Engineering Commons^™

Power Distribution:Protection Analysis, Avneet S. Samra

Electrical Engineering

The objective of this project is to build a radial distribution system that operates on a lower voltage. The system consists of a transmission line protected by a SEL-351 Relay, a three- phase transformer protected by a SEL-587 Relay, and a three-phase induction motor protected by a Cooper Form 6 Controller. The SEL-351, SEL-587, and the Cooper Form 6 Controller are microprocessor-based relays that are used to provide protection under faulted conditions. When a fault is detected in the system, the closest upstream relay sends a trip signal to its assigned local breaker. The SEL-351 provides overcurrent protection for the …

Electric Smart Load Meter, Johnny Tran

Electrical Engineering

This project details the design of an electric meter that reads the signals of any device plugged into an outlet and displays cost readings that may potentially reduce power consumption. The sensor monitors whether a plugged in device continuously consumes power after completely charging up. For a charging device, the current remains constant until the device reaches 100% charge. Once the device becomes fully charged, the current discontinues for proper power usage. A unique aspect of the meter is that it displays cost per hour, day, and year. Displaying the cost per unit of time creates awareness for customers, potentially …

Garage Door Security System, Trevor Lehr, Austin Williams

Electrical Engineering

This project focuses on the design and build of a low cost system that monitors garage doors and transmits their state to a receiver unit placed at a convenient location inside the user’s house. This provides the user with the ability to monitor their garage doors from the comfort of inside their home without having to go outside and look at the garage. The receiver unit includes a screen to display system information and LEDs to make it easy to view the garage door’s status from a distance. The system has great enough range to place the receiver at any …

Designing A Power Distribution System For The Arce 257 Revit Structural Model, Reid Wilhelm

Electrical Engineering

The construction industry needs engineers. Mechanical, electrical, and plumbing engineers, better known as MEPs, comprise a large number of employees who design and assist in the building of commercial structures. In particular, electrical engineers design power distribution systems for these buildings, including the power, lighting, low voltage, and fire protection subsystems.

Here at Cal Poly, architectural engineers enrolled in ARCE 257 create authentic structural plans for a fictitious two-story structure. This senior project transforms these structural plans into an architectural model and creates a power distribution system for the entire building. This is done through a building information modeling (BIM) …

Active Contact Lens - Low Power Backscattering Sensor-To-Antenna Integration Circuitry, Caleb B. Porter

Electrical Engineering

The Active Contact Lens measures the cornea-scleral radius of the wearer’s eye, which correlates to intraocular pressure (IOP), Glaucoma’s primary indicator. IOP varies throughout the day, and is drastically different from person to person, so constantly measuring it over a period of a few days can provide individualized tracking of the disease’s development and will help doctors develop personalized treatment schedules to treat the disease more precisely.

The Active Contact Lens sensor measures strain, based on the cornea-scleral radius, and reports the results wirelessly, to allow monitoring of an individual’s IOP over time. The lens is powered similarly to a …

Rapid Battery Exchange (Rbx), Daniel Rostom

Electrical Engineering

Electric vehicles have begun to hit the main stream market, with sales raising form under 20,000 in 2001 to over 110,000 per year since 2014 [1]. With new models hitting the market every year, and more people becoming conscious about their fossil fuel usage, this trend will only continue until there are more electric vehicles than combustion vehicles on the road. A major drawback of electric vehicles is their limited range, and relatively long recharge times. Even with advancements in battery charging speed, such as the Tesla super charger, able to provide up to 90 miles of range in just …

Tilt-Rotor Drone, Benjamin Stone, Zachary Crandall

Electrical Engineering

A drone is defined a "an unmanned aircraft that can fly autonomously[2]." In the year 2016, there exist many applications for small scale drones. Drones, having had primarily military applications, now have use in hobby robotics, photography, and even in surveying. But drones have not yet been perfected and still have room for much improvement. Several problems with drones come in the form of battery life, stability, and size. Large drones can fit many sensors and probes, but are heavy and have less flight time. For autonomous drones, stability can be an issue even though there exist many stable drones. …

A Stroke Therapy Brace Design, Evan Kirkbride

Electrical Engineering

Victims of stroke often have difficulty with rehabilitation. With limited movement on their affected arm, patients often do not want to move much for physical therapy. In this project, we design a robotic brace that helps stroke patients move their arm more effectively in a reaching or pulling motion. By giving patients more movement in their affected arm than they would have otherwise, patients gain more from rehabilitation. The brace also adapts to the patient’s needs, providing more inclination or resistance as needed for their physical therapy. This kind of therapy engages patients rather than relying on their likely dwindled …

Cal Poly Supermileage Electronic Fuel Injection, Alexander Pink

Electrical Engineering

Cal Poly Supermileage is a student-run engineering club that builds prototype gasoline vehicles optimized maximum fuel-efficiency. To power their vehicles, the Supermileage team makes use of single-cylinder, 4-stroke, electronically fuel-injected (EFI) gasoline engines. This report details the development, iterative design & test cycles, and integration of an EFI system for the Supermileage club. This project develops an EFI system that interfaces to the most common types of sensors found in the low-power Supermileage-range of engines, including throttle-position sensors, manifold absolute pressure sensors, gear-tooth hall-effect sensors, variable-reluctance position sensors, engine coolant temperature sensors, intake air temperature sensors, and exhaust oxygen sensors. …

Design And Implementation Of A Three Dimensional Printer Using A Cylindrical Printing Process, Brandon Hoy

Electrical Engineering

Many 3D printers utilize a Cartesian (XYZ) printing process. Implementing a polar coordinate printer providing a faster printing method and introduces new printing algorithms, increasing printing efficiency. This cylindrical 3D printer applies a circular-moving baseplate and a heating printer head (extruder) moving radially and vertically. A processor accepts pre-processed polar data points and transpose the appropriate programmed printing commands to the motors units. The extruder also has a control loop, keeping the temperature inside the desired range. This prototype prints using polylactic acid (PLA) filament. Additionally, a display screen updates every second the: printing time, extruder temperature, and status notifications.

Camera Stabilizer, Nathaniel Bryan, Sean Chappell, Danielle Williams

Electrical Engineering

The goal of this project is to create an affordable camera stabilizer (the “stabilizer”) for consumers to use with cell phones or GoPro cameras. The stabilizer compensates for two axes, pitch and roll, as well as vertical movement. The system (currently only compatible with one cell phone model) is handheld and uses a combination of brushless DC motors, an Inertial Measurement Unit (IMU), and a microcontroller to compensate for the operator’s movements, stabilizing the phone for nonshaky, high quality video recording. The stabilizer provides a lowcost alternative to professional stabilization solutions employed in the production of featurelength films; the system …

Solar Generation's Impact On Fault Current, Kody Heppner

Electrical Engineering

California is paving the road for other states with the capacity of solar installations for residential and commercial entities. The added capacity of solar generation to the state's electric grid has an impact on power flow and fault currents. This project looks at the impact of solar installations on fault currents. Feeders with added residential rooftop solar and larger commercial solar installations may impact the system differently than a large, utility-sized solar installation. This project looks at the impact of both cases on the magnitude of fault current during many different fault types and locations that can occur within a …

Car Safe, David Van Workum

Electrical Engineering

The Car Safe project helps protect parents and caretakers from the dangers associated with leaving children in hot vehicles. The device supports parents through notifying them of the child’s wellbeing and status while within an automobile. Specifically, the device monitors the child’s ergonomic experience and the spatial proximity between the caretaker and child. Car Safe utilizes this information and determines if the child finds himself in a dangerous environment. Due to its compact design, the device functions independently of a specific car seat design, allowing customers to integrate Car Safe in the car seat environment of their choosing.

Energy Harvesting From Exercise Machines Buck-Boost Dc Dc Converter With The Lt8705 Controller, Ryan Matteo

Electrical Engineering

In order to increase sustainability and save money, the Energy Harvesting from Exercise Machines (EHFEM) system uses human supplied energy to self-power exercise equipment such as spin bikes, elliptical trainers, ergometers, etc. This document covers the design and implementation of a Buck-Boost DC-DC converter using the LT8705 controller into the EHFEM system. This project improves upon the overall efficiency of the Buck-Boost Converter designed by past groups working on the EHFEM system.

Transformer And Motor Protection Scheme, Bijan Vakilifathi

Electrical Engineering

No abstract provided.

Critter Sitter: Weight Sensing Pet Door, Shelby Richardson

Electrical Engineering

Martin Kaliski is a typical pet owner. He currently houses both cats and a dog. In order to keep from having to constantly let his pets out in the middle of the night he has installed a pet door into his home. All was well and good until early one morning Martin woke up to the sound of his Pomeranian barking violently. He ran downstairs to see what the problem was. He not only found his dog standing there but also a wild raccoon. The raccoon had slipped into the house in the early morning and was rummaging through the …

Analog Vlsi Circuit Design: Linear Voltage Regulator, Brett Colteaux, Kirstie Fung

Electrical Engineering

The project outlined in this report is the design, layout, and routing of a linear voltage regulator using Cadence VLSI (very-large-scale integration) software. The design specifications for this regulator are as follows: input voltage range of 5V + 1V, load current capabilities of 150mA, and output voltage range of 1.15V to 3.3V. Furthermore, the design of this circuit was broken into three main sub-circuits: an error amplifier, bandgap reference circuitry, and biasing circuitry for the bandgap. Together, these sub-circuits integrated to make the final design.

Research for different topologies for a voltage regulator was done and the Brokaw bandgap reference …

Integration Of Sel Relays To Provide Motor, Transmission Line, And Transformer Protection, Christopher Ewing, Bryce Keefer

Electrical Engineering

The objective of this project is to familiarize the performers with the principles of operation of the Schweitzer Engineering Laboratories (SEL) protective relays in both normal and fault conditions. The SEL-587, SEL-311L and SEL-710 microprocessor-based relays are used to provide protection for a system composed of transformers, simulated transmission lines and a 3-phase induction motor. Each of these relays provides protection by sending a trip signal to local breakers upon sensing a fault condition. The SEL-587 provides overcurrent and differential protection for a 3-phase transformer, while the SEL-311L provides differential and distance protection for a transmission line, and negative sequence. …

Exertion Control, Travis Taylor

Electrical Engineering

Current wearable fitness devices give the user after-the-fact fitness data, but little real-time feedback. Exertion Control, a new wearable device, continuously measures the user’s heart rate, creates a heart rate target, and helps the user reach it. This project completes the senior design and master’s thesis requirements and contains two milestones. The senior design product continuously measures the wearer’s heart rate and logs it with a user-friendly interface. This data models the heart’s exertion response and recovery response. The master’s thesis device refines the closed control loop with the user to give them a workout optimized to fit their needs.

Automatic Water Pump Controller, Alam D. Salguero, Kyle Russell Marquez Weeks

Electrical Engineering

In countries including Indonesia, Mexico, Guatemala, and El Salvador, a city water authority supplies the clean water and pumps it into large ground-level storage tanks. A resident’s water pump then pumps the water to a water tank on top of his/her house. When the water level in the ground-level storage tank becomes too low, the pump siphons air and shuts down, requiring a resident to manually prime the water pump to get it running again. Residents struggle to monitor the water level of the tanks effectively and keep the pump running properly. To remedy the issue, the Automatic Water Pump …

Underwater Optical Wireless Audio Transceiver, Angel Ayala

Electrical Engineering

Scuba diving carries risks that can endanger lives. Many of these risks are preventable. However, an underwater communication system can increase a diver’s safety. Along with providing safety, an underwater communication device can enhance the scuba diver’s enjoyment.

A low cost underwater optical wireless audio transceiver is designed. The project consists of the off-the-shelf parts that uses a microphone and speaker to transmit and receive sound. The project uses the concepts of visible light communications and pulse width modulation to transmit and receive sound. Although sound is commonly transmitted through ultrasound methods, visible light communications has several advantages. Visible light …

Led Slackline, Kristina Forystek

Electrical Engineering

A Slackline is a nylon rope that uses tension to suspend itself above ground. Slacklines are usually tied between two trees while the user walks across the line. Slacklining provides a daytime activity as user vision weakens after the sun goes down. A LED slackline allows users to practice tight roping at night. The lights let the user know when they perform well. The slackline uses a three axis system to determine how much the user moves. The slackline senses how much the user shakes in three dimensions and then relays it back to the LEDs. If the user shakes …

Micro-Inverter Improvement For The Energy Harvesting From Exercise Machine Project, James Ralston

Electrical Engineering

The Energy Harvesting from Exercise Machines (EHFEM) project at California Polytechnic State University consists of several different projects coming together to add human generated power to the grid. This project focuses on implementing a more efficient micro-inverter. The micro-inverter used to convert DC to AC voltage requires up to 5 minutes before the conversion process begins. This time lag significantly diminishes the power produced from an exercising individual. Research of micro-inverters approved by the CEC introduces desirable micro-inverters, available for use in California, to the EHFEM project. Testing the two most desirable micro-inverters found from research allows for quantifying of …

Active Charge Balancing For Cardiac Stimulation, Maci Miri

Electrical Engineering

Worldwide, there are about 3 million people who have pacemakers, with 10,000 new implantations of ICD’s each month. [heart.org] Due to the gravity and importance of the function that ICD’s provide, these devices must be extremely reliable and highly effective. However, because of the high tolerances of IC manufacturing, stimulation circuits for pacemakers may be slightly unmatched and over time, may have a net DC charge applied to the tissues in the heart. Extra charge pumped into body tissues is dangerous for the patient’s health; the pH of the tissue can be raised and corrosion of the stimulating electrodes may …

Robotic Overbed Table, Jonathan Lantz

Electrical Engineering

Traditionally overbed tables have simple and cheap designs, yet contain many disadvantages compared to the design proposed in this report. Disabled or bedridden persons, often require the use of a bedside table either in hospital environments or at home. Unfortunately, many modern overbed tables require the user to get out of bed and move in order to adjust and position the table. Incorporating a singlebutton control panel that allows the user to make adjustments and access other features independently, creates more accessible product. Integrated subsystems must control all motors and interfaces with an easy access control panel in order to …

Rf Power Harvesting Rectenna, Jimmy Tang, Raymond Phu, Tom Geranios, Benjamin Muñoz

Electrical Engineering

Sustainability is one of today's primary engineering objectives. This principle involves system design that minimizes environmentally harmful energy emissions and resource consumption, and maximizes renewable energy practices [1]. Communication antennas transmit wireless signals that can be converted into usable energy. The Rectenna system described in this report, shown in Figure 1, was designed to accomplish this energy conversion, with -5dBm (316µW) minimum power at the rectifier input. Since typical ambient signal power is in the -70dBm (0.1nW) range, the proposed system could only convert passive, relatively high-power microwave band AC signals to DC. The Rectenna system was designed for 1.9GHz …

Solar-Powered Hot Tub, Jonathan Peterson, Anthony Zepeda

Electrical Engineering

This paper discusses the design and implementation of a solar-powered hot tub. The concept of this project was to design an independently-operated hot tub powered by a 12V rechargeable battery, charged during the day by a single 400W solar panel. For this purpose, a twenty-year-old name-brand hot tub was purchased, in used condition. The plumbing, AC electrical wiring, and mechanical pumps were all removed and replaced with new components to meet our design specifications. Additionally, a solar water-heater was designed and integrated into the system to directly apply the sun’s heat to water pumped in and out of the tub, …

Usb-Powered Turntable "Turn T", Gerardo Sevilla, James Lougaris

Electrical Engineering

No abstract provided.

Faraday Rechargeable Battery System, Alex Gasper, Bret Omsberg

Electrical Engineering

The modern electronic age has given birth to a variety of innovative and hand-held devices that are carried with the consumer nearly 24 hours a day, seven days a week. The one shortfall of these devices is their energy storage, or in most cases, a battery. The Faraday Rechargeable Battery System is a unique system that will generate electricity through rotational movement of a tire. This can be a bike, a car, or any other transportation vehicle that uses wheels for movement. The kinetic energy that is engendered either by the user or an engine can then be converted into …