A high power amplifier is a non-linear device that amplifies a small signal to a significant level, all the while maintaining the smaller signal’s parameters. Amplifiers are an essential part of modern-day electronics. Amplifiers typically come in formats such as power amplifiers, preamplifiers & integrated amplifiers. So, in this project, we are going to build a high-power amplifier (100Watts) using TIP122 TIP127 Darlington pair transistors.
TIP122 & TIP127 are Darlington pair NPN & PNP transistor pair. they function like normal NPN/PNP transistors, but since they have a Darlington pair inside they have a good collector current rating of about 5A and a gain of about 1000. They can withstand about 100V across their Collector-Emitter terminal hence they can be used to drive heavy loads.
Hardware Components
The following components are required to make High Power Amplifier Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | NPN Transistor | TIP222 | 1 |
| 2. | Condensor Mic | – | 1 |
| 3. | PNP Transistor | TIP127 | 1 |
| 4. | Audio Jack port (Female) | 3.5mm | 1 |
| 5. | Loudspeakers | – | 1 |
| 6. | Potentiometer | 1K | 1 |
| 7. | Audio Jack (male) | 3.5mm | 1 |
| 8. | Capacitor | 470uF | 1 |
| 9. | DC Supply | 12V | 1 |
| 10. | Breadboard | – | 1 |
| 11. | Connecting Wires | – | 1 |
| 12. | Resistor | 150k | 1 |
TIP122 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of TIP122
TIP127 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of TIP127
High Power Amplifier Circuit
Working Explanation
The working of this high-power amplifier is similar to any simple amplifier circuit. what makes this circuit unique is the robust & high-power TIP122/127 Darlington transistor pair. An Audio input taken from a general audio transducer such as a mic acts as the DC control signal for the transistor Q1. Here, a capacitor (47uF) blocks the DC component, allowing only the AC component of the signal to pass through. Transistor Q1 amplifies the signal & sends it to the base of the transistor Q2.
The TIP127 further amplifies the input signal & directs it to an audio output device such as a loudspeaker. This circuit can be operated easily by using a 12V DC Power Supply.
Applications
- Generally functions as an integral part of high power speakers & music equipment.
- They have also found their way into militaristic applications such as acoustic weaponry.
- Widely used in sound systems such as speakers, high-power megaphones & large-scale acoustic systems.
