jaoksVõimendiahelad

Amplifier circuits, known in Estonian as võimendiahelad, are electronic circuits designed to increase the amplitude of a signal. This increase in amplitude can refer to voltage, current, or power. Amplifiers are fundamental components in a vast array of electronic devices, from simple audio systems to complex telecommunications equipment and scientific instruments.

The basic principle of an amplifier circuit involves using a small input signal to control a larger output signal. This control is typically achieved by a semiconductor device such as a transistor or a vacuum tube, which acts as a variable resistor. The input signal modulates the conductivity of this device, thereby controlling the flow of a larger current from a power supply, which then generates the amplified output signal.

There are various types of amplifier circuits, categorized by their function, configuration, and operating class. Common configurations include common-emitter, common-collector, and common-base for bipolar junction transistors, and their field-effect transistor equivalents. Amplifier classes, such as Class A, Class B, Class AB, and Class C, describe how the active device is biased and how much of the input signal waveform is amplified, affecting efficiency and linearity.

The performance of an amplifier circuit is characterized by several key parameters, including gain (the ratio of output to input amplitude), bandwidth (the range of frequencies over which the amplifier operates effectively), input impedance (the impedance seen by the signal source), and output impedance (the impedance presented to the load). Distortion, noise, and power consumption are also critical considerations in amplifier design.