Engineering Commons^™

3d Signal Strength Mapping Of 2.4ghz Wifi Networks, Brett D. Glidden

Electrical Engineering

Many commercial businesses operate out of multi-story office buildings. These companies often use many Wi-Fi access points to set up their own wireless network. IT personnel determine proper Wi-Fi access point placement using Wi-Fi strength maps. Conventional Wi-Fi strength maps only provide a two-dimensional view representing the wireless access point's effective range. The signal quality and strength measurements do not include changing vertical elevation. Efficient network layout in a multi-story building requires a system calculating signal quality metrics in three dimensions.

This project involves designing and prototyping a system to achieve 2.4GHz Wi-Fi signal quality measurements in a three-dimensional reference …

Grid-Tied Solar System, Virginia Yan

Electrical Engineering

Distribution level solar energy generation has gained importance and popularity, because it helps create a sustainable electricity system while reducing the harmful environmental impacts our current power systems have. This project proposes an alternative energy source, a laboratory-scale grid-connected photovoltaic system. A KC120-1 solar panel produces 120 Watts maximum. A grid-tied solar power inverter does DC-to-AC conversion and minimizes energy transfer losses. The inverter also has an anti-islanding feature, which senses a power outage and prevents back-feeding through isolating the circuit. The circuit breakers isolate electrical components and protect the circuit. Schweitzer Engineering Laboratories SEL-751 feeder protection relay and SEL-735 …

Comparison Of Organic And Inorganic Solar Photovoltaic Systems, Khulan Orgil

Electrical Engineering

This senior project report addresses the consumer’s need for accurate and easily accessible information when making a solar panel purchasing decision. Thus, the project analyzes and compares the costs and benefits of organic and inorganic photovoltaic systems during their life cycle. The cost comparison includes analysis of the environmental and economic costs of materials, production, installation, and disposal. The benefit comparison includes analysis of the economic, environmental, and social benefits accrued during the system’s lifetime. With the project’s data, consumers can make more informed decisions to fit their specific needs.

Dc-Dc 4-Switch Buck-Boost Converter For Energy Harvesting From Elliptical Machines, Alexander C. Samietz, Gustavo Guzman

Electrical Engineering

The senior project report documents the process of replacing the network of resistors inside an elliptical machine with a DC-DC buck-boost converter. The buck-boost DC-DC converter accepts a wide input range of 5-60 Volts, with an output of 36 Volts for the most efficient use of the already available microinverter. The microinverter reclaims the lost energy and safely distributes it back to the electrical grid. The addition of this project reduces heat emissions from wasted energy and shrinks the carbon footprint of its users.

Test Bench Design For The Fontana Gaf Facility, Dalton Paul Wunderlich

Electrical Engineering

This senior design project consists of designing and building a test bench set up in the GAF facility located in Fontana CA. The project creates an area where testing of different configurations of equipment takes place before implementing the equipment on the production line. Having this isolated environment allows the engineers and technicians to follow several design build test iterations on new systems. The design has the versatility to handle different equipment set ups and test a large quantity of diverse situations. The test bench implements Allen Bradley ControLogix, PLC-5, multiple Powerflex drives and multiple Kinetix servo drives simultaneously. The …

Investigating Efficiency Of Ac Direct Drive Of Led Lighting, Miles Davis Head

Electrical Engineering

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 develop a flexible simulation of a common AC LED system to find areas of significant power loss and attempt to improve them. This allows future versions of an AC LED system to start with major loss …

Portable High-Definition Audio Spectrum Analyzer, Alex Zahn, Jamie Corr

Electrical Engineering

The Portable High-definition Audio Spectrum Analyzer (PHASA) allows the user to visualize the audio frequency spectrum of an incoming line-level stereo audio signal. Upon pressing the touch screen spectrum graph, the PHASA displays the corresponding frequency and volume levels as well as crosshairs at the touched location. The PHASA features multiple left/right channel display modes— Left channel only, right channel only, both channels simultaneously, and the average between the two channels. The PHASA features multiple resolution display modes (standard-resolution and high-resolution) and multiple dynamics display modes (standard dynamics, averaging, and peak/hold). The PHASA accepts input audio via a 1/4" TRS …

Iridium Adc, Bill Blakely

Electrical Engineering

Today's modern digital audio systems are pushing performance boundaries. Most high quality audio digital to analog converters are capable of 24 bit, 96 kHz conversion. Professional audio interfaces frequently use 24 or 32 bit 192 kHz sample rates. These systems are able to achieve dynamic ranges greater than 100 dB, and distortion on the magnitude of single parts per million. This project proposes a high resolution analog digital converter (ADC) to measure and characterize these types of devices.

The proposed system will be capable of 24 bit conversion and an extended frequency range compared to the typical 20 Hz to …

Wind/Hydro Generator Simulator, Michael Timothy Djaja, Christopher James Rotsios

Electrical Engineering

The intention of this project is to make it easier for people without reliable access to electricity to implement their own sources of electrical generation. The ability to simulate different sources of generation allows people in need to find what source of generation will most properly meet their electricity needs. The goal of this project was to provide a wind or water flow profile from any area in the world and output a corresponding amount of power that would be expected from a small-scale wind or hydro generator. Due to difficulties with the microcontroller and incorrect sizing of components, this …

Design And Test Of Wide Input And Output Constant Current Led Driver, Kean Wee

Electrical Engineering

This senior project aims to provide design and test the performance of a DC-DC constant current LED driver for use in a larger DC smart building infrastructure. In this instance, a SEPIC topology is chosen to provide high efficiency output current at output voltages that can be above or below the input voltage. This is challenging since the same design must operate at similar efficiency for vastly different environmental conditions. As a part of a larger system, the design must be able to perform the given task consistently regardless of changes to the source and load power.

The design uses …

Versatile Usb Powered Turntable, Kyle P. Mccarry

Electrical Engineering

People enjoy vinyl music’s warm sound, user participation, and nostalgic feel, but the large physical size and seemingly immobile system requirements prevent vinyl turntables branching into digital music dominated realms. USB ports power many important everyday devices. A USB powered turntable increases record player adaptability, versatility, and portability thus expanding usable turntable scenarios. The manual turntable plays seven to twelve-inch vinyl at 33 1/3 or 45 rpm. It includes a stylus, magnetic phono cartridge, tonearm, 45-rpm adapter, motor, audio output, and several setting switches and knob for easy use.

Smart Espresso Machine, Hasham Ali, Justin L'Heureux, Hayden Yeung, Pei Hang Zhang

Electrical Engineering

With the recent “Internet of Things” trend, more and more home devices are connected to the Internet. Smart light bulbs, smart thermostats, smart door locks; just to name a few. These smart appliances enable users to view their status and control their settings remotely with just a few clicks on the smartphone. Moreover, the arrival of intelligent personal voice assistants such as Amazon Alexa revolutionized how users interact with these smart appliances. Nowadays, users are able to control these devices by just speaking.

If controlling smart devices is so easy, why not have your morning cup of joe be that …

Collision Avoidance Smartphone, Matt Columbres, Aaron Parisi, Joey Schnecker, Luis Wong

Electrical Engineering

There are many instances in day-to-day life where people cannot or would rather not pay full attention to their surroundings. Walking while preoccupied with a smartphone or walking while blind are excellent examples where technology could be used to make the task of avoiding 2collisions reactive, instead of proactive. A device which monitors a user’s surroundings and notifies the user when a potential collision is detected (and, additionally, notifying them as to where the obstacle is with respect to them) could be used to make walking distracted less of a hazard for the user and those around the user and …

Metrology Computer Redesign, Natalie Lizama, Melinda Ong, Mitchell Aiken

Electrical Engineering

We are M[EE]² and our project is to redesign Micro-Vu’s metrology computer (the Q16) with modern components and updated firmware. Metrology machines take high precision and high accuracy measurements, and a computer attached to each machine reads out the measurements. We will be redesigning the logic and display circuit boards on the Q16. The ports and communication methods with the machine will stay the same as it must be a drop-in replacement.

The motivation behind the redesign stems from the age of the current design. The current design was created in 1986, and has not had significant modifications since. …

Ewall Inverter Project, Andrew Douglas Tsau, Alex Lopez

Electrical Engineering

The objective of this project is to demonstrate the capabilities of a Raspberry Pi when used as a grid-tied, bi-directional power inverter for renewable energy storage applications. Due to its economical nature, this system would play a large role in the growing solar industry by making solar energy more accessible, affordable, and easier to install. The inverter uses a single-phase H-Bridge to generate a sine wave from a proprietary wall mounted battery. To improve power quality, an enhanced low pass filter is added to provide a better drop off to reduce extraneous harmonics. The system synchronizes this synthetic sine wave …

Dc House Solar Panel Cleaner, Sarahanne Heredia, Sophia Deguia

Electrical Engineering

Solar panels lose 0.05% of their power conversion efficiency per day due to soil accumulation, according to an experiment conducted by the University of California, San Diego in 2013 [18]. The project is an electro-mechanical cleaning system that effectively and efficiently cleans solar panels at set intervals. A drip irrigation system with spray jets was attached to a water pump and Arduino, both powered by the DC House Project solar panel battery. The DC House solar panel was the targeted panel set up for the project. Several components of the design could have been chosen more optimally for the system; …

Electric Upgrades - Supercapacitor Electric Bicycle, John Chen, Wilson Fletcher, Spencer Esparza

Electrical Engineering

Supercapacitors provide high current capabilities compared to conventional lithium-ion batteries, allowing for fast charging and discharging of electrical energy. This project seeks to test the benefits of supercapacitors in an electric bicycle unit in order to gain higher regenerative energy. The main components of the bicycle are its regenerative motor, supercapacitor array, and motor controller. Developing the project will provide data on the feasibility of using alternative battery storage and charging.

Passive Balancing Battery Management System For Cal Poly Racing's Formula Sae Electric Vehicle, Alvin Joseph Ha

Electrical Engineering

This senior project aims to replace the current battery management system (BMS) on Cal Poly’s Formula SAE electric vehicle with a more versatile, advanced, and reliable system. A BMS manages a rechargeable battery by ensuring the battery device operator’s safety, protecting battery cell integrity, prolonging battery lifetime, maintaining functional design requirements, and sending optimal usage information to the application controller. Passive balancing maximizes a battery pack’s capacity by dissipating excess energy through heat to regulate cell state of charge.

High-Bandwidth Iop Sensing Backscatter Transceiver, Mark Manuel

Electrical Engineering

This document describes the design and build of a mobile phone attachment that communicates with an ASIC embedded smart contact lens. The portable device enables patients and clinicians to conveniently and instantaneously measure intraocular pressure (IOP). The device replaces bulky and expensive benchtop RF synthesizer and signal analyzer machines required for communication to the smart contact lens into a portable and convenient device. The transceiver transmits VHF ISM band radio and can capture reflected backscatter On-Off-Keying modulated message signals at bandwidths from DC to 130MHz.

Induction Coil Power Generator, Steven Chi Li

Electrical Engineering

Over the years, society has evolved technologically to the point where we become dependent on technology. Today, nearly everybody have smartphone devices. This leads to the popularity of portable chargers since portable devices do not have a constant source of power. Even most portable chargers share the same problem as portable devices, which they both share a finite amount of battery power before needing to recharge at a power outlet. Ultimately, they are just temporary solutions to the problem of the lack of power. However, society assumes the abundance of electric power sources where they view them as an infinite …

Analysis Of Improved Multiphase Buck Converter, Usamah Riaz Ahmad, Scott Wu

Electrical Engineering

While the number of transistors per microprocessor is rapidly increasing, the power requirements of converters are getting more and more important. The amount of current is increasing, while at the same time the output voltage is steadily decreasing. Today’s boards are exceeding 100A, while the buck converters have their output voltage below 1 V. Due to these new power requirements, multiphase buck converters are becoming more popular. In addition, this topology is usually used with voltage regulator modules (VRM).

The TPS40090EVM-002 board was used as the original multiphase buck with an input voltage of 12 V and output voltage of …

Circuit Breaker Module, Garvin Yee, Yei Trinh

Electrical Engineering

The circuit breaker module for this design project is a proof of concept that demonstrates the functionality, feasibility, and attainability of a consumer grade power systems analysis device suitable for college laboratory use. The goal of this project was to create the final iteration of a module that has been developed and refined over the course of previous years. The Cal Poly Electrical Engineering Department intends to use this design to produce circuit breaker modules intended for fault analysis. With the current changes made to the previous modules, the current circuit breaker is lighter, safer, and more universally reproducible. The …

Microgrid Protection Student Laboratory: Human-Machine Interface And Scada Database, Nathan P. Martinez

Electrical Engineering

The electric utility system, a ubiquitous and fundamental component of modern life, has changed more in the last 20 years than the last 100. With more homes and businesses installing distributed energy resources (DERs) such as solar panels, battery storage, and other intermittent sources, massive changes need to take place in the electric transmission and distribution systems. Engineers must develop a new skill set for a modern utility industry. This project summarizes a component for a new laboratory class aimed at power engineering students at Cal Poly which supports the laboratory through the creation of a human-machine interface (HMI) and …

Digital Guitar Effects Pedal, Ian Charles Lang

Electrical Engineering

The Digital Guitar Effects Pedal assists guitarists in creating music by implementing several useful functions. The pedal takes an analog input signal from an electric guitar, performs digital operations on it, and outputs a modified analog signal to an external guitar amplifier. Pedal functions include: an easy-to-use instrument tuner, a looper which records and plays back music segments, a tap tempo mode allowing easy synchronization with other instruments, and various guitar effects (distortion, echo, and vibrato, among other examples). The pedal user interface displays the current selected function, and allows easy switching between effects.

Standalone Wireless Humming Music Synthesizer (Humsynth), Anna Shabrova, Chad Carlson

Electrical Engineering

The HumSynth is a voice controlled music synthesizer. Unlike the commonly found voice modulators on the market, this product uses a vocal input in place of the traditional keyboard interface. This allows the instrument to serve as an intuitive learning tool for those not proficient in music theory. By using their voice, the consumer is able to get a feel for different scales and keys additionally bypassing the physical learning curve of learning a traditional instrument. By the date of submission this project performs basic functions in recreating the pitch input but does not meet the full specs. The enclosure …

Electronic Drum Machine (E.D.M), Nyssa Marie Backes

Electrical Engineering

Many people argue that a drummer plays the most important role in a band of any genre. During live performances, the other band members rely on the drummer to keep the song moving forward at a proper steady pace. Even in recorded music, drums help listeners sing and dance along with their favorite songs. Thus, achieving success as a band, both in terms of recordings and live shows, absolutely requires a drummer. So, if a band does not have a drummer, and cannot afford the hefty cost of hiring a session drummer, a touring drummer, or both, how can they …