Engineering Commons^™

Dc-Dc Buck-Boost Converter For Energy Harvesting From Exercise Equipment, David T. Bolla

Electrical Engineering

This senior project helps harvest the excess energy that exercise equipment generates. Sustainable energy acts as the main target for this project, and it attempts this through reusing the energy created when exercising on elliptical machines. An elliptical machine outputs voltages between approximately 5V and 60V, and a micro-inverter requires an input voltage of about 36V. This DC-DC converter takes the variable output voltage of an elliptical machine and brings it to approximately 36V. Re-purposing the excess energy an elliptical user creates for the grid provides a sustainable alternative to dissipating the energy as heat. This project, along with other …

Spread Spectrum Buck Converter, Summer Elise Rutherford, Kyle Brandon Halloran, Brian Taylor Arbiv

Electrical Engineering

Electromagnetic interference (EMI) is an issue prevalent to DC-DC converters. When a system doesn’t effectively filter out external noise or signals, these signals can cause disturbances to the system at large. The switching technology of DC-DC converters (PWM in particular), lends the system susceptible to EMI because there is a prevalent peaks at the switching frequency, meaning any external signals will not be effectively attenuated at this frequency. This can cause significant issues at the input bus of the DC-DC converters because this bus is likely the input of a multitude of devices; the EMI susceptibility caused by switching technology …

Multiple Input, Single Output Dc-Dc Conversion Stage For Dc House, Jason Baltierrez

Master's Theses

n this thesis project, a proposed architecture for the multiple input, single output conversion stage for the DC House was designed, simulated, and tested. This architecture allows for multiple different input sources to be used to create a single higher power output source. The design uses a DC-DC boost converter with a parallelable output which has been demonstrated to allow increased total output power as a function of the number of input sources available. The parallelable output has been shown to distribute load amongst the input sources relatively closely to optimize the system. This approach is also desirable since it …

Analog Single Sideband-Pulse Width Modulation Processor For Parametric Acoustic Arrays, Vikrant A. Marathe

Master's Theses

Parametric acoustic arrays are ultrasonic-based loudspeakers that produce highly directive audio. The audio must first be preprocessed and modulated into an ultrasonic carrier before being emitted into the air, where it will self-demodulate in the far field. The resulting audio wave is proportional to the double time-derivative of the square of the modulation envelope. This thesis presents a fully analog processor which encodes the audio into two Pulse Width Modulated (PWM) signals in quadrature phase and sums them together to produce a Single Sideband (SSB) spectrum around the fundamental frequency of the PWM signals. The two signals are modulated between …

Dc To Dc Usb-C Charger, Nikki Gmerek, Kenneth Nguyen, Uriel Serna

Electrical Engineering

The DC House USB-C Charger will convert the 48V input from the DC house, found on the Cal Poly campus, to 3 USB-C outputs: 5V, 12V, and 24 volts. The converter will deliver a total of 185 Watts out across all 3 outputs, with an efficiency greater than 82% at full load. The USB-C ports will be used to connect to compatible phones, laptops or any other device for charging/powering purposes. The goal of this project is to develop the most efficient and safe converter to deliver power to multiple outputs using USB-C, for items as small as a cell …

Underwater Remotely Operated Vehicle Controller With Pid Stability Regulation, Christian E. Aguirre

Electrical Engineering

The earth’s oceans and rivers remain widely unexplored. Hobbyists and companies across the globe invest money and resources into remotely operated vehicles (ROV) to further expand underwater knowledge. Each ROV includes a controller that operates motors and monitors other crucial system vitals. The ROV Controller project makes the process of designing an ROV simpler and more affordable by providing a multi-purpose programmable controller.

The ROV controller features programmable digital inputs/outputs and analog inputs. The controller processes control signals from analog joysticks, digital signals from a gyroscope and utilizes a MUX to expand the analog input capabilities of the Arduino. The …

Dc-Dc Converter For Electric Vehicle, Jason Y. Zhou, Nicholas James Mah

Electrical Engineering

In this work, a DC-DC converter is designed for an electric vehicle. The DC-DC converter is designed to provide 500W with a 200-400V input and a 12-15V adjustable output. Electric vehicle sales are beginning to increase in popularity and the need for DC-DC converters to siphon power from the tractive system is not yet fully satisfied, especially for single-seater class vehicles. Additionally, improving performance in efficiency without sacrificing wide input voltage range can benefit future DC-DC converter designs. In the end, a forward active clamp DC-DC converter is designed and tested. Additionally, spreadsheet calculators, LTSpice simulations, and Matlab scripts were …

Human Sensing Expansion For A Rolling Robot, Eric Hanson

Electrical Engineering

For the past twenty years, fans of the Star Wars movies have been building their own replica robots or “droids” that they fell in love with on the big screen. This project takes an existing design for the BB-8 droid and integrates sensors that can detect people and then interact with them. This design uses six IR sensors and one main 8x8 IR sensor grid to be able to detect the closest person and turn BB- 8’s dome towards them as though they are looking at them.

Cmos Design Of An 8-Bit 1ms/S Successive Approximation Register Adc, Ameya Vivekanand Ganguli

Master's Theses

Rapid evolution of integrated circuit technologies has paved a way to develop smaller and energy efficient biomedical devices which has put stringent requirements on data acquisition systems. These implantable devices are compact and have a very small footprint. Once implanted these devices need to rely on non-rechargeable batteries to sustain a life span of up to 10 years. Analog-to-digital converters (ADCs) are key components in these power limited systems. Therefore, development of ADCs with medium resolution (8-10 bits) and sampling rate (1 MHz) have been of great importance.

This thesis presents an 8-bit successive approximation register (SAR) ADC incorporating an …

Designing A Simulator For An Electrically-Pumped Organic Laser Diode, Robert Hulbert

Master's Theses

Organic semiconductors provide an alternative set of basis materials to fabricate electronic devices like PN Junctions, LEDs, and FETs. These materials have several benefits over traditional inorganic semiconductors including their mechanical flexibility, reliance on renewable resources, and inexpensive large-scale manufacturability. Despite the contemporary device implementations with organic semiconductors, a solid-state electrically-pumped organic laser diode does not exist. However, organically-based lasers do exist by utilizing the organic material strictly for optical gain. The challenge occurs when charge carriers appear in the organic material. The charge carriers must reach a concentration such that population inversion occurs producing optical gain. However, between the …

Blind Separation For Intermittent Sources Via Sparse Dictionary Learning, Annan Dong

Dissertations

Radio frequency sources are observed at a fusion center via sensor measurements made over slow flat-fading channels. The number of sources may be larger than the number of sensors, but their activity is sparse and intermittent with bursty transmission patterns. To account for this, sources are modeled as hidden Markov models with known or unknown parameters. The problem of blind source estimation in the absence of channel state information is tackled via a novel algorithm, consisting of a dictionary learning (DL) stage and a per-source stochastic filtering (PSF) stage. The two stages work in tandem, with the latter operating on …

Probabilistic Spiking Neural Networks : Supervised, Unsupervised And Adversarial Trainings, Alireza Bagheri

Dissertations

Spiking Neural Networks (SNNs), or third-generation neural networks, are networks of computation units, called neurons, in which each neuron with internal analogue dynamics receives as input and produces as output spiking, that is, binary sparse, signals. In contrast, second-generation neural networks, termed as Artificial Neural Networks (ANNs), rely on simple static non-linear neurons that are known to be energy-intensive, hindering their implementations on energy-limited processors such as mobile devices. The sparse event-based characteristics of SNNs for information transmission and encoding have made them more feasible for highly energy-efficient neuromorphic computing architectures. The most existing training algorithms for SNNs are based …

Supercapacitors With Gate Electrodes, Tazima Selim Chowdhury

Dissertations

A new approach to improve the capacitance of supercapacitors (SC) is proposed in this study. A typical SC is composed of an anode and a cathode; a separator in between them assures an unintentional discharge of the capacitor. The study focuses on a family of structured separators, either electronically active or passive which are called gates. An active structured separator layer has been fabricated and analyzed. The structured separator has characteristics of electrical diode and is fabricated out of functionalized carbon nanotubes (CNT). Improvement of the overall capacitance of SC, equipped with either active or passive structured separators demonstrated a …

Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip

Dissertations

Light-emitting diodes (LEDs) using III-nitride nanowire heterostructures have been intensively studied as promising candidates for future phosphor-free solid-state lighting and full-color displays. Compared to conventional GaN-based planar LEDs, III-nitride nanowire LEDs exhibit numerous advantages including greatly reduced dislocation densities, polarization fields, and quantum-confined Stark effect due to the effective lateral stress relaxation, promising high efficiency full-color LEDs. Beside these advantages, however, several factors have been identified as the limiting factors for further enhancing the nanowire LED quantum efficiency and light output power. Some of the most probable causes have been identified as due to the lack of carrier confinement in …

Blind Source Separation Using Dictionary Learning Over Time-Varying Channels, Anushreya Ghosh

Theses

Distributed sensors observe radio frequency (RF) sources over flat-fading channels. The activity pattern is sparse and intermittent in the sense that while the number of latent sources may be larger than the number of sensors, only a few of them may be active at any particular time instant. It is further assumed that the source activity is modeled by a Hidden Markov Model. In previous work, the Blind Source Separation (BSS) problem solved for stationary channels using Dictionary Learning (DL). This thesis studies the effect of time-varying channels on the performance of DL algorithms. The performance metric is the probability …

Surface Engineering Solutions For Immersion Phase Change Cooling Of Electronics, Brendon M. Doran

Master's Theses

Micro- and nano-scale surface modifications have been a subject of great interest for enhancing the pool boiling heat transfer performance of immersion cooling systems due to their ability to augment surface area, improve wickability, and increase nucleation site density. However, many of the surface modification technologies that have been previously demonstrated show a lack of evidence concerning scalability for use at an industrial level. In this work, the pool boiling heat transfer performance of nanoporous anodic aluminum oxide (AAO) films, copper oxide (CuO) nanostructure coatings, and 1D roll-molded microfin arrays has been studied. Each of these technologies possess scalability in …

Developing An Optomechanical Approach For Characterizing Mechanical Properties Of Single Adherent Cells, Ali Mehrnezhad

LSU Doctoral Dissertations

Mechanical properties of a cell reflect its biological and pathological conditions including cellular disorders and fundamental cellular processes such as cell division and differentiation. There have been active research efforts to develop high-throughput platforms to mechanically characterize single cells. Yet, many of these research efforts are focused on suspended cells and use a flow-through configuration. Therefore, adherent cells are detached prior to the characterization, which seriously perturbs the cellular conditions. Also, methods for adherent cells are limited in their throughput.

My study is aimed to fill the technical gap in the field of single cell analysis, which is a high-throughput …

Coupled Correlates Of Attention And Consciousness, Ravi Varkki Chacko

McKelvey School of Engineering Graduate Student Theses & Dissertations

Introduction: Brain Computer Interfaces (BCIs) have been shown to restore lost motor function that occurs in stroke using electrophysiological signals. However, little evidence exists for the use of BCIs to restore non-motor stroke deficits, such as the attention deficits seen in hemineglect. Attention is a cognitive function that selects objects or ideas for further neural processing, presumably to facilitate optimal behavior. Developing BCIs for attention is different from developing motor BCIs because attention networks in the brain are more distributed and associative than motor networks. For example, hemineglect patients have reduced levels of arousal, which exacerbates their attentional deficits. More …

Quantitative Hyperspectral Imaging Pipeline To Recover Surface Images From Crism Radiance Data, Linyun He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Hyperspectral data are important for remote applications such as mineralogy, geology, agriculture and surveillance sensing. A general pipeline converting measured hyperspectral radiance to the surface reflectance image can provide planetary scientists with clean, robust and repeatable products to work on.

In this dissertation, the surface single scattering albedos (SSAs), the ratios of scattering eciency to scattering plus absorption eciences of a single particle, are selected to describe the reflectance. Moreover, the IOF, the ratio of measured spectral radiance (in the unit of watts per squared-meter and micrometer) to the solar spectral radiance (in the unit of watts per squared-meter and …

Optimal And Efficient Decision-Making For Power System Expansion Planning, Mahdi Mehrtash

LSU Doctoral Dissertations

A typical power system consists of three major sectors: generation, transmission, and distribution. Due to ever increasing electricity consumption and aging of the existing components, generation, transmission, and distribution systems and equipment must be analyzed frequently and if needed be replaced and/or expanded timely. By definition, the process of power system expansion planning aims to decide on new as well as upgrading existing system components in order to adequately satisfy the load for a foreseen future.

In this dissertation, multiple economically optimal and computationally efficient methods are proposed for expanding power generation, transmission, and distribution systems. First, a computationally efficient …

Very Low Power Cockcroft-Walton Voltage Multiplier For Rf Energy Harvesting Applications, Trace Langdon

Electrical Engineering Undergraduate Honors Theses

A device was required that could harvest the electromagnetic energy present in ambient radio frequency (RF) signals. A part of this device must convert the AC RF signal received by the antenna into a DC signal that can be used in an embedded application. Since the RF signal amplitude is small, it must first be amplified and rectified to become a usable signal. The Cockcroft-Walton voltage multiplier is a subsystem of the design which ideally converts a 100 mV AC signal coming from the antenna to a 350 mV DC signal. The output of the voltage multiplier is used to …

Design Of Two-Stage Operational Amplifier Using Indirect Feedback Frequency Compensation, Roderick Gomez

Electrical Engineering Undergraduate Honors Theses

This thesis work details the designing process of two silicon two-stage operational amplifiers with indirect feedback compensation and with Miller compensation technique. The main objective of this thesis is to study the advantages of indirect feedback compensation in comparison with Miller compensation and how this technique can be applied to meet certain design specifications. The operational amplifiers are designed with 130 nm Silicon Germanium CMOS process ideally for temperature range of 25°C to 300°C. The two op-amps are designed to have a DC gain of about 70 dB and 60 degrees of phase margin. The indirect feedback compensation design showed …

Designing, Simulating, And Layout Of An Rfic Mixer In A 130 Nm Sige Process, Logan Walz

Electrical Engineering Undergraduate Honors Theses

Wireless devices are becoming increasingly popular each day ranging from smartphones to Amazon Echo’s to wireless sensors in industry. While all of these devices are quite different in their functions and purposes, they all rely on wireless communication heavily and signal modulation techniques. One component typically seen in wireless applications like this are mixers, which are used to modulate the signal being sent and received. This thesis details the design, simulation, and layout of a radio frequency integrated circuit mixer in a 130 nanometer silicon germanium process. While the fabricated mixer did not perform to standards, many things were learned …

Characterization Of High Temperature Optocoupler For Power Electronic Systems, David Gonzalez

Electrical Engineering Undergraduate Honors Theses

High-temperature devices have been rapidly increas due to the implementation of new technologies like silicon carbide, high-temperature ceramic, and others. Functionality under elevated temperatures can reduce signal integrity reducing the reliability of power electronic systems. This study presents an ongoing research effort to develop a high-temperature package for optocouplers to operate at higher temperature compared with commercial devices. Low temperature co-fired ceramic (LTCC) was used as the substrate. Bare die commercial LED and photodetectors were attached to the substrate and tested for functionality. Preliminary results show enhanced performance at elevated temperatures compared to a commercial optocoupler device.

Modeling Solder Ball Array Interconnects For Power Module Optimization, Paul Swearingen

Electrical Engineering Undergraduate Honors Theses

PowerSynth is a software platform that can co-optimize power modules utilizing a 2D topology and wire bond interconnects. The novel 3D architectures being proposed at the University of Arkansas utilize solder ball interconnects instead of wire bonds. Therefore, they currently cannot be optimized using PowerSynth. This paper examines methods to accurately model the parasitic inductance of solder balls and ball grid arrays so they may be implemented into software for optimization. Proposed mathematical models are validated against ANSYS Electromagnetics Suite simulations. A comparison of the simulated data shows that mathematical models are well suited for implementation into optimization software platforms. …

Prototyping A Capacitive Sensing Device For Gesture Recognition, Chenglong Lin

Computer Science and Computer Engineering Undergraduate Honors Theses

Capacitive sensing is a technology that can detect proximity and touch. It can also be utilized to measure position and acceleration of gesture motions. This technology has many applications, such as replacing mechanical buttons in a gaming device interface, detecting respiration rate without direct contact with the skin, and providing gesture sensing capability for rehabilitation devices. In this thesis, an approach to prototype a capacitive gesture sensing device using the Eagle PCB design software is demonstrated. In addition, this paper tested and evaluated the resulting prototype device, validating the effectiveness of the approach.

A Method For The Measurement Of The Latency Tolerance Range Of Western Musicians, Jorge Medina Victoria

PhDs

This thesis presents a new systematic method to measure the ability of western musicians to cope with latency. The core of the method is a listening test and the development of a measure. The viability of the method is statistically tested with an empirical observation of 31 test subjects performing on 17 different musical instruments.

The primary goal of the investigation is the development of a systematic, reliable and replicable method that can be applied to different western music instruments, in order to provide data for analysis on latency issues while performing music in non-collaborative performances. In addition, a measure …

Research Of Electro-Optical Effect In Metal Halide Perovskites By Fabry-Perot Interometer Method, Hanxiang Yin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Perovskites have been investigated a lot by present and reported with outstanding optoelectronic properties. However, so far there is no publications about another important property, the electro-optical (EO) effect which is related to important applications in photolithography. This thesis is mainly mean to calculate the EO constants of one kind of organic perovskite material, CH₃NH₃PbI₃, which has been reported to have good capability of forming film by spin-coating, through the way of putting the film of CH₃NH₃PbI₃ between two layers of metal mirrors to build a Fabry-Perot interferometer and …

Ac Direct Drive Led Lighting Using Low Cost Analog Components, Miles Head

Master's Theses

This project explores the rapidly expanding area of AC direct drive for LED lighting. AC LED driving does not use typical DC-DC converter-based driving but uses semiconductor switches and a linear regulator to activate a number of LEDs proportional to the input voltage at any given time. This allows bulky, expensive magnetics to be eliminated from the system. The goal of this project was to design a scaled-down physical AC LED direct drive system to validate the conclusions of methods for improving efficiency from a previous investigation that found minimizing voltage across the linear regulating MOSFET led to higher efficiency …

Granny Pod Virtual Assistant, David Connolly, Bing Chen

Theses/Capstones/Creative Projects

Dr. Chen is working on a sustainable small house (SSH) project, sometimes called the “Granny Pod”. Regulations will soon allow homeowners to house their parents on their property, which can be an opportunity live independently in a cheap, sustainable, and convenient alternative to a retirement community. To help achieve this vision, a Virtual Assistant system for the SSH was developed. The system uses a Google Home or Amazon Echo to respond to the voice command “Hey Google (or Alexa), I need help” by contacting the nearby homeowner or caretaker. It alerts the resident who is at the door when the …