Engineering Commons^™

"Auto-Tuned" Stereo, Daniel Montes

Electrical Engineering

The purpose of this project is to determine the capability of introducing delay and gain to audio signals to synthesize a “tuned” experience. The project uses audio operational amplifiers, field effect transistors, a class D amplifier, microphones, speakers, a 32-bit microcontroller for design and testing. When implementing the MOSFET into the all pass filter, the phase delay occurs by varying the transistor resulted in minimal change in phase. MOSFETs are used as variable resistors to vary the phase change and gain. By modifying the gain the synthesized distance from each speaker can be adjusted. Varying the phase change provides the …

Lyfi, Kianoosh Salami, Justin Cotton, Elush Shirazpour

Electrical Engineering

This paper will cover the steps necessary to design, build, and manage networkable smart light switches over WiFi via a mobile application. It contains a microcontroller running a real time operating system, a WiFi module, a Java server with SQLite databasing, and a mobile phone application.

LyFi is designed to turn on/off and dim household lights while only requiring the same installation procedure as a less capable dimmer switch. Once installed and connected to a network, LyFi will self-discover and configure. The server automatically propogates a database of nodes where any mobile device running an application can receive an updated …

Inductive Metal Identification, Paul Maggi

Electrical Engineering

This project focuses on creating a device to differentiate between various types of metals via magnetic induction. Magnetic induction is used because it is both non-optical and non-contact. It achieves this by generating a varying magnetic field, which induces eddy currents in the metal. These eddy currents produce small disturbances in the surrounding magnetic field, which can be sensed with Hall Effect Sensors (HES). The primary challenge in this project was generating a sufficiently strong magnetic field to detectable disturbances. In order to achieve better results, a stronger magnetic field must be used as well as more sensitive Hall Effect …

Portable Solar Powered Charging Station, Jordan Bonner

Electrical Engineering

The portable solar powered charging station uses a solar powered mat that can be folded for portability. The device has the ability to charge small electronics during both day and night. When sunlight is available, the charger charges two C batteries in series and at the same time it charges any electronic device that can be connected via USB or cigarette lighter. At night the charger will charge the same electronic devices from the onboard batteries. The charging station must be able to interface with electronic devices using USB and a car cigarette lighter to charge the device’s battery.

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 …

Design And Simulation Of Interconnected H-Bridge Inverter, Samuel Muehleck

Computer Engineering

In this project, the research, design and simulation of an interconnected H-bridge single-phase inverter was explored. The inverter design was divided into three separate sections. First, a VHDL programmed CPLD was used to generate control signals for the transistors of the inverter circuit. Second, power electronics was used to create an inverter circuit to change a DC input to a 60 Hz AC output. Lastly, additional circuits were used to link the generated control signals to the MOSFET transistors of the inverter circuit. The operation of the three components was then validated with computer simulations. Results of computer simulation demonstrate …

Design, Construction, And Evaluation Of An Automated Chicken Coop Door, Kyle Inks

BioResource and Agricultural Engineering

This senior project takes a look into the design, construction, and evaluation of an automated chicken coop door. The idea and need for such a door came from my mother Jan Inks. The parameters for the project include, low production cost, easy installation on existing coops, sleek design, automatically open at a set time in the morning, and automatically close at a set time in the evening.

Surveying First-Year Students Prior Conceptual Understanding Of Direct Current Resistive Electric Circuits: An Update, Aidan O'Dwyer

Conference papers

There is an increasing diversity of educational background of students entering Level 7 and Level 8 programmes in engineering in Irish third level education. Student reasoning about basic electricity concepts often differs from accepted explanations. The paper reports, analyses and reflects on the results of a multiple-choice diagnostic test to assess student understanding of such concepts (developed by Engelhardt and Beichner (2004) for U.S. high school and college students) taken by four cohorts of students, on the same DIT Level 7 engineering programme, from 2008-12 (n=106) and two cohorts of students, on the same DIT Level 8 engineering programme, from …

Cell Phone Charger For The Dc House Project, Andrew Hefner, Antonio Magdaleno

Electrical Engineering

The goal of this project is to create a multiple output cell phone charger for the DC House project. The cell phone charger is essentially a DC-DC converter. The converter takes an input of 48 volts from the outlet in the DC House and decreases the voltage level to 5 volts; the input voltage level of all cellular devices. By designing an isolated flyback converter with initial specification in LTSpice simulation software, a converter was created. By monitoring the input and output voltage and current using the multi-meters and electronic load, we determined the charger to be 71% efficient when …

All-In-One Aprs Transmitter, Justin Kenny

Electrical Engineering

The Automatic Packet Reporting System (APRS) is a digital radio system that allows transmission of data using an analog FM radio link. APRS allows position, brief messages, and other data to be distributed across a network, independent of infrastructure, making it ideal for applications such as search and rescue, asset management, and event tracking, while maintaining low cost and operating even when cellular and internet services are unavailable. This project encompasses the design, build, and test of a compact, low-cost APRS transmitter, which will include a 5W radio, GPS, and LCD-based user interface, to allow full utilization of APRS.

Ignitron Trigger Circuit, John F. O'Hara Iii

Electrical Engineering

No abstract provided.

Pulsed Class-G Rf Amplifier System, Kevin Maulhardt, Kevin Haskett

Electrical Engineering

No abstract provided.

12 Volt Wall Outlet For The Dc House Project, Dylan Van Lant, Chenxi Zhang

Electrical Engineering

The purpose of this project is to build a DC-DC converter for the wall outlet of the DC House. This report focuses on the development of the DC -DC converter, and explains the design process as well as summarize the final results. The proposed system using the Buck or Step Down topology takes input voltage of 48V and output 12V at 100W. Results show the ability of the converter to fulfill such tasks while maintaining efficiency about 90% at all load.

Music Driven Graphical Visualization System, Glenn Bruner

Electrical Engineering

In today’s society, we are able to enjoy listening to music on an assortment of high-tech devices such as home computers, or multimedia players, or personal audio players. A common characteristic of typical audio media players is that they lack the ability to provide visual stimulation in addition to the provided audio stimulus. Large public events, such as concerts, could be enhanced if they included visual effects in addition to audio stimulation. The goal of this project is to provide a graphical visualization that is automatically synchronized to an audio signal with a goal of enhancing the overall musical experience. …

Foce Intermodule Communications System, Roland Quiros

Electrical Engineering

Done in conjunction with Chad Kecy of the Monterey Bay Aquarium Reasearch Institute (MBARI), this project is an expansion of the Free Ocean Carbon Emission (FOCE) project. This iteration created a communications protocol between the different modules in an expandable array of PIC24-based boards.

Day/Night Band Imager For A Cubesat, Eric Stanton

Electrical Engineering

Day/Night Band (DNB) earth sensing and meteorological systems like the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) provide visible wavelength imagery 24 hours a day that is used primarily for cloud imaging in support of weather forecasting. This paper describes a compact push-broom imager that meets low light imaging requirements for DMSP OLS and the NOAA/NASA Joint Polar Satellite System (JPSS) as documented in the Integrated Operational Requirements Document [1] (IORD) including the imager design, system level concepts of operation for data collection, radiometric and spatial calibration, and data transmission to Earth. This small, lightweight imager complies with …

Energy Harvesting From Elliptical Machines: Dc-Dc Converter Design Using Sepic Topology, Martin Kou

Master's Theses

Cal Poly’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project is a very convenient and cost-effective way for generating DC power from physical exercise and sending it back to the electrical grid as AC power, providing a renewable energy source for the future. The EHFEM project consists of numerous subprojects involving converting different types of exercise machines for power generation. This project is a continuation of one of the previous subprojects, specifically involving an elliptical machine, and focuses on improving system functionality at different machine settings without altering the elliptical user’s experience by selecting a new DC-DC converter design, while …

Cascaded High Voltage Converter With Variable Control For Pulsed Electric Field Applications, Emmanuel Loza

Master's Theses

Living a sustainable lifestyle while facing increasing population and decreasing natural resources has become one of humanity’s largest challenges. Locating fossil fuels is becoming more difficult while the demand for them to power our societies is ever increasing. Instead of finding more efficient methods of extracting fossil fuels, developing technologies that create renewable substitutes for fossil fuels is now the strategy. Algae biofuel matches fossil fuel performance while also meeting the criteria for renewable energy. The focus now shifts to finding methods for commercially producing algae biofuel. Therefore, the objective of this thesis is to develop a system that provides …

Linear Power-Efficient Rf Amplifier With Partial Positive Feedback, Matthew E. King

Master's Theses

Over the last decade, the number of mobile wireless devices on the market has increased substantially. New “multi-carrier” modulation schemes, such as OFDM, WCDMA, and WiMAX, have been developed to accommodate the increasing number of wireless subscribers and the demand for faster data rates within the limited commercial frequency spectrum. These complex modulation schemes create signals with high peak-to-average power ratios (PAPR), exhibiting rapid changes in the signal magnitude. To accommodate these high-PAPR signals, RF power amplifiers in mobile devices must operate under backed-off gain conditions, resulting in poor power efficiency. Various efficiency-enhancement solutions have been realized for backed-off devices …

Design, Modeling And Fabrication Of Shear Mode Bulk Acoustic Wave Sensor As A Potential Biosensor, Chi-Jung Cheng

Dissertations

There has been an increasing interest in development of thin film bulk acoustic wave resonator (FBAR) devices for chemical and biological sensing applications in the environmental and biomedical industries. The zinc oxide (ZnO) thin film based FBAR devices provides attractive advantages, such as high resonant frequency, small size, and rapid response. Typically, the ZnO-based FBAR devices are operated in the longitudinal wave mode where the ZnO crystallites are perpendicular to the substrate. In gaseous environments, the longitudinal mode FBAR device provides high sensitivity for mass sensing. However, the longitudinal wave mode is adversely affected when used in liquid environments because …

A Study Of Integrated Uwb Antennas Optimised For Time Domain Performance, Antoine Dumoulin

Doctoral

Antennas for impulse radio ultra-wideband based portable devices are required to be compact and able to transmit or receive waveforms with minimal distortion in order to support proximity ranging with a centimetre-scale precision. The first part of thesis characterises several pulse types for use in the generation of picosecond-scale signals in respect to the regulatory power and frequency standards while the principles of antenna transient transmission and reception are stated. The proximity effect of planar conductors on the performance of an ultra-wideband antenna is investigated in both spectral and temporal domain demonstrating the relationship between the antenna-reflector separation and the …

Driver Behavior Classification And Lateral Control For Automobile Safety Systems, Jing Yang

Dissertations

Advanced driver assistance systems (ADAS) have been developed to help drivers maintain stability, improve road safety, and avoid potential collision. The data acquisition equipment that can be used to measure the state and parameter information of the vehicle may not be available for a standard passenger car due to economical and technical limitations. This work focuses on developing three technologies (longitudinal tire force estimation, driver behavior classification and lateral control) using low-cost sensors that can be utilized in ADAS.

For the longitudinal tire force estimation, a low cost 1Hz positioning global system (GPS) and a steering angle sensor are used …

Advanced Intelligent Control And Optimization For Cardiac Pacemaker Systems, Wei Shi

Dissertations

Since cardiovascular diseases are major causes of morbidity and mortality in the developed countries and the number one cause of death in the United States, their accurate diagnosis and effective treatment via advanced cardiac pacemaker systems have become very important. Intelligent control and optimization of the pacemakers are significant research subjects. Serious but infrequently occurring arrhythmias are difficult to diagnose. The use of electrocardiogram (ECG) waveform only cannot exactly distinguish between deadly abnormalities and temporary arrhythmias. Thus, this work develops a new method based on frequency entrainment to analyze pole-zero characteristics of the phase error between abnormal ECG and entrained …

Energy Harvesting-Aware Design Of Wireless Networks, Fabio Iannello

Dissertations

Recent advances in low-power electronics and energy-harvesting (EH) technologies enable the design of self-sustained devices that collect part, or all, of the needed energy from the environment. Several systems can take advantage of EH, ranging from portable devices to wireless sensor networks (WSNs). While conventional design for battery-powered systems is mainly concerned with the battery lifetime, a key advantage of EH is that it enables potential perpetual operation of the devices, without requiring maintenance for battery substitutions. However, the inherent unpredictability regarding the amount of energy that can be collected from the environment might cause temporary energy shortages, which might …

Auger-Mediated Processes And Photoluminescence In Group Iv Semiconductor Nanostructures, Nikhil Modi

Dissertations

Group IV semiconductors (Si, Ge) are inefficient light emitting materials due to their indirect bandgap structure. Nanostructures of Si, Ge, and SiGe however, have shown relatively high photoluminescence (PL) quantum efficiency (QE) at low carrier concentrations. At higher carrier concentrations, the PL QE of these nanostructures is drastically reduced due to the onset of a fast non-radiative process attributed to Auger recombination. Moreover, this onset occurs earlier in structures with reduced physical dimensions, than in bulk material. The study of Auger-mediated processes in group IV nanostructures is therefore critical to understanding the physics of carrier recombination and photonic device limitations. …

Image Statistical Frameworks For Digital Image Forensics, Patchara Sutthiwan

Dissertations

The advances of digital cameras, scanners, printers, image editing tools, smartphones, tablet personal computers as well as high-speed networks have made a digital image a conventional medium for visual information. Creation, duplication, distribution, or tampering of such a medium can be easily done, which calls for the necessity to be able to trace back the authenticity or history of the medium. Digital image forensics is an emerging research area that aims to resolve the imposed problem and has grown in popularity over the past decade. On the other hand, anti-forensics has emerged over the past few years as a relatively …

Three-Dimensional Magnetic Field Sensor In Ibm 0.18Μm Cmos Technology, Gang Wang

Theses

This work presents a compact three-dimensional Magnetic Field Sensor (MFS) designed in standard Complementary Metal-Oxide-Semiconductor (CMOS) technology. A circular Vertical Hall Device (VHD) for horizontal magnetic field detection and a split- drain Horizontal Hall Device (HHD) for the vertical magnetic field detection are integrated to implement the three-dimensional M FS. This merged design has the advantage of smaller area and lower power consumption. The sensitivity of the vertical hall device (ring-shaped magneto-resistor) and the horizontal hall device (Split-Drain Magnetic Field-Effect Transistor (SD-MAGFET)) is estimated as 0.11V/T and 2.88V/T respectively. The vertical direction of the magnetic field detection demonstrates a higher …

Moxon Based Rfid Tag Reader And Gps Antenna, Haojiong Liu

Theses

Modern communication applications at UHF frequencies require antennas with wide band, high forward gain, low backward radiation, high cross-polarization, small size and low manufacture cost. The Moxon antenna based on a two element Yagi-Uda antenna over the ground reflector is one of the most favorite antennas for HAM operators which can produce outstanding front to back ratio of radiated power, good match over the desired band and relatively low elevation height.

A sequence of topologies has been proposed from a single vertical element to two vertical elements of the Moxon arms, until the lately patented Broadband Circularly Polarized Moxon Based …

Antipodal Vivaldi Antenna For Water Pipe Sensor And Telemetry, Giuseppe Ruvio, Domenico Gaetano, Max Ammann, Patrick Mcevoy

Articles

An antipodal Vivaldi antenna operates simultaneously for telemetry and sensing when placed conformally onto PVC pipes. Good radiation efficiency is realised and the antenna impedance matching remains stable when the pipe is empty or contains water. The Fidelity Factor performance based on an input Ultra Wideband Gaussian pulse is a suitable figure of merit to detect water presence. Different water levels and pipe conditions correspond to Fidelity Factors between 90% and 96%, which are a suitable dynamic range for sensing and the appropriate quality for pulse communications for remote monitoring.

Performance Comparison Of A Permissive Overreach Transfer Trip (Pott) Scheme Over Iec 61850 And Hard-Wire, José Luis Ruiz

Masters Theses and Doctoral Dissertations

The International Electrotechnical Commission (IEC) 61850 is a standard that allows communication integration of systems built from multivendor power protection relays. The standard describes the rules for integration of control, measurement, and protection functions within a power system network at the substation control levels. The standard was created with the idea of eliminating wiring in the substation and facilitating the communication between different relay vendors. This study implemented IEC 61850 standard in a Permissive Overreach Transfer Trip (POTT) scheme to protect a 166 mile, 230 kV transmission line using Generic Object Oriented Substation Events (GOOSE) messaging in the laboratory. Two …