2N3055 Power Amplifier Circuit Diagram

Introduction

The 2N3055 power amplifier circuit is a classic design that has been used in audio sections for decades. This circuit was introduced in the 1960s by RCA and has since become one of the most famous and widely used power amplifier circuits. The circuit is based on the 2N3055 power transistor, which is capable of delivering high power and having excellent thermal characteristics.

The 2N3055 power amplifier circuit is known for its simplicity and reliability, making it an ideal choice for beginners and professionals alike. The circuit can be easily built with only a few components, making it an affordable choice for hobbyists and enthusiasts.

Another benefit of this amplifier is its versatility. The circuit can be used in a wide range of applications, from home theaters and PA systems to tube amps and guitar amplifiers. The circuit’s flexibility and ease of use have contributed to its enduring popularity among audio enthusiasts.

In this article, we will discuss the basic working principle of the 2N3055 amplifier circuit and its applications. Additionally, we will introduce a modification to the circuit that uses the BD139 transistor for enhanced performance.

Circuit Diagram

of 2N3055 Power Amplifier Circuit

2N3055 Power Amplifier Circuit Diagram modified — **2N3055 Power Amplifier Circuit Diagram**

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Working Explanation

of 2N3055 Power Amplifier Circuit

The 2N3055 power amplifier circuit is a simple class AB amplifier that uses a single transistor to deliver high power. The basic operation of the circuit involves the use of a voltage divider network to bias the transistor at a specific quiescent point. The input signal is then amplified by the transistor, which drives the output speaker.

The 2N3055 transistor is capable of delivering high power and having high thermal stability, making it an ideal choice for power amplifier applications. The transistor’s thermal characteristics are essential in preventing thermal runaway, which can cause damage to the transistor and other components in the circuit.

The BD139 Transistor Modification:

While the 2N3055 amplifier circuit is a reliable and proven design, it can benefit from some modifications to improve its performance. One such modification is the use of the BD139 transistor.

The BD139 is a complementary transistor to the 2N3055 and is commonly used in voltage regulators and power supply circuits. The BD139 has a higher current gain than the 2N3055, making it an ideal choice for use in the input stage of the amplifier circuit.

The modification involves replacing the input transistor with the BD139 and adjusting the biasing network to accommodate the new transistor. This modification results in a more efficient and stable amplifier circuit that delivers improved performance and fidelity.

Components List

of 2N3055 Power Amplifier Circuit

2N3055 Transistor x 1
BD139 Transistor x 1
10uf Capacitor x 1
82 Ohm Resister x 1
47k Resister x 1
100k Resister x 1
50k Potentiometer x 1
12V Power Supply
4 ohm Speaker

Conclusion

The 2N3055 power amplifier circuit is a classic design that has been used in audio sections for decades. The circuit’s simplicity, reliability, and versatility have contributed to its enduring popularity among audio enthusiasts.

The modification using the BD139 transistor enhances the amplifier circuit’s performance, resulting in improved efficiency and stability. The modification is easy to implement and can be done with only a few components.

Overall, the amplifier is an excellent choice for anyone looking to build a simple and reliable amplifier circuit. With the addition of the BD139 transistor modification, the circuit can be enhanced to deliver superior performance and fidelity.