies accordingly. The potentiometer has 3 terminals: 2 terminals for the track on each of its side and 1 terminal to the wiper. The wiper moves when the know on the potentiometer is turned and we can control the output of a circuit.
How does a Potentiometer work
A potentiometer works by varying the resistance of a circuit. When the wiper is at one end of the track, the resistance between one of the terminals and the wiper is low, and the resistance between the other terminal and the wiper is high. When the wiper is at the other end of the track, the situation is reversed, and the resistance between the first terminal and the wiper is high, while the resistance between the second terminal and the wiper is low. When the wiper is in the middle of the track, the resistance between the two terminals is equal.
Circuit Diagram – LED Dimmer
The potentiometer in our activity here will control the brightness of the LED. By adjusting the resistance of the potentiometer we can control the amount of current flowing in the circuit which will then in return make the LED dimmer or brighter. You can turn the pot in both the direction and check the brightness (Please do not do this step without connection the 100 Ohms resistor. If done, the LED will burn out.)
Circuit Diagram – Buzzer Volume Control
The potentiometer in our activity here will control the volume of the Buzzer. By adjusting the resistance of the potentiometer we can control the amount of current flowing in the circuit which will then in return make the Buzzer get louder or softer. You can turn the pot in both the direction and check the volume.
Potentiometers are versatile electronic components that can be used in a variety of projects. We can control various appliances with a potentiometer. Potentiometer has a range of resistance and is hence analog in nature. We can develop a lot of projects with the help of analog properties of various sensors.