Výkonový zesilovač s měkkou limitací signálu

Abstract

This bachelor's thesis deals with the creation of a power amplifier module with sufficient power for demanding home listening, which will power a speaker system. The amplifier is made from commonly available parts, taking into account a sufficient power reserve, which affects the degree of reliability. In the design, emphasis is placed on the method of soft transition to limitation, that is, without sharp transitions that would negatively affect the radiated signal spectrum, with a high proportion of higher harmonics in the amplified output signal. The theoretical part describes the basic terms important in the field of power amplifiers, including basic properties. The following is a part devoted to practical implementation, which is supplemented by several methods of eliminating non-linear distortion. One method is to combine the output signal from two bridge-connected amplifiers with asymmetric limitation, and the second method of elimination is to connect an asymmetric limiter, which reduces the amplification before the limitation occurs. Finally, the results of both methods are evaluated in terms of the effect on the radiated frequency spectrum with the content of individual components of higher harmonic frequencies.