"Large Signal (Power) Amplifiers" is a topic focused on electronic circuits designed to deliver substantial power to a load, contrasting with small-signal amplifiers that primarily deal with voltage or current amplification.
The core of this topic revolves around amplifier classes (Class A, B, AB, C), which are distinguished by the portion of the input signal cycle during which the active device (transistor) conducts. Each class has unique characteristics regarding efficiency, linearity, and distortion. For instance, Class A offers high linearity but low efficiency, while Class C provides high efficiency but poor linearity. Class B and AB are often used in push-pull configurations to achieve better efficiency than Class A while maintaining reasonable linearity (with Class AB specifically addressing crossover distortion found in Class B).
Key performance metrics like power conversion efficiency (the ratio of AC output power to DC input power) and power dissipation are crucial. Understanding thermal management, including the use of heat sinks, is vital because power transistors generate significant heat. The topic also covers typical output stage designs that facilitate the delivery of high power to various loads, such as loudspeakers.
