Diseño y construcción de un amplicador de audio de alta eficiencia energética.

The objective of this project is the design and construction of a Class D power amplifier for audio signal amplification, based on the knowledge obtained in the Telecommunication Systems degree, specially in the topics of electronics and signal theory. The project is structured in three differentiated parts. In the first place, the theoretical bases necessary for the elaboration of the design are presented: description of the audio signal, preamplifiers, review of the different classes of linear power amplifiers, detailed analysis of the Class D switched power amplifier and review of different digital processing techniques, specifically equalization and digital predistortion. Next, a design of a Class D switched power amplifier made with commercial components is proposed. The design is composed of a microcontroller, a DAC, a PWM modulator, a NOT gate, a power stage and a low-pass demodulation filter. The working principle of each component is analyzed and all the necessary calculations are made. Simulations are performed at the block and circuit level. Finally, the necessary components are acquired and a real prototype is built on protoboards following the previous design. The correct operation of each block and of the total system is checked through oscilloscope measurements. The system is equalized and the performance of the prototype is measured. The project has a practical approach and supposes a personal introduction to audio electronics