Engineering Commons^™

Mixing Digital And Analog Audio Signals, David Robison

Electrical Engineering

I have been playing the drums for thirteen years. I started out on an electric drum set and then progressed to an acoustic set. I have always wondered what it would sound like to combine the two types of sounds and this senior project dissected that interest to its raw form. Delving into the problems and solutions of combining digital and analog audio signals intrigued me and thus, became my senior project. The design process included research into the analog and digital realms, computer simulations, and actual implementation successes and failures.

The signal path begins at the bass drum where …

Aircraft Data Collection System, Amy Kronsteiner, Danny Marx, Collin Heller, Nathaniel Garcia, Nicholas Riccobono, Scott Parks, Albert Liu

Biomedical Engineering

This report outlines the design and building process for an interchangeable testing device that collects aircraft performance data. Included is the project objectives, system requirements, management plan, design concept development, design details, manufacturing procedures, and project verification test plans. The device is a wing-mounted Pitot-static system integrated with an Electronic Flight Instrument System (EFIS).

Aperture Coupled Microstrip Antenna Design And Analysis, Michael Paul Civerolo

Master's Theses

A linearly-polarized aperture coupled patch antenna design is characterized and optimized using HFSS antenna simulation software. This thesis focuses on the aperture coupled patch antenna due to the lack of fabrication and tuning documentation for the design of this antenna and its usefulness in arrays and orthogonally polarized communications. The goal of this thesis is to explore dimension effects on aperture coupled antenna performance, to develop a design and tuning procedure, and to describe performance effects through electromagnetic principles.

Antenna parameters examined in this study include the dimensions and locations of the substrates, feed line, ground plane coupling slot, and …

High Voltage Switched-Mode Power Supply For Three-Phase Ac Aircraft Systems, John Brewer Jr., Kamaljit Bagha

Electrical Engineering

The purpose of this senior project was to design and fabricate a proof-of-concept Three-Phase Sinusoidal Switched-Mode Inverter with a power output capability of 10 kW and nominal operating frequency of 400 Hz for AC aircraft system applications. This senior project report includes a thorough discussion and presentation of the inverter system background, requirements, design, construction, and testing processes.

Ultrasonic Listener: Microcontroller Based Frequency Shifter, Troy Fredriks

Electrical Engineering

No abstract provided.

An Expandable Micromotor Dc Drive System, Michael Ruelan, Justin Gragg

Electrical Engineering

This report documents the design phases and fabrication of an expandable micro-motor DC drive system. This project illustrates that a flexible range of output power demands can be met from a small DC micro-motor drive unit with the use of power electronics.

In this project miniature DC micromotor drives, each capable of drawing up to 5.5 amps rated current (5 amps due to the utilization of a 5 amp fuse), were designed as card inserts that can be conveniently inserted in parallel in to a cardholder within the console. The “insert” feature allowed our console to successfully draw up to …

Electric Bicycle System, Robert Cong, Rodney Martinez, Mark Casilang, Peter Vong

Electrical Engineering

The Electric Bicycle System is a systems project that incorporates three different ways of charging a lithium-ion battery: the 120VAC wall outlet, regenerative braking, and solar power; which is used to power an electric hub motor running a bicycle. The purpose of the project is to show that it is possible and relatively simple, to build an electric bicycle by oneself. This project can be broken down into five separate categories: the lithium-ion battery, the DC-DC boost converter, the solar panel, the motor, and the motor controller. Each of these will be built upon and improved further by future students, …

Magnetic Design Web Application, Michael Brim

Electrical Engineering

The automated Magnetic Design Web Application, available at http://www.magneticdesign.org, generates the full design process of a power transformer, gapped inductor and toroidal inductor given design specifications provided by the user. Calculations are accomplished using Area Product, Ap, or Core Geometry, Kg, procedures. All design processes mirror the format used in Dr. Taufik’s Introduction to Magnetic Design lecture-notes. An administrative backend is provided where instructors can add or modify core design values to expand the array of materials used. The project aims to aid student understanding of magnetic design and course concepts while allowing instructors to broaden the scope of material …

Design Of A High-Low Unipolar Pulse Width Modulated Inverter, Danny Li, Christian Ramos

Electrical Engineering

This senior project report describes the process of designing a unipolar inverter. This high low, unipolar inverter utilizes switches in which a pair operates in high frequency while a second pair operates in low frequency. The purpose of this project is to convert a range of high DC voltage and convert it to an AC output voltage of 120 Vrms with a power rating of 100 W. Nonetheless, this particular unipolar method of implementing pulse width modulation results in harmonics at multiples of the fundamental frequency leading to easier filtering. However, the switching loss increases because of the complex switching …

Single-Ended Tube-Based Guitar Amplifier, Joseph (Joe) Linn

Electrical Engineering

Since the advent of the transistor, the vast majority of designers and manufacturers of electronic devices have abandoned the vacuum tube. Compared to transistors, tubes are orders of magnitude larger, more power hungry, more expensive, less reliable, and dissipate much more heat. In short, transistors are superior devices for almost all applications. Despite this fact, many makers of high-end audio and instrument amplifiers continue to base their designs on tube technology.

Given all of their shortcomings, the obvious question is: Why bother with tubes? Proponents of tube-based audio amplifiers cite a certain “warmth” that tube circuitry lends to the sound …

Energy Harvesting From Exercise Machines: Bike Buck-Boost Converter, Monroe Diamond, Brian Vuong

Electrical Engineering

This project is a continuation of previous senior projects’ work on Energy Harvesting from Exercise Machines (EHFEM). EHFEM seeks an alternative DC to DC converter to function within the existing exercise bike system. Implementing this new DC to DC converter aims to avoid previous complications other groups encountered, such as only running at low load currents, exceeding an input threshold voltage to begin operation, and performing at low efficiency. In developing this self‐generating exercise bike, Cal Poly wishes to incorporate an array of energy‐harvesting exercise machines in its Recreation Center expansion scheduled for completion in 2012.

Circular Polarized Splatch Antenna, Cynthia Truong

Electrical Engineering

The Splatch Antenna combines excellent performance and cost-effectiveness into an antenna package that can be integrated. The goal of this project is to figure out how to connect two Splatch antennas to realize a Circular Polarized (CP) antenna. The advantage of CP versus linear polarization is that CP eliminates polarization mismatch losses caused by Faraday’s rotation.

Polyenvi, Stephen Beard, Josh Engel, Paul Fake, Diego Flores, Alvaro Nunez, Miguel Wong

Electrical Engineering

Poor indoor air quality is a problem that is recognized by the Environmental Protection Agency (EPA) to cause health issues. In order to raise awareness of this problem, this document outlines the construction of a device that economically measures air quality through five metrics: dust, smoke, ozone, humidity, and temperature. The device integrates with a router to provide users access to information about their indoor air quality anywhere over the internet as well as local access to the data via an LCD mounted on the router. By increasing indoor air quality awareness, this device will aid users in making adjustments …

Ofdm Simulation In Matlab, Paul Guanming Lin

Electrical Engineering

The objective of this project is to demonstrate the concept and feasibility of an OFDM system, and investigate how its performance is changed by varying some of its major parameters. This objective is met by developing a MATLAB program to simulate a basic OFDM system. From the process of this development, the mechanism of an OFDM system can be studied; and with a completed MATLAB program, the characteristics of an OFDM system can be explored.

Simulation Of Cal Poly Super System Simulink Model Using Insolation Variation, Jacob Kory

Electrical Engineering

This senior project focuses on simulation of the Cal Poly SuPER system using an insolation model. First, local and historical weather data is examined to determine the range of limits that the model will utilize. Then, the insolation model is constructed to fit into the existing SuPER model. The overall system is tested under a variety of insolation values to determine system performance of motor and static loads. Based on these simulations, several factors of the current model are discovered that limit the power consumption profile under off-peak load conditions. Finally, recommendations on improvements to the model are discussed

Micro Forest Fire Detection, John Cape

Electrical Engineering

No abstract provided.

Power Losses Associated With Stand-By Chargers, Robert Peralta

Electrical Engineering

Many average households across the United States may not realize how much power is saved by simply removing the plug from the receptacle when not being used. A misconception with stand-by/portable chargers is; if a device is not connected to the charger, but the charger is still connected to the wall, then the charger will not consume power. That statement is false. The following report will demonstrate how much power is lost in an average household. When a reference is made to an average house, I will refer to a 4 bedroom single family home. The house will have an …

Transmission Line Forecast Study, Ryan Garoogian

Electrical Engineering

Load forecasting is the procedure to predict future loading conditions on a power system. Using simulation software such as ETAP you are able to predict abnormal voltage conditions, overloading of certain equipment, as well as determine protective equipment from short circuit studies. This study consisted of a 115kV loop network with multiple loading busses and one infinite bus. There was no separate generation other than the infinite bus. As load increased from forecasting to the future voltage dropped. To restore voltage levels capacitors were added at strategic points in the system to boost the voltage back up. Preparing yourself for …

Energy Harvesting From Exercise Machines Cal Poly Recreation Center Implementation, Justin Arakaki, Praveen Lawrence, Audrey Nakamura

Electrical Engineering

As Cal Poly moves towards an environmentally friendly campus, the Energy Harvesting from Exercise Machines (EHFEM) project looks to generate a new source of renewable energy to help power the Cal Poly Recreation Center. The project focuses on retrofitting exercise machines to generate electricity. As of December 2009, Audrey Nakamura, Justin Arakaki, and Praveen Lawrence developed a design which allows the contribution of electricity generated from multiple exercise machines into the power grid.

The project will require an investigation of retrofitted machine designs by Cal Poly students and commercially available products and systems. The information obtained from the product research …

Class-D Power Amplifier, Joseph Maldonado, Jeovany Vega

Electrical Engineering

No abstract provided.

Uav Pirates And Silentrack Integration, Travis Dean, Hushnak Singh, Ashley Wager, Matthew (Matt) Woolridge

Electrical Engineering

The integration of the UAV pirating system with the SilenTrack video tracking system will allow the combined system to automatically identify and track a suspicious air vehicle visually as well as identify and decode the RF control signal. Once a threat has been identified, the system will execute an algorithm to associate each control channel with the corresponding flight control surface. Once the control channels have been decoded the user can use a hand held radio controller to maneuver the drone which is now under their command.

Negative Conductance Load Modulation Rf Power Amplifier, Cody R. Neslen

Master's Theses

The number of mobile wireless devices on the market has increased substantially over the last decade. The frequency spectrum has become crowded due to the number of devices demanding radio traffic and new modulation schemes have been developed to accommodate the number of users. These new modulation schemes have caused very poor efficiencies in power amplifiers for wireless transmission systems due to high peak-to-average power ratios (PAPR). This thesis first presents the issue with classical power amplifiers in modern modulation systems. A brief overview of current attempts to mitigate this issue is provided. A new RF power amplifier topology is …

Touch Screen Sound Controller, James Fenley, Jonathan Law

Electrical Engineering

The Touch Screen Sound Controller sets out to explore the use of a touch screen as a sound control interface for the disk jockey profession. In addition, the project aims to provide an alternate means of transferring audio data by way of TCP/IP communications as opposed to MIDI. By applying our method, a user may stream pulse-code modulated data from a server onto a client’s RAM via an Ethernet connection. A 32bit, 200MHz ARM9 microprocessor addresses data from the RAM and proceeds with executing DSP instructions from the user. The connection between the touch screen and the central microprocessor is …

Fm Radio Receiver With Digital Demodulation, Nicholas Burnett

Electrical Engineering

This paper reports on the design, construction, and testing of an FM receiver. The design is split into two portions, the analog FM front end and the digital demodulator. The job of the front end is to down convert the RF signal to a frequency that is low enough to sample with an analog to digital converter. The construction of the front end is done using what is known as “Ugly Construction.” That is, all the components are soldered together floating over a ground plane.

The second portion of the design is the demodulator. The phase lock loop method of …

Sign Language Glove, Nicholas Born

Electrical Engineering

Between 500,000 and 2 million Americans use American Sign Language (ASL) as their primary language. As such, a device capable of translating those movements into text would be useful in many areas, such as teaching and the entertainment industry.

The goal of this project was to show that the creation of a glove device that takes in sign language letters, interprets them into the desired characters, and can input those characters into a computer is feasible. I chose to work on this project for many different reasons. One reason is many members of my family know sign language and use …

Standalone Antenna Demonstration System, Alexander James Hempy

Master's Theses

Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill interest in the field of antenna design among high school and undergraduate college students. The system is portable, supplied solely by DC power supplies, easily reproducible, and includes rotational axes to illustrate antenna performance limitations and requirements. It provides a visual indication of wireless signal strength and demonstrates several antenna performance characteristics including polarization, gain and directivity, radiation patterns …

A Constant Conduction Angle Biased Rf Power Amplifier For Improved Linearization In Class C Operation, Greg Lacaille

Master's Theses

Class C power amplifiers offer higher efficiency than class B power amplifiers, but suffer from poor linearity. A feedback based biasing system to improve the linearity of a class C power amplifier is designed. A class B amplifier with a gain of 20 dB and 20 MHz bandwidth at 900 MHz acts as the launching point for the design. The biasing and output network of the class B power amplifier is modified to produce a class C amplifier at conduction angles of 180°, 162°, 126°, 90°, and 54°. A feedback based biasing system, which uses two matched and scaled down …

Improved Rf Power Extraction From 1.55um Ge-On-Soi Pin Photodiodes With Load Impedance Optimization, Andrew L. Huard

Master's Theses

VLSI miniaturization has created the need for high-density, low-cost, monolithically-integrated optical interconnects. High output power photodetectors are needed to directly drive load circuitry, which improves the noise performance and dynamic range of optical communications links by eliminating a post amplifier stage. Elimination of the post amplifier also reduces circuit cost and complexity. A new Si-Ge PIN waveguide photodiode with 31GHz bandwidth and 93% quantum efficiency at 1550nm has been developed by Yin et al., which was fabricated using standard CMOS processes on a Silicon substrate. This thesis demonstrates a method for improving the RF power extraction from these photodiodes by …

Wave Energy Converter Performance Modeling And Cost Of Electricity Assessment, Dmitri Jarocki

Master's Theses

California is experiencing a rapid increase in interest for the potential of converting ocean waves into clean electricity. Numerous applications have been submitted for the permitting of such renewable energy projects; however the profitability, practicability, and survivability have yet to be proven. Wave energy conversion technology has steadily matured since its naissance in the 1970’s, several wave energy power installations currently exist, and numerous plans for commercial power plant are in the works on the shores of multiple continents. This study aims to assess the economic viability of two proposed commercial wave energy power plant projects on the Central California …

Space-Time Adaptive Processing With Multi-Staged Wiener Filter And Principal Component Signal Dependent Algorithms, Zheng N. Zhou

Master's Theses

Space-time Adaptive Processing (STAP) is a two-dimensional filtering technique for antenna array with multiple spatial channels. The name "space-time" describes the coupling of these spatial channels with pulse-Doppler waveforms. Applications for STAP includes ground moving target indicator (GMTI) for airborne radar systems.

Today, there are strong interests to develop STAP algorithms for operations in “sample starved” environments, where intense environmental interference can reduce STAP capacity to detect and track ground targets. Careful applications of STAP can effectively overcome these conditions by suppressing these interferences and maximize the signal to interference plus noise ratio (SINR). The Multi-stage Wiener filter (MWF) and …