Lülitusvõimendusastmest

Lülitusvõimendusastmest, also known as a switching amplifier stage, is a type of electronic amplifier where the output transistor operates in a switching mode. Instead of amplifying the input signal linearly, the transistor is driven between its fully on (saturation) and fully off (cutoff) states. This on/off operation is controlled by the input signal, effectively modulating the power delivered to the load.

The primary advantage of a lülitus võimendusastmest is its high efficiency. Because the output transistor spends most of its time either fully on or fully off, the power dissipated as heat within the transistor is significantly reduced compared to a linear amplifier where the transistor operates in its active region for extended periods. This high efficiency leads to lower power consumption and less need for bulky heatsinks.

These amplifiers are commonly used in power supply applications, motor control, and audio amplifiers, particularly in Class D audio amplifiers. In Class D amplifiers, the input audio signal is typically pulse-width modulated (PWM) to control the switching of the output transistors. The resulting high-frequency switching signal is then filtered to reconstruct the amplified audio waveform. The switching frequency is much higher than the audio frequencies being amplified, allowing for efficient power delivery. The design of a lülitus võimendusastmest involves careful consideration of switching speed, filtering, and control circuitry to ensure accurate signal reproduction and minimize electromagnetic interference.