Návrh analogových nízkofrekvenčních zesilovačů

Abstract

The first section of the dissertation gives an overview of principles of audio amplifiers, such as basic parameters (voltage gain, current gain, power gain, input impedance, output impedance, and dynamic range), basic integration (SE, SC, and SB), amplifier classes (A, B, AB and D), division of amplifiers into voltage and power amplifiers, types of couplings (direct, capacitive, and inductive), types of loads (resistive and inductive), and methods of operating point control (dynamics compressor and output amplifiers with self-alignment of an operating point depending upon excitation). In the second part, an amplifier with a dynamics compressor was designed; its functionality was verified with aid of RC construction, breadboard and Multisim 9 programme, and its features were measured. The dependence of output voltage on input voltage was measured and the measurement was used to calculate the dynamic range. The last section proposes an amplifier operating in the A class; same parameters as for dynamics compressor were measured and calculated. Then, measured parameters of both amplifiers were compared.