võimendirühmadest

Võimendirühmad, also known as amplifier classes, refer to the categorization of electronic amplifier circuits based on their operational characteristics and efficiency. These classes are primarily defined by the portion of the input signal waveform that the amplifier reproduces in its output. The most common classes are A, B, AB, and C.

Class A amplifiers are characterized by amplifying the entire input signal cycle. This means the active device within the amplifier is always conducting, resulting in high linearity and low distortion but also very low efficiency, as significant power is dissipated as heat even when no signal is present.

Class B amplifiers conduct for only half of the input signal cycle. This improves efficiency compared to Class A, but it can lead to crossover distortion when the signal transitions between the positive and negative halves of the cycle, as the active devices switch on and off.

Class AB amplifiers are a compromise between Class A and Class B. They conduct for more than half, but less than the full, input signal cycle. This design significantly reduces crossover distortion while maintaining better efficiency than Class A. It is a widely used class for audio amplifiers due to its good balance of performance and efficiency.

Class C amplifiers conduct for less than half of the input signal cycle. This results in very high efficiency but also introduces significant distortion. Therefore, Class C amplifiers are typically used in radio frequency applications where the output signal is often filtered or demodulated, making the distortion less critical. Other classes, such as Class D, which uses pulse-width modulation to achieve very high efficiency, also exist. The choice of amplifier class depends heavily on the specific application's requirements for power efficiency, linearity, and distortion.