Võimendiklassid

Võimendiklassid, commonly referred to as amplifier classes, categorize electronic amplifiers based on their output stage design and signal handling characteristics. These classes primarily dictate the efficiency, linearity, and distortion levels of an amplifier.

Class A amplifiers are characterized by their continuous operation, with the output transistor always conducting current. This provides excellent linearity and minimal distortion, making them ideal for high-fidelity audio applications. However, Class A amplifiers are notoriously inefficient, generating significant heat and consuming a considerable amount of power.

Class B amplifiers operate by having the output transistors conduct only during half of the input signal cycle. This dual-transistor arrangement, often a push-pull configuration, significantly improves efficiency compared to Class A. The downside is crossover distortion, which occurs when the signal transitions between the two transistors.

Class AB amplifiers represent a compromise between Class A and Class B. They are designed so that the output transistors conduct for more than half, but not the entire, input signal cycle. This greatly reduces crossover distortion while maintaining a higher efficiency than Class A. Class AB is widely used in audio amplifiers due to its balanced performance.

Class C amplifiers are highly efficient but produce significant distortion. The output transistors conduct for less than half of the input cycle, making them unsuitable for linear amplification of audio signals. They are primarily used in radio frequency (RF) applications, such as transmitters, where efficiency is paramount and distortion can be managed through filtering.

Other classes, like Class D, employ pulse-width modulation (PWM) to achieve very high efficiencies, often exceeding 90%. These amplifiers rapidly switch output transistors between fully on and fully off states, generating a series of pulses whose width corresponds to the input signal. Class D amplifiers are increasingly popular in modern audio systems, especially where power consumption and heat generation are critical concerns.