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Description
Buck converters are a class of switched-mode power converters often used to step down DC input voltages to a lower DC output voltage. These converters naturally produce a current and voltage ripple at their output due to their switching action. Traditional methods of reducing this ripple have involved adding large

Buck converters are a class of switched-mode power converters often used to step down DC input voltages to a lower DC output voltage. These converters naturally produce a current and voltage ripple at their output due to their switching action. Traditional methods of reducing this ripple have involved adding large discrete inductors and capacitors to filter the ripple, but large discrete components cannot be integrated onto chips. As an alternative to using passive filtering components, this project investigates the use of active ripple cancellation to reduce the peak output ripple. Hysteretic controlled buck converters were chosen for their simplicity of design and fast transient response. The proposed cancellation circuits sense the output ripple of the buck converter and inject an equal ripple exactly out of phase with the sensed ripple. Both current-mode and voltage-mode feedback loops are simulated, and the effectiveness of each cancellation circuit is examined. Results show that integrated active ripple cancellation circuits offer a promising substitute for large discrete filters.
ContributorsWang, Ziyan (Author) / Bakkaloglu, Bertan (Thesis director) / Kitchen, Jennifer (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
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Description
The world of a hearing impaired person is much different than that of somebody capable of discerning different frequencies and magnitudes of sound waves via their ears. This is especially true when hearing impaired people play video games. In most video games, surround sound is fed through some sort of

The world of a hearing impaired person is much different than that of somebody capable of discerning different frequencies and magnitudes of sound waves via their ears. This is especially true when hearing impaired people play video games. In most video games, surround sound is fed through some sort of digital output to headphones or speakers. Based on this information, the gamer can discern where a particular stimulus is coming from and whether or not that is a threat to their wellbeing within the virtual world. People with reliable hearing have a distinct advantage over hearing impaired people in the fact that they can gather information not just from what is in front of them, but from every angle relative to the way they're facing. The purpose of this project was to find a way to even the playing field, so that a person hard of hearing could also receive the sensory feedback that any other person would get while playing video games To do this, visual surround sound was created. This is a system that takes a surround sound input, and illuminates LEDs around the periphery of glasses based on the direction, frequency and amplitude of the audio wave. This provides the user with crucial information on the whereabouts of different elements within the game. In this paper, the research and development of Visual Surround Sound is discussed along with its viability in regards to a deaf person's ability to learn the technology, and decipher the visual cues.
ContributorsKadi, Danyal (Co-author) / Burrell, Nathaneal (Co-author) / Butler, Kristi (Co-author) / Wright, Gavin (Co-author) / Kosut, Oliver (Thesis director) / Bliss, Daniel (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2015-05
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Description
Current technology does not allow for the full amount of power produced by solar arrays (PV) on spacecraft to be utilized. The arrays are designed with non-reconfigurable architectures and sent on fifteen to twenty year long missions. They cannot be changed once they are in space, so the arrays are

Current technology does not allow for the full amount of power produced by solar arrays (PV) on spacecraft to be utilized. The arrays are designed with non-reconfigurable architectures and sent on fifteen to twenty year long missions. They cannot be changed once they are in space, so the arrays are designed for the end of life. Throughout their lifetime, solar arrays can degrade in power producing capabilities anywhere from 20% to 50%. Because there is such a drastic difference in the beginning and end of life power production, and because they cannot be reconfigured, a new design has been found necessary in order to increase power production. Reconfiguration allows the solar arrays to achieve maximum power producing capabilities at both the beginning and end of their lives. With the potential to increase power production by 50%, the reconfiguration design consists of a switching network to be able to utilize any combination of cells. The design for reconfiguration must meet the power requirements of the solar array. This thesis will explore different designs for reconfiguration, as well as possible switches for implementation. It will also review other methods to increase power production, as well as discuss future work in this field.
ContributorsJohnson, Everett Hope (Author) / Kitchen, Jennifer (Thesis director) / Ozev, Sule (Committee member) / School of International Letters and Cultures (Contributor) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
A novel strain sensing procedure using an optical scanning methodology and diffraction grating is explored. The motivation behind this study is due to uneven thermal strain distribution across semiconductor chips that are composed of varying materials. Due to the unique properties of the materials and the different coefficients of thermal

A novel strain sensing procedure using an optical scanning methodology and diffraction grating is explored. The motivation behind this study is due to uneven thermal strain distribution across semiconductor chips that are composed of varying materials. Due to the unique properties of the materials and the different coefficients of thermal expansion (CTE), one can expect the material that experiences the highest strain to be the most likely failure point of the chip. As such, there is a need for a strain sensing technique that offers a very high strain sensitivity, a high spatial resolution while simultaneously achieving a large field of view. This study goes through the optical setup as well as the evolution of the optical grating in an effort to improve the strain sensitivity of this setup.
ContributorsChen, George (Co-author) / Ma, Teng (Co-author) / Liang, Hanshuang (Co-author) / Song, Zeming (Co-author) / Nguyen, Hoa (Co-author) / Yu, Hongbin (Thesis director) / Jiang, Hanqing (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
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Description
Electroencephalogram (EEG) used simultaneously with video monitoring can record detailed patient physiology during a seizure to aid diagnosis. However, current patient monitoring systems typically require a patient to stay in view of a fixed camera limiting their freedom of movement. The goal of this project is to design an automatic

Electroencephalogram (EEG) used simultaneously with video monitoring can record detailed patient physiology during a seizure to aid diagnosis. However, current patient monitoring systems typically require a patient to stay in view of a fixed camera limiting their freedom of movement. The goal of this project is to design an automatic patient monitoring system with software to track patient movement in order to increase a patient's mobility. This report discusses the impact of an automatic patient monitoring system and the design steps used to create and test a functional prototype.
ContributorsBui, Robert Truong (Author) / Frakes, David (Thesis director) / Helms Tillery, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
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Description
This project examines the science of electric field sensing and completes experiments, gathering data to support its utility for various applications. The basic system consists of a transmitter, receiver, and lock-in amplifier. The primary goal of the study was to determine if such a system could detect a human disturbance,

This project examines the science of electric field sensing and completes experiments, gathering data to support its utility for various applications. The basic system consists of a transmitter, receiver, and lock-in amplifier. The primary goal of the study was to determine if such a system could detect a human disturbance, due to the capacitance of a human body, and such a thesis was supported. Much different results were obtained when a person disturbed the electric field transmitted by the system than when other types of objects, such as chairs and electronic devices, were placed in the field. In fact, there was a distinct difference between persons of varied sizes as well. This thesis goes through the basic design of the system and the process of experimental design for determining the capabilities of such an electric field sensing system.
ContributorsBranham, Breana Michelle (Author) / Allee, David (Thesis director) / Papandreou-Suppappola, Antonia (Committee member) / Phillips, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor) / School of International Letters and Cultures (Contributor)
Created2013-05
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Description
A hybrid PV/T module was built, consisting of a thermal liquid heating system and a photovoltaic module system that combine in a hybrid format. This report will discuss the work on the project from Fall 2012 to Spring 2013. Three stages of experiments were completed. Stage 1 showed our project

A hybrid PV/T module was built, consisting of a thermal liquid heating system and a photovoltaic module system that combine in a hybrid format. This report will discuss the work on the project from Fall 2012 to Spring 2013. Three stages of experiments were completed. Stage 1 showed our project was functional as we were able to verify our panel produced electricity and increased the temperature of water flowing in the system by 0.65°C. Stage 2 testing included “gluing” the flow system to the back of the panel resulting in an average increase of 4.76°C in the temperature of the water in the system. Stage 3 testing included adding insulating foam to the module which resulted in increasing the average temperature of the water in our flow system by 6.95°C.
ContributorsDenke, Steven Michael (Author) / Roedel, Ron (Thesis director) / Aberle, James (Committee member) / Rauch, Dawson (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2013-05
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Description
Lighting Audio is a team of senior electrical engineering students at the Arizona State University mentored by Director Emeritus Professor Ronald Roedel and 2nd Committee Member George Karady attempting to prove the feasibility of a consumer grade plasma arc speaker. The plasma arc speaker is a project that explores the

Lighting Audio is a team of senior electrical engineering students at the Arizona State University mentored by Director Emeritus Professor Ronald Roedel and 2nd Committee Member George Karady attempting to prove the feasibility of a consumer grade plasma arc speaker. The plasma arc speaker is a project that explores the use of high voltage arcs to produce audible sound amplification. The goal of the project is to prove feasibility that a consumer grade plasma arc speaker could exist in the marketplace. The inherent challenge was producing audio amplification that could compete with current loudspeakers all while ensuring user safety from the hazards of high voltage and current shock, electromagnetic damage, and ozone from the plasma arc. The project has thus far covered the process of design conception to realization of a prototype device. The operation of the plasma arc speaker is based on the high voltage plasma arc created between two electrodes. The plasma arc rapidly heats and cools the surrounding air creating changes in air pressure which vibrate the air. These pockets of pressurized air are heard as sound. The circuit incorporates a flyback transformer responsible for creating the high voltage necessary for arcing.
ContributorsNandan, Rahul S (Author) / Roedel, Ronald (Thesis director) / Huffman, James (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2014-05
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Description
Lighting Audio is a team of senior electrical engineering students at the Arizona State University mentored by Director Emeritus Professor Ronald Roedel and 2nd Committee Member George Karady attempting to prove the feasibility of a consumer grade plasma arc speaker. The plasma arc speaker is a project that explores the

Lighting Audio is a team of senior electrical engineering students at the Arizona State University mentored by Director Emeritus Professor Ronald Roedel and 2nd Committee Member George Karady attempting to prove the feasibility of a consumer grade plasma arc speaker. The plasma arc speaker is a project that explores the use of high voltage arcs to produce audible sound amplification. The goal of the project is to prove feasibility that a consumer grade plasma arc speaker could exist in the marketplace. The inherent challenge was producing audio amplification that could compete with current loudspeakers all while ensuring user safety from the hazards of high voltage and current shock, electromagnetic damage, and ozone from the plasma arc. The project has thus far covered the process of design conception to realization of a prototype device. The operation of the plasma arc speaker is based on the high voltage plasma arc created between two electrodes. The plasma arc rapidly heats and cools the surrounding air creating changes in air pressure which vibrate the air. These pockets of pressurized air are heard as sound. The circuit incorporates a flyback transformer responsible for creating the high voltage necessary for arcing.
ContributorsNandan, Rahul S (Author) / Roedel, Ronald (Thesis director) / Huffman, James (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
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Description
This paper reviews several current designs of Cube Satellite (CubeSat) Electrical Power Systems (EPS) based on Silicon FET technologies and their current deficiencies, such as radiation-incurred defects and switching power losses. A strategy to fix these is proposed by the way of using Gallium Nitride (GaN) High Electron-Mobility Transistors (HEMTs)

This paper reviews several current designs of Cube Satellite (CubeSat) Electrical Power Systems (EPS) based on Silicon FET technologies and their current deficiencies, such as radiation-incurred defects and switching power losses. A strategy to fix these is proposed by the way of using Gallium Nitride (GaN) High Electron-Mobility Transistors (HEMTs) as switching devices within Buck/Boost Converters and other regulators. This work summarizes the EPS designs of several CubeSat missions, classifies them, and outlines their efficiency. An in-depth example of an EPS is also given, explaining the process in which these systems are designed. Areas of deficiency are explained along with reasoning as to why GaN can mitigate these losses, including its wide bandgap properties such as high RDS(on) and High Breakdown Voltage. Special design considerations must be kept in mind when using GaN HEMTs in this application and an example of a CubeSat using GaN HEMTs is mentioned. Finally, challenges ahead for GaN are explored including manufacturing considerations and long-term reliability.
ContributorsWilloughby, Alexander George (Author) / Kitchen, Jennifer (Thesis director) / Zhao, Yuji (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05