Power-Amplifiers (1) (2).pptx for amplifiers

a presentation on power amplifiers for engineering students of electrical engineering

1. Power Amplifiers

2. Power Amplifiers Welcome to the world of power amplifiers! In this presentation, we will explore the definition, types, key specifications, applications, and future trends of power amplifiers.

3. its conduction angle is only 180° . the operating point (Q) is located at the cut-off point  •Due to common collector configuration, impedance matching is possible. difficult to get a pair of transistors ( npn and pnp ) that have similar characteristics. Has high efficiency upto  78.5%

4. T ypes of Power Amplifiers Class A Amplifiers High-quality output with low distortion, but less efficient due to continuous power consumption. Class B Amplifiers More efficient but can introduce crossover distortion using separate devices for positive and negative halves of the input waveform. Class AB Amplifiers Combines benefits of Class A and Class B, providing better efficiency and reduced distortion. Class C Amplifiers Highly efficient but suitable for applications requiring high power output with moderate distortion, like radio transmitters.

5. Basic Principles 1 Amplification Power amplifiers increase the amplitude of electrical signals . 2 Transistors They use transistors to amplify the input signal. 3 S upply Voltage They require a higher power supply voltage to operate efficiently.

6. PERFORMANCE PARAMETERS 1 EFFICIENCY It reveals us the percentage of DC power converted to AC power by  an amplifier . 2 The difference between the output & input of an amplifier  3 POWER DISSIPATION CAPABILITY DISTORTION t he ability to dissipate the heat by the power  transistor. Also known as power rating. 1 2 3

7. Types of Power Amplifiers . .

8. CLASS C AMPLIFIERS Class-C amplifier with LC circuit

9. Types of Power Amplifiers . . Class C Class AB Class B Class A

10. CLASS-A    Power AMPLIFIER Figure: Class-A power amplifier   and Transistor output characteristics   Figure: Transistor output characteristics  showing load line and Q-point ​ Has a conducting angle of 360degrees Low signal distortion levels Low efficiency Highest linearity The transistor in is always ON •The  common-emitter  (common-source)  amplifiers   fall into the class A category

11. TRANSFORMER COUPLED CLASS A AMPLIFIER   Efficiency: % nmax = 50%. :    Max power transfer is done.   High efficiency than direct coupled class A             amplifier Circuit is bulky and expensive. A transformer coupled class A amplifier  has a transformer in the collector load .  Fig.: Transformer coupled power amplifier

12.   Class-B Amplifier Transformer-Coupled  class-B Push–Pull amplifier Complementary  class-B Push-Pull Amplifier

13. CLASS AB AMPLIFIERS The output conducts between 180 and 360 of the ac input signal.  elimination of cross-over distortion.      Provides high efficiency and high-frequency response :    Cost is high.      APPLICATIONS:    Audio Frequency (AF) amplifiers in TVs. Etc.. CLASS AB AMPLIFIER CIRCUIT DIAGRAM

14. Common Applications Live Concerts Power amplifiers drive large sound systems to deliver high-quality audio in live music events. Home Theater Systems They provide immersive audio experiences for cinematic adventures in the comfort of your home. Musical Instruments Power amplifiers amplify electric signals from musical instruments for performances and recordings.

15. Conclusion 1 Recap of Key Points Power amplifiers amplify electrical signals, and different classes offer varying tradeoffs between efficiency and quality. 2 Future Developments As technology advances, power amplifiers will continue to evolve with a focus on energy efficiency and sustainability. 3 Q&A Session Use this opportunity to ask questions and dig deeper into the fascinating world of power amplifiers.