Introduction
The amplifier circuit is a very important one in the electronics field. The amplifiers are of different types and also in different sizes. You can build a very small to big amplifier as per your requirements.
So in this article, I would like to share the idea about how you can build a simple single transistor amplifier using a BC547 transistor. This single-transistor amplifier is quite easy to build. This amplifier circuit can be built without any doubts or problems because there are no complicated connections on it.
If you are a beginner in the audio amplifier section this circuit will help you to understand the working and improve your knowledge. The audio amplifier means “ Amplifying the input signal and providing output to the output speakers” To make this circuit you need to gather all of the required items with you. The required components are listed below.
Components Required
| No. | Component | Value | Quantity |
| 1 | NPN transistor | BC547 | 1 |
| 2 | Electriolytic capacitor | 47uf/25v | 1 |
| 3 | Speaker | 8 ohms | 1 |
| 4 | Resitor | 2K ohms | 1 |
| 5 | Battery | 9V DC | 1 |
Single Transistor Audio Amplifier Circuit Diagram
BC547 Transistor Pinout
Working
The entire audio amplifier setup is working based on the single NPN transistor of BC547. Direct audio signal is fed through a 47uf electrolytic capacitor.
The resistor R1 is the base resistor that helps to drive the transistor to the saturation point. The C1 will isolate the audio signal input section. The transistor is in the forwarding stage so the input signal will be amplified and provided to the output speakers. You can use 8 ohms 1-watt speakers on it.
