This is an interesting practical project which even a novice can build! It is a simple single transistor audio amplifier which can be powered by 1.5V to 5V. This project uses few components which you can easily get even from a dead circuit.
The circuit is a simple audio amplifier using a single NPN bipolar junction transistor (BJT). The circuit can drive a 0.2W to 5W Speaker of 3 – 4Ω impedance. The input voltages range from 1.5V from a single cell to 5V DC single supply.
Below are the components you will need for this simple project. You can find these components even in a dead electronic panel or circuit board.
- C2655 (1)
- 22KΩ (1)
- 10uF (1)
- 1.5V to 5V Cell (2)
- 3Ω impedance, 0.2W to 15W Speaker
If you have successfully constructed the circuit, you’d probably notice some distortions in the sound quality. But don’t worry, there is still simple modification you can do to improve the quality. A resistor with a low resistance like 3Ω to 12Ω can be connected in series from the emitter (E) of the transistor to the ground (0V) supply to improve the output sound quality.