How To Control LED Brightness or DC Fan Speed with Arduino, Transistor, and Potentiometer

How To Control LED Brightness or DC Fan Speed with Arduino, Transistor, and Potentiometer

In this tutorial, I will show you how to control the brightness of an LED or the speed of a DC fan using an Arduino board, a BC547 transistor, and a potentiometer. Follow along for a step-by-step breakdown of the circuit, the code, and useful tips on optimizing your project. Components Required Arduino Board (e.g., Arduino Uno) BC547 Transistor (or BD139 for higher currents) Potentiometer (10kΩ recommended) LED or small DC fan (6V or 9V recommended) 9V battery or suitable power supply (7V - 12V) Connecting wires and breadboard Why Use a Transistor? The BC547 transistor acts as a switch and amplifier in this circuit. Since the Arduino cannot directly handle high-current loads like a DC fan, the transistor allows us to control higher currents with a low-power signal from the Arduino. If you need to control devices with higher currents, replace the BC547 with a BD139 transistor, which can handle more current. Power Supply Considerations Ensure that your power supply matches the requirements of your…