Engineering Commons^™

Auto-Tuning Antenna, John Chen, Jennifer Tighe

Electrical Engineering

Radio transmitters and antennas have differing impedances at the output and feedpoint, depending on frequency. Modern antenna tuning methods involve manual or automatic resistance and reactance network adjustment to match transmitter and antenna impedance. This reduces power reflections to the transmitter, but introduces losses and prevents full transmitter power from being radiated at the antenna. This project utilizes a variable length antenna element to tune and match transmitter and antenna impedances, allowing efficient power transfer to the antenna. The antenna length varies from 0 to 30.5 inches. The method involves an RF signal with a maximum power of 2 watts …

Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn

Electrical Engineering

As the demand for more devices to become wireless increases, there is a need for linear, efficient monolithic power amplifiers to deal with the variations in modulation of signals. With partial support from Cal Poly C3RP Grant #52268, this paper explains the implementation of and analyzes a circuit that actively biases a bipolar transistor to operate as a Class C amplifier. The Class C amplifier can maintain constant conduction angle over a range of output powers by using a Class B amplifier to force a scaled DC current vs. input magnitude curve on to a Class C amplifier. The knee …

Foce Medium Voltage Load Switcher, Eric Nelson, Sean Tolibas

Electrical Engineering

No abstract provided.

Imu Integration To The Cal Poly Spacecraft Attitude Dynamics Simulator Power System, Wayland Chan

Electrical Engineering

The Cal Poly Spacecraft Attitude Dynamics Simulator mimics the rotation dynamics of a spacecraft in orbit and acts as a test bed for spacecraft attitude control system development and demonstration. Prior to this project, the simulator measured its attitude dynamics from a total of seven sensors mounted on to the platform, including three micro-electromechanical system (MEMs) gyroscopes, and four motor encoders. This project entails the installation of an LN-200 high performance gyroscope, which will provide a greater measure of accuracy. The goal of this project is to design a power circuit that will integrate the LN-200 inertial measurement unit onto …

Rem Sleep Alarm, Shaun Kelsey, Brendon Soltis

Electrical Engineering

This paper explores the REM Sleep Alarm project that deals with the sleep cycle of the average human, and how it affects our ability to function when waking up in the morning.

The purpose of this project is to build a device that has the ability to wake a person up when they will feel the most rested. From research done, it appears that most people feel the most rested when woken up during the REM stage of their sleep cycle. Our goal is to have the device detect when the user is in this stage of sleep, determine how …

Variable Dc Voltage Wall Outlet For The Dc House Project, Michael Detmers, Tyler J. Blauvelt

Electrical Engineering

This senior project report will focus on explaining the design and operation of a variable DC wall outlet for use in the DC house. Testing will include the use of various loads using different input DC voltages not exceeding a maximum output of 90W.

The most important aspects of the outlet are to have a highly-efficient converter efficiency as well as system isolation from the main DC bus on the input. This report will outline the purpose and way of achieving isolation through use of a Flyback DC-DC converter. The user interface is the second significant aspect and details of …

Laser Cursor, Michael Liman

Electrical Engineering

A user controls a cursor on a computer screen using a laser pointer. A camera picks up the laser pointer’s position and sends the data to the computer to move the cursor in the correct position.

Exercise Bicycle Dc-Dc Converter For The Energy Harvesting From Exercise Machines Project, Ryan Rickard, Logan Stowe

Electrical Engineering

Project is a continuation of previous projects that seek an efficient DC to DC converter for the existing exercise bicycle system created by Mechanical and Electrical Engineering students. This DC-DC converter is to integrate with the wide range of DC voltages produced by the bicycle in order to produce a constant optimal voltage for charging a car battery. This converter will boost voltages when the bicycle outputs below the optimal voltage and buck voltages when above. The converter will take EHFEM one step closer to its overall and final goal of harvesting energy from the exercise machines in Cal Poly’s …

Solar Powered Backpack, Saagar Sabharwal, Tom Poonsopin

Electrical Engineering

One popular motto in electrical engineering today is “going green.” This project will convert the sun’s energy into reusable energy. The purpose of this senior project is to develop a solar powered backpack that can charge certain portable USB devices for students. Many students walk around campus with an iPod or cell phone, which has surely died or ran low on batteries at least once when needed most. This backpack will allow students to charge their devices “on the go.” When students walk or bike around campus, the solar panels attached to the backpack will allow recharging of their portable …

Programmable Household Led Light Fixture, Jordan Locano

Electrical Engineering

This report details the development and construction of a LED light fixture to be used for household lighting. This document details background information, design ideas, project specifications, production, assembly, testing, and conclusions involved with this project. The goals of this project is to design and build a cost-effective replacement for traditional room lighting that can perform better and last longer than traditional methods.

One-Pin 32 Khz Low-Power Crystal Oscillator, Aaron Plata-Ruiz

Electrical Engineering

This design is a one-pin, 32 kHz, low-power, crystal oscillator suitable for battery-operated systems. The design is based on a design published by Ali E Zadeh, “A Micropower, Battery-Operated, One-Pin Crystal Oscillator”, but redesigned for standard positive power supply configuration, which is suitable for typical n-well CMOS process.

Heart-Rate Monitoring Control System Using Photoplethysmography (Ppg), Wesley Nguyen, Ryan Horjus

Electrical Engineering

No abstract provided.

Design And Simulation Of V2g Bidirectional Inverter And Dc-Dc Converter, Allan Agatep, Mason Ung

Electrical Engineering

As plug-in hybrid electric vehicles (PHEV) become more popular, the utility companies are forced to feed the grid more electricity. However, these PHEVs are capable of providing power to the grid when they are parked serving as ancillary systems for grid regulation (V2G). Using a system based on photovoltaic (PV) technology, a design for a bidirectional inverter with LCL filter, and a bidirectional dc-dc with a constant current controller, was constructed using LTspice. Various papers were researched and analyzed to determine applicable designs for components. Simulations show the designs are capable of bidirectional power transfer. ETAP simulations show that delivering …

An Investigation Into Ultrasonic Communication For Near-Body Networks, Eric Joshua Escudero Jr., Gursewak Singh Rai

Electrical Engineering

The following report presents a study of body-area, free-space ultrasonic communication system. Two analog communication systems are investigated. The initial communications system setup relies upon the amplitude modulation (AM) techniques to transmit the signal. Such a system is prone to noise since the amplitude of the signal is directly affected by distance and the signal strength will deteriorate. The secondary communication system involves utilizing frequency modulation (FM). This method avoids the issue of losing information due to amplitude deterioration, but encounters delay issues. The main hardware components used in the approach outlined include ultrasonic transducers (UTs) used for both transmitting …

Programmable Solid State 12ax7 Triode Gain Stage, Ian Campbell

Electrical Engineering

This project demonstrates the viability of vacuum tube replacements made from solid state technology and programmable logic. A collection of operational amplifiers, digital converters and a field programmable gate array (FPGA) achieve this goal. The project emulates a 12AX7 vacuum tube triode as it would operate in a Fender Champ guitar amplifier. While the prototype works specifically with the Fender Champ, minor modifications could provide the versatility for operation in different amplifiers, including high end vintage hi-fi equipment. The addition of a micro controller into these amplifiers allows for the use of digital filtering and effects while not requiring modifications …

Wireless Sensor Network For Energy And Environmental Monitoring: Helping Old Buildings Go Green, Jacob Power

Electrical Engineering

Today, the rising cost of energy and social trend of “going green” has put increasing pressure on commercial property owners to improve the efficiency of their investments. There is good reason for this, too. In the State of California, office buildings represent the single largest user of energy in the commercial sector. This project consisted of the design, implementation, construction, testing, and deployment of a wireless sensor network for energy and environmental monitoring in retrofit commercial office installations. The analyzed data generated by this system can be used by building management and owners to identify areas of inefficiency within the …

Current Tracking Power Supply For Sensor Calibration, Joshua Brookley

Electrical Engineering

This report highlights the steps taken to design and develop a constant 5V power supply capable of tracking load current. The background of its previous design, its necessary specifications and steps taken to achieve specifications are highlighted throughout the report. The report also contains conclusions and final recommendations for the design chosen, including its strengths and drawbacks.

Discrete Alarm Clock, Travis Moore, Collin Barth

Electrical Engineering

The standard alarm clock, as used daily by millions worldwide, has clear room for modification and improvement. This paper documents an implementation that rectifies many of these flaws. Improvements include adjustable snooze length, an IR remote for ease of use, and an RF headset for discrete alarm use or potential incorporation into a device much like a hearing aid. The processes involved in creating a digital alarm clock, as well as the obstacles met in the implementation of the enhanced design, are detailed within.

Rfid Techniques For Passive Electronics, Ryan Behr, David Cobos

Electrical Engineering

No abstract provided.

Smooth Ternary Signaling For Deep-Submicron(Dsm) Buses, Robert Endicott Hanson, Ryan Ian Fullerton

Electrical Engineering

This project demonstrates the error mitigating effects of using a three-level “smooth ternary” signal on a Deep-Submicron(DSM) bus with large inter-wire capacitance. An RC circuit used to simulate and exaggerate (for easier testing) the charging and discharging of the DSM bus. An encoder stage translates binary input data into a three-level signal before sending it to the bus. A decoder stage then translates the three-level signal back to binary that is ideally identical to the original signal. Our results show that the three-level signal has much cleaner transitions than a traditional binary signal. A few glitches that appeared when decoding …

Elliptical Machine Dc-Dc Converter For The Energy Harvesting From Exercise Machines Project, Greg Hollister

Electrical Engineering

Designing a DC/DC Converter for the Cal Poly Energy Harvesting from Exercise Machines project requires special attention to the unique operating characteristics of the source and the load. An elliptical machine powered by a person exercising comprises the source, while an AC Inverter makes up the load. This project attempts to integrate the two devices with a custom DC/DC Converter in order to ultimately deliver power back into the power grid.

Led Spotlight, Eric Toussaint

Electrical Engineering

This report details the development and construction of an LED spotlight useable in a theatrical or architectural setting. In depth background information, initial design concepts, lighting instrument specifications, assembly, testing, and conclusions from results are highlighted in this document. Project goals include efforts to support more energy efficient lighting in the arts and general lighting applications and a decrease in overall costs for energy used in all dramatic and architectural lighting applications.

Aether, Thomas Cameron, Kristine Colton, Daren Childers

Electrical Engineering

Aether is a RC-style autonomous air vehicle that utilizes GPS positioning along with a wireless communication system to achieve a computer-controlled flight.

This report will incorporate the acquisition, design, integration, implementation and testing phases of the UAV development. Furthermore a discussion of troubleshooting as well as improvements for future projects will be included.

Hydro-Electric Generation System For The Dc House Project, Dennis Kwan, Mitchell Krug

Electrical Engineering

This paper focuses on the design, integration, and construction of a system that harnesses energy from flowing water. The system will be used in conjunction with the DC House Project. The proposed system employs a DC generator and DC-DC Boost-converter to provide electricity to the DC House at approximately 200-300W. Results of the testing and measurement show that the goal of the system is feasible, but currently limited. The generator could not output the specified power. Details of the design, along with ideas for further improvement, are presented in this report.

Wireless Energy Transfer, Ryan Sasur

Electrical Engineering

Phones are now an integral component in the daily lives of people. Smartphones give access to movies, internet, and even books. This versatility and increased use can also lead to a shorter battery life. A phone with video viewing capabilities will be a heavy load on the unit’s battery. With phones utilizing 3G and 4G technology, even heavier demands are placed on the battery. As technology improves even further to provide for a larger entertainment experience on the phone, this could also lead to further battery degradation if the current battery situation isn’t addressed. To have a fully operational phone …