Electrical and Electronics Commons^™

Complex Filters As As A Cascade Of Of Buffered Gingell Structures: Design From From Band-Stop Constraints, Samuel Robert Johnston

Master's Theses

This thesis presents an active Complex Filter implementation that that creates a transfer function with with a single real pole and a complex zero. The two-input/two-output network developed in in this thesis responds differently based upon upon the relative phase difference of of the two inputs. If a negative ninety-degree phase difference occurs between the two inputs, the filter will exhibits a bandstop response. While a positive ninety-degree phase difference exhibits a bandpass response. This topology is relatesd to to Gingell’s RC-CR polyphase topology but because of of the use of of op-amps, can be cascadedd without without suffering loading …

Manufacturing And Characterization Of Poly (Lactic Acid)/Carbon Black Conductive Composites For Fdm Feedstock: An Exploratory Study, Dylan Fitz-Gerald, Justin Boothe

Materials Engineering

This exploratory study developed methods of manufacturing and characterizing the electrical properties of small batches of conductive composite feedstock for the Fused Deposition Modeling (FDM) manufacturing process, commonly known as 3D printing. We utilized a solution casting process of Poly(lactic acid) (PLA) (Grade 4043D, NatureWorks, LLC.) and Carbon Black (CB) (Vulcan® XC72, Cabot Corp.) in chloroform. The resulting composite precursor was cryogenically treated with liquid nitrogen and milled in a coffee grinder in order to achieve particles that could be fed into the extruder. Composite precursors were dried in a vacuum oven at an elevated temperature of 38°C. Filaments were …

Testing Feasibility Of Inductive Power Coupling For Modern Applications, Andrew Burman

BioResource and Agricultural Engineering

This project takes two bifilar tesla coils and uses them to find a % efficiency of power transfer as distances between the coils decrease. The reason this experiment is being conducted is to find possible implications for wireless charging of vehicles using similar style coils. This project conducted experiments on 60 Hz, 400 Hz, and 1 kHz frequencies for a small input signal. The general conclusion is that as the frequency increases more power can be transferred and higher efficiency of power transfer is seen. This project also concluded that it could be possible to get higher efficiency at a …

Design And Implementation Of A Three Dimensional Printer Using A Cylindrical Printing Process, Brandon Hoy

Electrical Engineering

Many 3D printers utilize a Cartesian (XYZ) printing process. Implementing a polar coordinate printer providing a faster printing method and introduces new printing algorithms, increasing printing efficiency. This cylindrical 3D printer applies a circular-moving baseplate and a heating printer head (extruder) moving radially and vertically. A processor accepts pre-processed polar data points and transpose the appropriate programmed printing commands to the motors units. The extruder also has a control loop, keeping the temperature inside the desired range. This prototype prints using polylactic acid (PLA) filament. Additionally, a display screen updates every second the: printing time, extruder temperature, and status notifications.

Rapid Battery Exchange (Rbx), Daniel Rostom

Electrical Engineering

Electric vehicles have begun to hit the main stream market, with sales raising form under 20,000 in 2001 to over 110,000 per year since 2014 [1]. With new models hitting the market every year, and more people becoming conscious about their fossil fuel usage, this trend will only continue until there are more electric vehicles than combustion vehicles on the road. A major drawback of electric vehicles is their limited range, and relatively long recharge times. Even with advancements in battery charging speed, such as the Tesla super charger, able to provide up to 90 miles of range in just …

Active Charge Balancing For Cardiac Stimulation, Maci Miri

Electrical Engineering

Worldwide, there are about 3 million people who have pacemakers, with 10,000 new implantations of ICD’s each month. [heart.org] Due to the gravity and importance of the function that ICD’s provide, these devices must be extremely reliable and highly effective. However, because of the high tolerances of IC manufacturing, stimulation circuits for pacemakers may be slightly unmatched and over time, may have a net DC charge applied to the tissues in the heart. Extra charge pumped into body tissues is dangerous for the patient’s health; the pH of the tissue can be raised and corrosion of the stimulating electrodes may …

A Stroke Therapy Brace Design, Evan Kirkbride

Electrical Engineering

Victims of stroke often have difficulty with rehabilitation. With limited movement on their affected arm, patients often do not want to move much for physical therapy. In this project, we design a robotic brace that helps stroke patients move their arm more effectively in a reaching or pulling motion. By giving patients more movement in their affected arm than they would have otherwise, patients gain more from rehabilitation. The brace also adapts to the patient’s needs, providing more inclination or resistance as needed for their physical therapy. This kind of therapy engages patients rather than relying on their likely dwindled …

Car Safe, David Van Workum

Electrical Engineering

The Car Safe project helps protect parents and caretakers from the dangers associated with leaving children in hot vehicles. The device supports parents through notifying them of the child’s wellbeing and status while within an automobile. Specifically, the device monitors the child’s ergonomic experience and the spatial proximity between the caretaker and child. Car Safe utilizes this information and determines if the child finds himself in a dangerous environment. Due to its compact design, the device functions independently of a specific car seat design, allowing customers to integrate Car Safe in the car seat environment of their choosing.

Design Of An Integrated Acceleration Acquisition Subsystem To Satisfy High-Speed And Low-Area Requirements For Cubesats, Ryan J. Rumsey

Master's Theses

Cal Poly San Luis Obispo’s PolySat team is designing the Multipurpose Orbital Spring Ejection System (MOSES) in order to record acceleration data during the launch of CubeSats as well as to provide GPS coordinates to locate the position of CubeSats once they are injected into orbit. This work focuses on the design and development of the acceleration data acquisition (DAQ) subsystem of MOSES. This subsystem is designed around the need for a high-speed sampling system of at least 200 kHz across four channels of data, plus low-area limitations in the MOSES form factor which is roughly half the size of …

Hall Effect Modeling In Fem Simulators And Comparison To Experimental Results In Silicon And Printed Sensors, Leonardo A. Frem

Master's Theses

Finite element method simulation models for thin-film semiconductor-based Hall sensors were developed using secondary data in order to understand their behavior under strong magnetic fields. Given a device geometry and charge carrier density and mobility, the models accurately calculated sensor resistance, Hall voltage under a normally-incident constant magnetic field, and expected offset from a population of Hall devices. The model was successfully matched against data from integrated chip Hall sensors from St. Jude Medical. Additionally, the feasibility of creating Hall effect devices with common carbon ink was explored experimentally. The material properties obtained from testing these ink-based devices through the …

Low-Frequency Series Loaded Resonant Inverter Characterization, Alfredo Medina

Master's Theses

Modern power systems require multiple conversions between DC and AC to deliver power from renewable energy sources. Recent growth in DC loads result in increased system costs and reduced efficiency, due to redundant conversions. Advances in DC microgrid systems demonstrate superior performance by reducing conversion stages. The literature reveals practical DC microgrid systems composed of wind and solar power to replace existing fossil fuel technologies for residential consumers. Although higher efficiencies are achieved, some household appliances require AC power; thus, the need for highly efficient DC to AC converters is imperative in establishing DC microgrid systems. Resonant inverter topologies exhibit …

Usb-Powered Turntable "Turn T", Gerardo Sevilla, James Lougaris

Electrical Engineering

No abstract provided.

Ism S-Band Cubesat Radio Designed For The Polysat System Board, Craig Lee Francis

Master's Theses

Cal Poly’s PolySat CubeSat satellites have begun to conduct more complex and scientifically significant experiments. The large data products generated by these missions demonstrate the necessity for higher data rate communication than currently provided by the PolySat UHF radio. This thesis leverages the proliferation of consumer wireless monolithic transceivers to develop a 250kbps to 2000kbps, 2W CubeSat radio operating within the 2.45GHz Industrial, Scientific, and Medical (ISM) radio band.

Estimating a link budget for a realistic CubeSat leads to the conclusion that this system will require a large deployable CubeSat antenna, large earth station satellite dish, and a fine-pointing attitude …

Oceanographic Instrument Simulator, Amy Chen

Master's Theses

The Monterey Bay Aquarium Research Institute (MBARI) established the Free Ocean Carbon Enrichment (FOCE) experiment to study the long-term effects of decreased ocean pH levels by developing in-situ platforms [1]. Deep FOCE (dpFOCE) was the first platform, which was deployed in 950 meters of water in Monterey Bay. After the conclusion of dpFOCE, MBARI developed an open source shallow water FOCE (swFOCE) platform located at around 250 meter of water to facilitate worldwide shallow water experiments on FOCE [1][2]. A shallow water platform can be more ubiquitous than a deep-water platform as shallow water instruments are less expensive (as it …

Out-Of-Loop Compensation Method For Op-Amps Driving Heavy Capacitive Loads, Shubham Gandhi

Master's Theses

It is well known that real op-amps do not share most of the desirable characteristics of an ideal one, particularly those of gain and output impedance. When presented with a capacitive load, such as a MOSFET or ADC, feedback in an op-amp circuit can quickly become unstable. This thesis studies and characterizes an op-amp’s output impedance and how its interaction with this type of load creates a parasitic pole which leads to instability. Applying ideas from feedback control theory, a model for studying the problem is developed from which a generalized method for compensating the undesirable circumstance is formulated.

Even …

Wide-Band Gap Devices For Dc Breaker Applications, Olukayode O. Sodipe

Master's Theses

With the increasing interest in wide-band gap devices, their potential benefits in power applications have been studied and explored with numerous studies conducted for both SiC and GaN devices. This thesis investigates the use of wide-band gap devices as the switching element in a semiconductor DC breaker. It involves the design of an efficient semiconductor DC breaker, its simulation in SPICE, construction of a hardware prototype and the comparative study of SiC and Si versions of the aforementioned breaker. The results obtained from the experiments conducted in the process of concluding this thesis show that the SiC version of the …

Mohat Tool To Illustrate Diode And Transistor Modes Of Operation Using Ltspice, Getu D. Engdaw

Electrical Engineering

This project develops a tool to identify the modes of operation of diodes and transistors in a circuit. The MoHAT tool receives schematics or circuit files generated from LTspice, and it determines the state of each diode and transistor. This tool illustrates diodes, BJT and MOS regions of operations using text or graphics accordingly. The tool also suggests necessary adjustments to switch from one mode of operation to another upon users request. Furthermore, the tool specifies if a transistor functions in amplification region. The MoHAT tool compares the nodal voltages of an element and determines the mode of operation.

Midfield Rf Signal Detector, Dawei Zhang

Electrical Engineering

This project is part of a Master’s thesis which looks at alternative ways to measure blood glucose. The Master’s thesis uses mid-field signals in order to match impedance and therefore lose less power as they travel through flesh. The goal of this senior project is to build a receiver for those signals and give accurate RSSI (received signal strength indicator) measurements. Mid-fields were originally explored by Stanford professor Dr. Ada Poon [3] who used the signaling technique to recharge the batteries of deeply implanted devices. Devices implanted near the surface of the skin were able to have their batteries recharged …

Scaled Synthetic Aperture Radar System Development, Ryan K. Green

Master's Theses

Synthetic Aperture Radar (SAR) systems generate two dimensional images of a target area using RF energy as opposed to light waves used by cameras. When cloud cover or other optical obstructions prevent camera imaging over a target area, SAR can be substituted to generate high resolution images. Linear frequency modulated signals are transmitted and received while a moving imaging platform traverses a target area to develop high resolution images through modern digital signal processing (DSP) techniques. The motivation for this joint thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Objectives include …

Rfid Microscope Lab, Patricia Carranza

Computer Engineering

The RFID Microscope Lab is a new exhibit created for the San Luis Obispo Children's Museum. The goal of the project is to create a modern, interactive exhibit that will teach children about different natural specimens through the use of technology. A computer, custom software, and RFID technology, will be used to display facts, microscopic images, and short videos of ten different specimens.

Enterprise Smart Outlet, David Faltmier, Matthew Mcgill, Luke Stencel

Electrical Engineering

The purpose of our senior project, Enterprise Smart Outlet, is to create an electrical outlet which will allow enterprise users to monitor and change their power consumption habits on a large scale. The initial goal of this project is to allow consumers to see their power consumption per outlet in real time, and then using that information conform their future habits to help them conserve electrical energy, and more importantly, money. Three requirements for our project to meet our initial goal are, the outlet will work in a standard electrical outlet and be completely compatible with current electrical standards, the …

Shark Alert: Early Warning System, Cory Peterson, Marc Rauschnot, Taylor Mcclain

Electrical Engineering

The Shark Alert Early Warning System is a device geared toward avid beach goers such as surfers, divers, and swimmers. The system is composed of an ultrasonic transmitter mounted on a shark’s dorsal fin and a receiver worn by the user around the ankle. The receiver alerts the user to the presence of a shark upon ultrasonic signal detection.

The receiver warns the user through both visual and tactile (vibration) alerts to ensure user notification. This circuit was built and tested in the EE labs and Recreation Center pools to determine transmission range. The receiver detects the transmitted signal up …

U-Larm Bike Lock Accessory, Craig Cary

Electrical Engineering

Over the past few years, anti-pollution organizations and activists have encouraged society to use eco-friendly transportation like ride-sharing and biking. According to the San Luis Obispo Police Department, however, bike owners report approximately 269 bike thefts per year. This statistic illustrates the need for a more effective way to protect bicycle property.

The development of an alarm system for the U-Lock bike lock encourages bike owners to ride their bicycles by providing them with additional measures to protect their bicycle property. This U-Lock accessory, when cut, sounds an alarm to alert nearby persons of the theft-in-progress. In order to turn …

Smart Shot: Electronic Target With Smartphone Application, Tyler Stuart Pickett, Taylor Jacob Hutchinson

Electrical Engineering

The objective of this project is to develop an electronic system for recreational shooters that functions as a target with real-time feedback. The system provides a user-friendly alternative to paper targets and expensive competition scoring systems. One of the largest challenges presented by this project is balancing cost, durability, and sensitivity. The scope of this project includes the design and implementation of a target assembly, an electronic system, and a smartphone application.

The system is comprised of three main modules: the target, the control module, and the smartphone app. The electronic target communicates wirelessly with the smartphone via Bluetooth. Once …

Rocket Cam: Low Frequency Analog Transmission Of Digital Video, Thomas J. Higdon

Electrical Engineering

The camera module provides data for improving models of dynamic events on Orbital ATK Corp. rockets and aids in troubleshooting, if necessary. Video images provide a valuable addition to the strain, vibration, shock, and acoustic data used for modeling dynamic events, such as stage separations. The cameras can record a duration of video data suitable for capturing a dynamic event and of high enough quality to aid in its modeling. The module readily integrates into the rocket’s current analog data collection systems. The project has further relevance to any other application that necessitates video data transmission over similar limited-bandwidth, analog …

Current Protection For The Energy Harvesting From Exercise Machines (Ehfem) Project, Colton Crivelli

Electrical Engineering

The Energy Harvesting from Exercise Machines (EHFEM) project intends to create an exercise machine that recycles the energy expended by an athlete operating the machine by sending it to the electric grid. The work done by the user goes through a DC-DC converter and an inverter in order to prepare it for delivery to the grid. A protection circuit ensures that the inverter does not try to pull too much current from the DC-DC converter. The project implements a current protection system that ensures the system doesn’t experience an overcurrent condition.

The Dc House Project: Electrical System Design & Construction, John Bradley

Electrical Engineering

This project entails the design and assembly of the photovoltaic system, switchboard panel enclosure, and battery enclosure for the DC House’s main electrical system. The intended purpose of this project is to provide the electrical framework necessary for future students to easily modify and add to this rendition of the DC House. The principle design implements a variety of renewable energy sources, however this senior project only uses solar power in order to maintain a manageable scope. Each of these renewable energy sources are stepped down to a voltage of 24V and input to a Multi Input Single Output DC …

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 …

Fluid Midi Ribbon Guitar, Noah Baker

Electrical Engineering

This project was developed to create a new electronic instrument based off of a guitar. The design will give the user more chord combinations than are available on a typical guitar, the ability to retune each “string”, and customizable MIDI controller outputs, while trying to retain a similar playing style. The initial design for this project included implementing an onboard synthesizer (analog or digital). This idea was scrapped for time and cost considerations and replaced with MIDI output which will yield user customizable sound through virtual instruments, such as Massive.

Forest Sign Maker, Victor Espinosa Iii, Kevin Ly, Lisa Yip

Mechanical Engineering

Executive Summary:

The Inyo National Forest is arguably one of the most beautiful locations in California, containing natural masterpieces such as Mount Whitney and the Ancient Bristlecone Pine Forest. Despite its magnificence, the Inyo National Forest can be a treacherous region. The Friends of the Inyo take pride in being able to facilitate the viewing experience for all outdoorsmen by maintaining the mountain trails, which includes providing adequate trail signage.

Unfortunately, there is a fundamental issue with the recent state of trail signage in the Inyo National Forest: the rate at which signs are being vandalized or naturally destroyed is …