Engineering Commons^™

Portable 6 Lead 4 Electrode Ekg, Cody Magnuson, Wes Archbold

Electrical Engineering

This project focused on designing a small, portable, 6 lead 4 electrode electrocardiogram (EKG) machine with enough accuracy and resolution to successfully diagnose clinical issues. The electrical design used to measure signals originating from the heart can be broken up into three stages. The first stage is the human device interface. Next, is the analog block that filters out common mode noise and conditions the signal for digital encoding using instrumentation amplifiers, a right leg circuit, high pass, low pass, and an amplifier. This circuit filters all frequencies above and below the frequency band of meaningful data (1-160Hz), rejects signals …

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 …

Method For Selecting Coupling And By-Pass Capacitors In Multi-Stage Linear Circuits, Vladimir I. Prodanov, Dale Dolan

Electrical Engineering

A method for selecting a set of coupling and by-pass capacitors is presented. The approach uses short-circuit time-constant analysis and for a given −3 dB cut-off frequency minimises the total capacitance used. This study offers a derivation of design formulas and shows their use via examples.

Two Senior Projects: 2.4 Ghz, 40% Efficiency Radio Frequency Amplifier, Ieee Design Contest, & Design And Implementation Of A Software Costas Loop For Audio Frequencies, Robert J. Tong

Electrical Engineering

How to Read this Document:

This document combines two senior project reports. The first senior project documents designing a class AB RF amplifier. The second, discusses the design and implementation of a software Costas loop for audio frequencies. The first report begins on the next page, while the Costas loop report starts on page 24. The two reports are orthogonal from one another. It is not a prerequisite to read the RF amplifier report before reading the Costas loop report. This document is merely two reports combined into one document. The second report, about the Costas loop, was written as …

Uhf Rfid Antenna Impedance Matching Techniques, Kamron Sockolov, Dean Arakaki

Electrical Engineering

The modified T-match network uses planar inductive strips for conjugate matching Radio Frequency Identification (RFID) Integrated Circuits (RFICs). Narrow and broadband matching techniques and electromagnetic simulations are applied in [1] for specific designs. This paper extends these efforts through antenna element parameterization and design trade-off analysis. Narrow and broadband designs are fabricated; antenna input impedance and tag range tests confirm predictions.

Activsense Sidestick: A Force Sensing And Force Feedback Joystick, Kobbe Farwick

Electrical Engineering

As aircraft systems continue to become more integrated and fully electronic, hence fly-by-wire, the pilot is slowly losing the physical cues that were once relied upon for the safe operation of the aircraft. Many commercial airliners, such as Airbus, use passive sidesticks that integrate with the electronic flight controls system. These sidesticks move much like a gaming joystick which results in the pilot not having any “feel” for the aerodynamic forces present on the control surfaces. Without the force feedback of a mechanically linked control system the pilot could inadvertently stall the aircraft or place it into an unstable flight …

Lab-Scale Circuit Breaker Module For Power System Laboratories, Amanda Barley, Allen C. Scozzari, Joshua E. Chung

Electrical Engineering

In this project, a circuit breaker that can simulate different types of power system faults is redesigned, constructed, and tested. They will then be implemented in power systems laboratory courses at Cal Poly. The project’s goal is to improve a previous circuit breaker design to help students better visualize how faults affect power systems in the real world. Two main improvements are made to the previous circuit breaker design. The first improvement is to power the breaker with a typical wall outlet adapter instead of the DC source from the Cal Poly power systems laboratory test benches. This lets the …

Solid State Drive, Shaun A. Steele

Electrical Engineering

This project documents the design and implementation of a solid state drive (SSD). SSDs are a non-volatile memory storage device that competes with hard disk drives. SSDs rely on flash memory, a type of non-volatile memory that is electrically erased and programmed. The appeal of SSDs lies in the fact that they allow a fast, reliable, and durable memory storage device. The goal of this project is to have a working external SSD built from scratch.

Wireless Communication For Greenhouse Environment, Chris J. Lambert, Dean T. Lockman, Ian A. Nielsen

Electrical Engineering

Modern day population growth and global climate change requires high-yield agricultural systems that can function in harsh environments. Greenhouses can maintain temperature and humidity, while serving as a protective, nurturing alternative to vulnerable farm environments. With weather effects eliminated, greenhouses provide productive environments for experimental agriculture techniques such as hydroponics and aquaculture. These methods of agriculture, specifically aquaculture, require constant monitoring. The failure of electronic devices such as an air pump prove fatal to a fish population in a short time frame. In developing countries, agricultural locations may be a significant distance from a farmer’s home, with no internet or …

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 …

Smart Safeguard, Stephen J. Marrone

Electrical Engineering

Smart Safeguard is designed to provide people with an affordable device that will notify the authorities when the buyer gets in a car crash. The device will operate off the 12V car power that is present in every car and use an accelerometer to detect if an accident has occurred. If an accident is detected the device will proceed to light up and make a noise until the passenger pushes a button on the device. If the passenger doesn’t push the button within 15 seconds the device, which is wirelessly connected to the passenger’s phone, will initiate a text to …

Investigation Of Mimo Communications, Rodrigo Mendez Olea, William C. Tran, Patrick C. Kezer, Jean M. Whitmore

Electrical Engineering

This project focuses on the background of multiple input multiple output (MIMO) communication and its advantages over the other possible implementations. A background of wireless communication in regards to modulation types, information theory, antenna background and a hardware implementation using a VSA and VSG is provided. The theory is compared and verified with the hardware implementation with regards to the effect of the increase in the number of antennas and the parameter vector error magnitude.

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 …

Acceleration Amplitude Control System For Oscillating Silicon Oil Physics Experiment, Eric Chen

Electrical Engineering

This project is an ‘acceleration amplitude control system’ for use in an ‘oscillating silicon oil physics experiment’. The physics experiment has a tray of silicon oil. This tray must oscillate vertically at a specific amplitude (either at or just below the level for Faraday Waves). This control systems manages taking measurements of acceleration amplitude, and also manages correcting the shaker’s driving signal to obtain the correct acceleration. Features of the control system are designed for ease of use, because the system will mostly be operated by professor/ students without background knowledge in electrical engineering.

Hands On, Michael Le, Justin Remulla, Chris Menezes, Noah Beilin

Electrical Engineering

The goal is to design an extremely articulate smart glove, which acts a virtual reality controller. The smart glove will have gesture detection, which could include hand movements and/or combinations of finger movements to emulate mouse click or scroll, or digitally map out a hand for integrations with virtually reality softwares. This glove will have multiple accelerometer sensors on each finger and joint, connected to a single board running BLE MCU SoC in order to communicate with computer or mobile devices. The glove would connect to devices such as computers or phones using a Bluetooth dongle with applications in virtual …

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 …

Formula Sae Power Distribution Controller, Daniel Baron

Electrical Engineering

The Power Distribution Controller senior project aims to replace the current Power Distribution Module (PDM) on Cal Poly’s Formula SAE internal combustion vehicle with a more advanced, configurable, and reliable system. The Power Distribution Controller is a MOSFET based system that can be controlled through either controller area network or a parallel interface to distribute and control power from the vehicle’s battery to the several electrical devices on the car. The Power Distribution Controller also collects output voltage and current data, and communicates this data to the vehicle’s data logger. This will allow engineers to troubleshoot electrical problems on the …

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 …

Water Leak Detection System, Ryan T. Hanson

Electrical Engineering

The water supply shortage has increased in recent years due to overpopulation, climate change and obsolete water facilities, where deteriorated pipes cause most of the water leaks. The problem is not the size of the leak, but the time it takes to detect it. This paper presents the implementation of a system installed in the hydraulic facilities of a residence, to detect water leaks. The system consists of a water sensor installed by a water reservoir of interest, a microprocessor to interpret the data and evaluate whether it is a water leak or not, an SMS alert message, and an …

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 …