Engineering Commons^™

Dc-To-Dc Buck Converter, Kyle Christopher Roman

Electrical Engineering

The growth of sustainable energy requires many components to work in harmony creating one efficient and effective system. Sustainable energy generation that produces a DC current varying in voltage requires a subsystem to convert voltage to a practical and usable value. The DC to DC Buck converter converts high DC solar generated voltage to a 12V output. This Modular -Level power electronic (MLPE) device performs as a solar charge controller for small lithium ion batteries. Fluctuating voltage levels generated by Photovoltaic cells makes the solar controller a critical part of the solar system. Regulating the DC voltage allows safe and …

Dual Method Headphone Amplifier, Joseph S. Gross, Timothy P. Murphy

Electrical Engineering

Many high impedance headphones underperform their full potential when directly connected to the audio source. Amplifiers boost the audio signal and provide the headphones with sufficient power to ensure their maximum performance. The invention of transistors caused vacuum tube implementation to decline, leaving many audiophiles unsatisfied with the transistor’s sound signature. Vacuum tubes and transistors both amplify signals, however the distinct “tube sound” has vanished.

We have designed and created a product where the user selectively switches between solid-state transistor and tube amplification to compare the sound signatures of each amplification method. The ability to switch between the solid-state and …

Flexible Custom Electric Skateboard, Caleb Adam Kelsay

Electrical Engineering

At Cal Poly traveling long distances only accessible by foot such as across campus or from the car park to class can be tiring and time-consuming. While not physically demanding, the trek consumes time in our tight college life schedule. To improve our time efficiency this project provides a relatively lightweight, powered solution to quickly and effectively travel long distances while maintaining full control and safety even on hills, a current limitation of traditional skateboards.

This electric skateboard includes the battery capacity to travel all around campus on a single charge with a compact and flexible skateboard design that provides …

Smart Dc/Dc Wall Plug Design For The Dc House Project, Richard Sinclair Liu

Master's Theses

The present day duplex wall receptacle in the United States provides 120Vrms AC at 60Hz, which comes from a standard set for AC loads by the National Electrical Manufacturers Association. With a DC system, such as what is used in the DC House project currently being developed at Cal Poly, providing DC power to DC loads presents a technical challenge due to the different required DC operating voltages of the loads. This thesis entails the design and construction of a Smart DC/DC Wall Plug, which can automatically adjust its output voltage to match any required DC load voltages. In the …

Solar Powered Single-Axis Heliostat Active Solar Tracking Device, Mason Kyle Roberts

Physics

As a means of cooking food, the burning of biomass accounts for over 4 million premature deaths in third world countries (“Household Air Pollution and Health”). The focus of this project was to explore an alternative that could utilize focused sunlight to cook food. A solar tracker was designed to be affixed to a parabolic, reflective, tilted single axis heliostat to follow the sun throughout the day and focus the reflected light to the bottom of a cooking surface. This surface became hot enough to for the preparation of food or boiling/sterilization of water.

A goal for each project was …

Blend It Wine Blending Distribution System, Connor Clarry, Russell Temple, Matt Moren

Mechanical Engineering

No abstract provided.

Inkjet Printing Of Nano-Silver Conductive Ink On Pet Substrate, Skyler Jiang

Materials Engineering

Printing of conductive ink traditionally uses copper-based ink and was used on high temperature metal substrates due to the high curing and sintering temperature of copper. In this experiment, however, Metalon JS-B25P nano-silver conductive ink was printed using an Epson Stylus C88+ inkjet printer on polyethylene terephthalate (PET) based Novele printing media made for low temperature applications. With silver’s lower sintering temperature, the nano-silver particles in this ink are desired to be able to sinter at a low enough temperature to be used on the PET substrate. The printed ink traces were cured with a temperature-controlled hotplate at 100℃, 120℃, …

Screen Printing Silver Stretchable Conductive Paste To High Density Synthetic Fabric, Allison Rose Tuuri, Wesley Graham Powell

Materials Engineering

This project investigated the viability of screen printing stretchable silver conductive paste directly onto fabric and how the resistance changed under cyclic mechanical loading. The paste tested was DuPont™ PE873 stretchable silver conductive paste, which forms a stretchable conductive path by suspending silver flakes in elastomer that can be elastically strained along with the underlying substrate. The silver pastes were printed directly onto two different high-density synthetic fabrics of different weaves. Other samples were prepared by first printing a base layer between the silver paste and the fabric. One base layer was a solvent-based dielectric (DuPont™ ME776) and a stretchable …

Logic Tiles, Andrew Wheeler, Tristan Lennertz

Computer Engineering

This project was originally conceived by Professor Andrew Danowitz as he considered the restructuring of the introductory digital design course at Cal Poly. As it stands now, students apply their knowledge of boolean algebra and combinatorial logic through the programming of a Field Programmable Gate Array (FPGA) using a Hardware Descriptive Language (HDL). While this is the industry standard for designing large, complex digital circuits, and is an fundamental skill to learn, there is a lack of actual circuit building in the process that can cause a disconnect from theory to application for students who have little-to-no experience with digital …

The Following Robot, Juan D. Cerda, Matthew S. Kwan, Vi M. Le

Computer Engineering

The objective of this project is to design, build, and test an autonomous robot with an associated Android application. The robot uses on board inertial measurement sensors (magnetometer, accelerometer, gyroscope) and coordinates itself through Bluetooth communication with the similar built­in measurement sensors on the Android phone to mimic and follow movement. The Following Robot incorporates the same basic movement functionality as a typical RC car. The robot follows the user’s phone through an application on one’s phone. This application accesses the phone’s accelerometer and gyroscope data and translates into appropriate conversions. Methods of tracking and calculating distance or angular displacement …

Hybrid Water Pump, Dylan W. Grant, Wei Chen Yeh

Electrical Engineering

This project seeks to use multiple sources to power a water pump. We will design a system which will combine inputs from solar and wind energy production to ensure the pump will have enough power to run. This will create a system powered by clean energy and will be self-sustained once completed. This will theoretically create a more sustainable source of power for the pump than only one of the sources. Because the power sources don’t require outside inputs (aside from sun and wind), the pump can be placed in a remote area. This could be very helpful in developing …

Wireless Window Blinds, Cooper Laone, Niraj Morar, Zachary Malig, Jake Phillips

Electrical Engineering

The Internet of Things asserts that there exists a global need for all objects to connect easily and accessibly. Today, smartphones, tablets, laptops and smart watches makeup just a few of the interconnected devices by the greater population. As a result a growing need for wireless connection between personal devices like phones, and computers to everyday appliances exists. This idea extends directly to households, businesses and buildings, where a growing need for smart home or smart-business appliances has taken root. Many companies like Nest, ADT and Apple make products for automated home security and in home media control. The Wireless …

Adaptive Light Dimmer, Jonathan Sato, William Xiong

Electrical Engineering

This project, the Adaptive Light Dimmer for the DC House, senses a room's light content and adjusts a lamp's light intensity accordingly, thus regulating the room's light content. The device is designed to work with renewable energy sources such as wind and solar energy. This would be useful in less developed countries where AC electricity is not well spread and renewable DC, such as solar, can be better utilized. It functions by using the TSL2561 light sensor to sense light, ATTiny85 microcontroller to output PWM to the LED driver, LT3795 LED driver to output current to an LED and LT3014 …

Automatic Standby Power-Saving Power Strip, Trung Nguyen

Electrical Engineering

The Standby Power Saving Power Strip improves on common power strip functionality. The project reduces the power loss from most electrical devices’ standby power mode, while retaining the convenience of leaving the devices plugged-in. The surge protector automatically recognizes when the plugged-in devices enter standby power mode. Then, it shuts off power to that device and automatically provides power back to the plugged-in devices, when turned on.

Solar Roller - Solar Powered Usb Charging Station, Aaron Bartfeld, Tanner Mjelde, Kaylan Naicker

Electrical Engineering

As the necessity for renewable energy increases, solar power becomes more and more prevalent. At the same time, as technology increases, the necessity for charging one’s electronic devices also increases. The Solar Roller merges solar energy with the ability to charge one's electronic device in one compact cart. The Solar Roller is a solar-powered USB charging station that allows people of all backgrounds to develop a better understanding of alternative fuels, while charging their USB device. It has a touch screen display that provides voltage levels of the battery as well as a TV that displays solar powered information. The …

Microgrid Protection Student Laboratory, Ian Hellman-Wylie, Joey Navarro

Electrical Engineering

To better prepare students for careers in the electric power industry, specifically in the discipline of power system protection, the Electrical Engineering Department at Cal Poly San Luis Obispo proposed an initiative calling for the creation of new laboratory curriculum that uses microprocessor-based relays to give students hands-on experience in the application of protection theory. This report describes the creation of a system that meets this need by providing a laboratory-scale power system that demonstrates the use of common protective relays and protection schemes. This system provides a platform for laboratory coursework using protective relays for transmission line, transformer, and …

General-Purpose Digital Filter Platform, Michael Cheng

Electrical Engineering

This senior project provides a platform for high-speed, general-purpose digital filter implementation. EE 459 currently implements digital filters using reprogrammable digital signal processor boards. These aging digital signal processors serially calculate each difference equation term. Operating at 1 Mega-sample per second, the new general-purpose platform simultaneously processes at least ten digital filtering difference equation coefficients. The platform also features an audio jack input and BNC connectors for viewing input and output signals. The filter digitizes single channel audio signals at 44.1 kHz sampling rate with 16-bit precision or 1 MHz sampling at 8-bit precision. The new reprogrammable platform includes a …

Remote Cable Gantry, Allen L. Bailey

Electrical Engineering

The Remote Cable Gantry is a robotic system that was initially intended to aid in the art of aerial videography. It was designed to enable novice and expert users alike to capture both video footage and audio from perspectives unachievable by current methods. This system uses a series of cables to control the position of a camera gimbal in a defined 3D space and, as a self-contained unit, is portable and easy to use. The Remote Cable Gantry offers a quiet, intuitive, and safe alternative to existing technology, which has been limiting the market and potential of aerial photography and …

Music Synthesizer Senior Project: Individual Report, Bryan Bellin

Electrical Engineering

No abstract provided.

Music Synthesizer Senior Project: Danalog, Vikrant A. Marathe

Electrical Engineering

The Danalog is a 25 key portable digital music synthesizer that uses multiple synthesis methods and effects to generate sounds. Sound varieties included three synthesis methods including FM, subtractive, and sample-based, with up to eight adjustable parameters, at least four effects, including reverb, chorus, and flange, with five adjustable parameters, and at least two note polyphony, and a five band equalizer. The user would be able to adjust these effects using digital encoders and potentiometers and view the settings on two LCD screens. The finals project was unable to meet the original design requirements. The FM synthesis method was primarily …

Danalog: Digital Music Synthesizer, Evan R. Lew

Electrical Engineering

The Danalog is a 25 key portable digital music synthesizer that uses multiple synthesis methods and effects to generate sounds. Sound varieties included three synthesis methods including FM, subtractive, and sample-based, with up to eight adjustable parameters, at least four effects, including reverb, chorus, and flange, with five adjustable parameters, and at least two note polyphony, and a five band equalizer. The user would be able to adjust these effects using digital encoders and potentiometers and view the settings on two LCD screens.

The finals project was unable to meet the original design requirements. The FM synthesis method was primarily …

Wireless Audio Bridge, Daniel L. Hodges

Electrical Engineering

Bluetooth, a wireless technology standard used to exchange data using radio transmissions, has made a significant impact on the audio technology industry, specifically the way people listen to music. This technology enables a wireless listening experience, eliminating the need for wires or cables between audio devices as previously required. Audio can transmit from a cellphone or laptop (an output device) to a pair of headphones or speakers (an input device) without any physical connection. Compared to alternative wireless listening solutions (i.e. FM transmitter, radio broadcast), Bluetooth offers greater reliability, audio fidelity, portability, and ease of use. To obtain this functionality, …

Baserock Bluetooth: Bi-Directional Bluetooth And 3.5 Mm Headphone Jack Compatibility Device, Jonathan A. Falco

Electrical Engineering

This project was proposed by a startup company from downtown San Luis Obispo called BaseRock. BaseRock sells a backpack containing subwoofers to allow the user to feel low frequencies of music. It is intended for concerts or personal use, listening to songs on an MP3. The main way the BaseRock backpack communicates with MP3s is via the headphone jack. With the introduction of the Apple iPhone 7 in September of 2016, BaseRock realized it was at a disadvantage. Millions of iPhone 7 owners and potential customers around the globe would no longer possess a headphone jack. BaseRock needs a Bluetooth-to-headphone …

Portable Dac And Headphone Amplifier For High Impedance Headphones, Kevin V. Thai

Electrical Engineering

The following paper contains an in-depth report on the design process of a portable DAC and Amplifier for high impedance headphones. The project brings portability into an audiophile’s world. This portable DAC and Class D amplifier takes USB data from a phone, converts it to analog, and amplifies the signal for high impedance headphones. First, the document contains motivations for the project: such as the necessity for such equipment, and who would use this product. Next, discussions of marketing considerations and customer needs bring together specifications. After, the report examines the project plan, overall functionality blocks, and estimated costs. Finally, …

Wax Bee Gone: A Safe, Effective Solution To Ear Wax Removal, Robert G. Shenon, Shanvir S. Dhinsa

Electrical Engineering

This project sought to combine conventional methods such as scraping and water pressure to removal ear wax, but with electronic automation to removal the potential for human error as much as possible. Through the use of a 9V battery, and Arduino microcontroller, DC motors, and other circuitry, this project has developed a prototype for a device that can properly remove ear wax without any discomfort or risk to the user. Much of this project involved learning how to properly manipulate and provide the necessary power requirements DC motors from an Arduino and a 9V battery. Additionally, creating a 3D printed …

Auxiliary Power System, Karianne Laplante, Nidia Vara, Eve Wassenaar, Carter Whittington

Electrical Engineering

The main objective for this project is to design and build a prototype for an all-electric SUV for the start-up company, Sharpell Technologies. This vehicle will comprise of the following configurations: auxiliary power system (APS), battery management system, battery pack wiring, CAN bus system, DC-DC charging converter, DC/DC auxiliary converter, instrument cluster, and motor controller/inverter. Each car configuration is a project assigned to a 2-4 student team; in total, eight EE senior projects and one ME project is produced. New lightweight batteries are also in the process of being developed to provide a viable electric source for the car. A …

Light Sensing Automated Blinds, Andrew B. Hodges, Ryan C. Flick

Electrical Engineering

This project is solving the problem of wasted energy within buildings and homes, because currently the lights turned on inside building do not utilize natural, ambient light from the sun. Rather than having unnecessary light from a light source, the automated light sensing smart blinds can sense the amount of light outside the window and in the room, and then adjust the angle of the blinds to save energy by utilizing the available outdoor light. This way, the light source will not be running at maximum power output while there is excess light coming through the window. This project aims …

Student Experimental Farm Smart Pathway Lighting System, Emily A. Whitaker, Vineal S. Singh, Edith Rodriguez

Electrical Engineering

This project works together with the Student Experimental Farm (SEF) and the DC House in order to install a smart lighting pathway system. This system will run off of DC power supplied by the solar panels connected to the DC House. This project tested and explored the group’s abilities to design and implement a full system run off of 48V DC. By installing this system it will greatly improve the ease for students to work at the SEF beyond daylight hours. The system will allow continuous dull lighting and will switch to full brightness once a person is detected. This …

Dc House Energy Management System, Zachary L. Eldredge, Zoe M. Hay

Electrical Engineering

In this work, a previously completed proof of concept for an Energy Management System (EMS) for the DC House project has been revised and re-implemented. The implemented design changes will improve the performance and reproducibility of the system. This new design of the EMS replaces the two-separate buck and boost DC-DC converters with a single bidirectional DC-DC converter to reduce components and improve efficiency. Analysis of the bidirectional DC-DC converter shows high efficiency especially at larger load currents. The code of the previous work was updated for smoother operation as well as to accommodate an LCD capable of displaying more …

Make Scents: Senior Project Report, Bruce Edward Mitchener Iii, Dennis Tsuker

Electrical Engineering

The purpose of this project was to create a smart air freshener. A complete user-friendly system that is programmable and simple to use for customers of all ages. Many constraints were met in order to achieve the final product and the necessary requirements. This Senior Project helps maintain a clean scented room of any size with its programmable functions to set spray times per the user’s request. Final system incorporates a user operated remote controller that catches the signal using an infrared sensor. The ease and simplicity of this air freshener makes it stand out in the competing market of …