Engineering Commons^™

Re-Design Of Precision Signal Conditioning Circuit For Detecting Schumann Resonance, Rohith Bikkina

Graduate Theses, Dissertations, and Problem Reports

Extremely low frequencies signals are waves between 3 to 30Hz and corresponding wavelengths between 10,000 to 100,000 kilometers. The specific signals used here are generated from lightning and are excited at frequencies around 8Hz, 14Hz, 20Hz. These are often called Schumann Resonance frequencies. Several stations have been built around the world for identifying ELF waves. All of those required a sparsely populated area that was far away from electric power lines because of interference from electric noise at 50 Hz and 60Hz. This project develops and tests an amplifier and filter circuit that should assist in identifying the Schumann Resonance …

Dynamic Voltage Rail Audio Amplifier, Evan Von Duhn, Timothy Oshatiouk, Slavisa Tosanovic, Andrew Cantrell

Williams Honors College, Honors Research Projects

The goal of this project is to create a high-quality, power-efficient audio amplifier. Most modern audio amplifiers use a constant amount of power regardless of the signal that is being amplified. This means that both loud and quiet portions of the audio signal require the same amount of power to amplify. The idea for this high-quality, power-efficient audio amplifier is that the quieter portions of the audio signal can be amplified using less power. This will be achieved by first analyzing the audio signal and controlling the power source based on the signal’s needs. Therefore, louder parts of the audio …

Dual Method Headphone Amplifier, Joseph S. Gross, Timothy P. Murphy

Electrical Engineering

Many high impedance headphones underperform their full potential when directly connected to the audio source. Amplifiers boost the audio signal and provide the headphones with sufficient power to ensure their maximum performance. The invention of transistors caused vacuum tube implementation to decline, leaving many audiophiles unsatisfied with the transistor’s sound signature. Vacuum tubes and transistors both amplify signals, however the distinct “tube sound” has vanished.

We have designed and created a product where the user selectively switches between solid-state transistor and tube amplification to compare the sound signatures of each amplification method. The ability to switch between the solid-state and …

Audio Dsp Amplifier, William Saba, Nicholas Barany

Electrical Engineering

The key concept of this project is to create a microcontroller system that serves as an interface between a DSP board and a total of 4 amplifier channels. The fully integrated system will provide a fully inclusive audio DSP amplifier for use in 2.1 or bi-amplified stereo speaker setups. The project will focus on developing an intuitive interface that is operable from the device or a computer that programs the DSP board for various speaker applications. The finished design will provide a custom computer sound amplifier in one package, eliminating the need for multiple components by interfacing two stereo amplifiers, …

Dual Channel Matrix Switch Audio Receiver, Austin Fox

Electrical Engineering

The Dual Channel Matrix Switch Audio Receiver controls 2 separate audio output channels. Each channel plays any of the system's 3 inputs. This controller enables a user to play two separate audio signals through two separate speaker channels. The system design allows audio input from 2 RCA sources or 1 RCA source and a phono source. The system outputs an audio signal for each output simultaneously at up to 36W on each channel for an 8Ω load. The device allows a user to control the audio input and the volume of each output channel. An Arduino Uno R3 microcontroller interfaced …

Digital Guitar Effects Unit And Amplifier, Kevin Salvador

Electrical Engineering

This report outlines the design and implementation of a digital guitar effects unit and amplifier. The main portion of this project consisted of the digital equalizer and effects. Several commercial equalizers were researched in order to decide the typical frequency bands and average amount of bands total. Eventually 8 bands were selected. A range of approximately 20Hz-3kHz was chosen based on test data of guitar signals. Popular effects that were incorporated in this project include Distortion, Echo, Reverb, Chorus and Flanger. The digital processor chosen was a Texas Instruments c6713 floating point processor. Designs for the various filters were done …