EDUCATIONAL AUDIO AMPLIFIER FOR THERMIONIC EFFECT DEMONSTRATION

Abstract

The vacuum tube devices use the thermionic effect for electronic equipment designs. It was the dominant technology from the beginning to the middle of the 20th century, but it is still used today in specific equipment such as audio amplifiers. The invention of vacuum tubes or electron tubes promote a great advance in electronic engineering, as they enabled communication technologies, such as the first radios, televisions and the development of the first electronic computer ENIAC (Electronic Numerical Integrator Analyzer and Computer) in 1946. In recent decades, this technology was being replaced by the use of silicon semiconductors, such as diodes, transistors, integrated circuits and microprocessors, used in current electronic projects. Even with the change in technology, many professional musicians, especially guitarists, prefer tube amplifiers, causing them to reach high commercial values. Experimental studies are always seen positively in academy, as they are complementary and stimulate scientific research. In this work, skills were developed, from the design of the electronic circuit to the use of 3D modeling software and the additive manufacturing application to build the amplifier chassis. The objectives of this work were to study the physical principles of operation of vacuum tubes and build a stereophonic sound amplifier with three watts of power per channel. After testing, we conclude that it worked as expected, resulting in an educational and commercial product.