Engineering Commons^™

Wirelessly Controlled Smart Outlet, Andrew Godsil, Ariel Dubinsky

Electrical Engineering

Popularity of home automation devices has increased greatly in recent years due to higher affordability and simplicity through smartphone and tablet connectivity. For the purpose of this experiment, we have developed the Smart Outlet: a stand-alone communication unit, used to connect home outlets to the internet. The Smart Outlet controls lighting and simple appliances throughout the home, remotely, using wireless commands from the web. A Google Calendar interface directly controls the outlets’ function by scheduling them with dedicated calendar events. The calendar’s interface can even be accessed from multiple different platforms (i.e. phones, computers, tablets) for the convenience of all …

High Voltage Pulse-Width Generator For The Algae Biofuel Project, Philip Yu, Stephen Leung

Electrical Engineering

This purpose of this project, sponsored by Boeing and advised by Dr. Arakaki and Dr. Taufik, is to build a high voltage pulse width generator that lyses algae cells to harvest the biofuel within. This project uses Emmanuel Loza's thesis on a cascaded high voltage converter with variable control to build a portable pulse width generator with independent control on the peak voltage, pulse width, and frequency. The project focuses on creating a pulse width generator capable of finding the most optimal pulsed electric field to lyse algae. The pulse width module ranges from 10V-80V peak voltage, 60Hz-100 kHz frequency, …

Energy Harvesting From Exercise Machines: Lt8705 Dc-Dc Conversion For Elliptical Trainers, Braden Burk, Raj Bhula, Nathan Mckay

Electrical Engineering

Cal Poly’s Energy Harvesting from Exercise Machines (EHFEM) program aims to power the grid using human energy harvested from exercise machines in its gym. Doing so could save the school money and increase the total supply of power available on the grid. This document belongs to one of many groups attempting to design a suitable DC-DC conversion system for an elliptical trainer using an LT8705 Four-Switch Buck-Boost converter. Past teams have built other converters and developed system compatibility characteristics such as filtering, safety, and stability for interfacing components. These teams fall into one of two departments in EHFEM: DC-DC Conversion …

Microprocessor Management Of Energy Harvesting Buck Boost Converters, Timothy O'Sullivan

Electrical Engineering

No abstract provided.

Power Chest Strap, Adrianne Thoroddsson, Dennis Lin

Electrical Engineering

The Power Chest Strap is an unobtrusive device, like a heart rate monitor, worn around the chest that harvests energy from the expansion of the chest during breathing. The chest strap stores electrical energy that can charge electronic devices such as cell phones. Since small portable devices grow in number, the power strap allows a convenient way to charge your device without having to find a wall outlet for a charger. Research on systems that scavenge energy from arm or leg movement already exist, but these systems require the ability of the user to move their arms and legs. The …

Buck Converter, Bowen Liu

Electrical Engineering

The recent sustainable energy growth triggered a huge power electronics demand, specifically related to power conversion. My senior project is a design of a buck converter which steps down the voltage from photovoltaic cells ranging from 5 to 40V to a rechargeable battery with 5V. This converter has a high enough power efficiency to effectively convert the energy harnessed from PV panels.

A Prototype Microwave Cavity Control Circuit For Use In Next Generation Free Electron Laser, Josh Thompson, Peter Neal Barrina, Jiayi Jiang, Joe Frisch, Steve Smith, Daniel Van Winkle

STAR Program Research Presentations

One of the current programs at SLAC National Accelerator Laboratory is the Linac Coherent Light Source, or LCLS. Using the existing hardware of the last third of their linear accelerator (or “linac”), SLAC has created one of the most energetic X-ray free electron lasers (or “FEL”). Since 2009, LCLS has used this FEL to perform a wide range of experiments across all sciences, most notably ultrafast filming at the molecular scale. As requests for beam-time with this laser increases, SLAC is purposing a linac upgrade to better match this demand. This upgrade, named LCLS-II, will replace existing copper radio frequency …

Grid-Scale Energy Storage: A Proposed Control Algorithm For Sodium Sulfur Batteries, Daniel Spaizman

Master's Theses

With carbon dioxide levels in our atmosphere reaching record highs and 2020 quickly approaching, California is expected to pave the way for the United States in terms of replacing fossil fuel generation facilities with various renewable energy power plants. It is well documented that the inherent variability and limited duty cycle of renewables has hindered their growth. Energy storage technologies represent the bridge that can help us cross the divide from where we stand to where we must stand in the next 6 years. Utility companies value services such as peak shaving, voltage support, and frequency regulation, all of which …

Cnc Torch, Steven Chiu

Computer Engineering

This CNC Torch cuts steel plate. It can cut up to a maximum area of 3x3 feet. The user builds a cut list on the touchscreen from a selection of predefined shapes and enters the parameters need for each shape. When the user is ready, the cut list is sent to an Arduino that will move each motors accordingly to the shapes desired.

Merry-Go-Round Human Powered Generator, Sarah Lorraine Ashe, Salvador Navarro

Electrical Engineering

How do you bring electricity to families who have limited resources in a developing country? The DC House project, advised by Dr. Taufik, provides a way for kids to have fun, exercise and generate power for their homes – play-park human powered generators. This project intends to create a more efficient and cost effective way for playground equipment to be implemented for power generation. The redesigned and reconstructed merry-go-round human powered generator converts mechanical energy into electrical energy to power the DC house. This was a fully functioning generator that needed a better voltage gain, as well as, a more …

Human-Powered Swing Generator, Danny Cai, Timothy Lai, Brandon Wong

Electrical Engineering

Many developing countries lack sufficient resources to provide enough electricity for every family to live with a satisfying level of comfort and convenience. Our project proposes a solution that provides families with an alternative access to electricity using a playground swing. This project addresses the design and construction of the Human-Powered Swing Generator, which converts mechanical energy to electrical energy for charging a battery. The charged battery serves as a source of DC energy for potential DC purposes, such as charging a cell phone.

Piezoelectric Powered Led Street Reflector, Collin Shane Douglass

Electrical Engineering

In many areas of Washington, it rains for a majority of the year. During rainy weather it becomes difficult to see street lanes and dividers, causing hazardous road conditions. The Piezoelectric Powered LED Street Reflector solves this problem. The PPL Street Reflector modifies a street reflector with LED lights. These lights help drivers clearly see where dividers and street lines are in non-ideal weather conditions, such as rain, fog, and snow. The PPL Street Reflector capabilities include harvesting energy through the Piezoelectric Effect, creating a self-sustaining device with minimal maintenance.

Design Improvement For The Smart Dc Wall Plug, Cory Yee, Haoyan Huang

Electrical Engineering

The DC smart wall plug is a subsystem within the Cal Poly DC House Project. The previous version faces challenges supplying DC voltage to meet household appliances’ nominal values. Specifically, it can only output the minimum required voltage for DC appliances to operate, resulting in unwanted power loss. In addition, the maximum output voltage is rated at 15V, which is insufficient to power most DC appliances. This design improvement project incorporates NFC technology as a solution to overcome the power loss and a new buck converter configuration to increase the output voltage range. Additionally, the new design introduces short-circuit and …

Energy Harvesting From Exercise Machines - Dc-Dc Buck Boost Converter (Lt3791), Matthew B. Wong

Electrical Engineering

Cal Poly’s ongoing Energy Harvesting From Exercise Machines (EHFEM) project proposes sustainability and energy saving costs through modifying exercise machines generating DC power, providing a renewable energy resource through physical exercise. The EHFEM project contains multiple sub-projects involving modifying several different exercise machines. Each machine generates DC power and an inverter converts this power to AC. This AC power returns to the grid. This project addresses an issue involving a previously installed DC-DC converter not returning power properly. When generating DC power, the grid demands a specific AC voltage, but the generated power through the previous DC-DC converter and power …

All Purpose Mobile Gps, James C. Smith, Matt Weege, Kevin Peters

Electrical Engineering

The aim of the All Purpose Mobile GPS (The System) is to create a GPS tracking device that can accurately record location and calculate velocity, distance traveled and elevation change even when the satellite signal is lost. This data can later overlay on existing internet-based maps illustrating a trip to oneself or others. The portable tracker consumes very little power achieving several days’ worth of power in a single charge. A solar cell provides a quick battery boost in a pinch. SD Card storage increases compatibility with computers and other forms of data transfer. Data processing, such as viewing the …

Battery Management System, Michael Desando, Kyle Woody

Electrical Engineering

Problem Statement:

There have been recent reports of multi-million dollar companies having to recall entire projects due to their BMS’s malfunctioning or operating incorrectly. The purpose of this project is to analyze the future of batteries, the Lithium-Ion cell, and to exercise a BMS to better understand its capabilities and possible cases for errors. Lithium ion batteries are intolerant of overcharge and overdischarge. Abuse of this kind can result in high temperatures, venting of gases, fire, or explosion. Therefore battery management systems have been devised to prevent such abuse. Recent events such as fires on the Boeing Dreamliner and the …

Portable Nano Hydro Generator For The Dc House Project, Caleb David Fink, Victor Olusoji Ojewole, Christopher Mapua Tan

Electrical Engineering

This Senior Project entails the design and testing processes of the Portable Nano Hydro Generator for the continuing DC House Project. No natural resources should go unused, especially in developing countries where they are found in abundance. Small streams in particular have potential to further Professor Taufik's DC House Project that will provide electricity to 1.6 billion people in the world without access to electricity upon completion. The goal of this project is to create a small portable generator that utilizes the discharge from small streams and convert it into useable electricity that could charge a car battery as an …

Wind And Ventilation Turbine (Wvt) Generator, Anthony Lloyd, Jacob Michener

Electrical Engineering

This project aims to create a more compact and accessible renewable energy source using the Wind and Ventilation Turbine (WVT) Generator. The wind turbine provides ventilation while generating “clean” electricity using solar and kinetic energy. The electrical generation causes no functional losses to the ventilation as rising heat and passing wind turn the turbine, ventilating the house. Placing a generator beneath the spinning turbine allows for the transformation of mechanical motion into electrical energy. The system charges a battery, supplying recharging power into small standard electronics (i.e. cell phones, tablets, etc.) through a USB output.

Integration Of Pv & Simulated Dc Sources For The Dc House, Arvind Ramesh, Kevin Gingrich, Scott Chau

Electrical Engineering

The DC House, an ever improving project, uses only pure DC power which most renewable energy sources generate, from solar to wind power. The DC House and this project expect a donation of photovoltaic modules to supply a constant source of DC power. At the moment, the DC House desperately needs power sources because not only does the house have various loads unaccounted for, but the distribution system to determine proper power flow needs a redesign. The project chose to account for these issues by implementing a solar panel onto the DC House and a power distribution module to have …

Buck-Boost Dc-Dc Converter With Input Protection System For The Energy Harvesting From Exercise Machines Project, Byungjae David Yoo, Sheldon Tyler Kong Ming Chu

Electrical Engineering

Cal Poly’s Energy Harvesting from Exercise Machines (EHFEM) project comprises of multiple subprojects seeking to effectively create a sustainable energy source through harvesting electrical energy generated from physical exercise machines. This project designs and implements a Buck-Boost DC-DC converter using a LT3791-1 4-Switch Buck-Boost Controller, replacing the previous SEPIC design. The DC-DC converter must operate within limits set by the maximum input range of the LT3791-1 controller. An input protection system prevents inputs higher than rated values, which may adversely damage the Buck-Boost DC-DC converter. These inputs include overvoltage transients, average voltage, and current output by the Precor EFX 561i …

Dual High-Voltage Power Supply For Use On Board A Cubesat, Nicholas Weiser

Master's Theses

Since their conception in 1999, CubeSats have come and gone a long way. The first few that went into space were more of a “proof of concept,” and were more focused on sending simple data and photographs back to Earth. Since then, vast improvements have been made by over 40 universities and private firms, and now CubeSats are beginning to look towards interplanetary travel. These small satellites could provide a cost effective means of exploring the galaxy, using off the shelf components and piggy-backing on other launch vehicles with more expensive payloads. However, CubeSats are traditionally launched into Low Earth …

Smart Wall Outlet Design And Implementation For The Dc House Project, Kevin Roy Mendoza

Master's Theses

Most everyday AC appliances are designed to operate off of 120V coming from the wall outlet in our homes. This voltage is a standard set from our established infrastructure. Unlike AC devices, DC devices do not have any set standard of voltage they all will run off of. This presents a problem for the DC house as the various loads that will be used will have different required input voltages. One set voltage for a wall outlet will not suffice for the DC House. This Smart Wall Outlet is designed with a DC-DC converter that will have its output voltage …

Improvements To A Bi-Directional Flyback Dc-Dc Converter For Battery System Of The Dc House Project, Michael Wu

Master's Theses

The DC House project relies primarily on renewable energy sources to provide DC power to the various loads of the house. However, not all renewable sources are capable of providing power at all times of the day. A back-up energy source in the form of a battery storage system must be available to meet the electrical needs of the house. A bi-directional flyback power converter was initially designed to allow a battery to charge from as well as discharge to the 48V bus line of the DC House. The design provided a 35W prototype to demonstrate the converter’s feasibility. Further …

Modeling And Simulation Of Parallel D-Statcoms With Full-Wave Rectifiers, Jason Brinsfield

Master's Theses

In recent years, both a significant increase in electrical demand and a large influx of intermittent renewable energy sources have put a considerable stress on the nation’s electrical grid. Conventional power flow control techniques such as capacitor banks and tap-changing transformers are incapable of adequately handling the rapid fluctuations in power supply and demand that today’s grid experiences. Flexible AC Transmission System (FACTS) controllers are a practical way to compensate for such rapid power fluctuations. One type of shunt FACTS controller is the Static Synchronous Compensator (STATCOM), which uses fully controllable switches to source or sink reactive power to a …

Boosty-Bit: Power For Pint-Sized Projects, Timothy Grijalva

Electrical Engineering

In order to make it easier for hobbyists to create small portable microcontroller based electronics projects, I have created Boosty-bit, a tiny DC-DC boost convert that runs off a single alkaline battery cell (AA or AAA). The Boosty-bit converter can source up to 250mA @ 3.3v, making it ideal for many microcontroller based projects. In addition to power management, Boosty-bit is also physically small, allowing it to fit inside pen/marker-sized enclosures along with a AAA battery and a microcontroller. Boosty-bit aims to be the ideal solution for “makers” who desire portability and compact form factors in their projects.