Engineering Commons^™

Ac Direct Drive Led Lighting Using Low Cost Analog Components, Miles Head

Master's Theses

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 design a scaled-down physical AC LED direct drive system to validate the conclusions of methods for improving efficiency from a previous investigation that found minimizing voltage across the linear regulating MOSFET led to higher efficiency …

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 …

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 …

Power Supply For Driving High Power Leds With Wireless Control, Joshua C. Avery

Computer Engineering

This project is the design of a power supply for driving high power light emitting diodes (LEDs) with wireless control. The project is divided into two sections, the power supply for driving the LED lights, and the wireless control and fan power supply.

Wireless Led Motorcycle Jacket, Sean O'Brien

Electrical Engineering

In 2013 there were over 120,000 motorcycle fatalities in the U.S. alone, 73% of which were in the evening or during poor lighting conditions. Motorcyclists are at a disadvantage when it comes to their visibility on the road due to their size and location of lighting indicators. Because of this, motorcyclists are 82% more likely to be in an accident than other automobiles. One of the most common phrases among drivers involved in car vs motorcycle collisions is “I just didn’t see him."

Many products exist on the market to assist with visibility of motorcyclists including high-visibility clothing and gear …

Adaptive Automotive Lighting Systems, Marc W. Haeberlin

Master's Theses

Over the past few years, the use of LEDs within the automotive and avionic industries has increased due to their high efficiency, durability and wide range of light brightness. As the use of LEDs within these industries grows, a need for reliable, high performance drivers becomes more relevant. Companies are implementing LEDs for applications involving adaptive lighting or simple dimming features. This thesis shows implementation of various non-isolated analog converters integrated with digital dimmers to achieve these adaptive lighting systems. Adaptive lighting systems involve reading an input from an external source (brake pedal or steering wheel) and changing the brightness …

Piezoelectric Powered Led Street Reflector, Collin Shane Douglass

Electrical Engineering

In many areas of Washington, it rains for a majority of the year. During rainy weather it becomes difficult to see street lanes and dividers, causing hazardous road conditions. The Piezoelectric Powered LED Street Reflector solves this problem. The PPL Street Reflector modifies a street reflector with LED lights. These lights help drivers clearly see where dividers and street lines are in non-ideal weather conditions, such as rain, fog, and snow. The PPL Street Reflector capabilities include harvesting energy through the Piezoelectric Effect, creating a self-sustaining device with minimal maintenance.

Enhancing Gan Led Efficiency Through Nano-Gratings And Standing Wave Analysis, Gabriel M. Halpin

Master's Theses

Improving energy efficient lighting is a necessary step in reducing energy consumption.Lighting currently consumes 17% of all U.S. residential and commercial electricity, but a report from the U.S. Office of Energy Efficiency and Renewable Energy projects that switching to LED lighting over the next 20 years will save 46% of electricity used in lighting.GaN LEDs are used for their efficient conversion of electricity to light, but improving GaN efficiency requires optically engineering the chip to extract more light.Total internal reflection limits GaN LED performance since light must approach the chip surface within 23.6° of normal to escape into air.This thesis …

Off Grid Solar Powered Street Light, Justin Fang, Billy Pham

Electrical Engineering

Street lights are fixtures found in every city and serve the important purpose of illuminating the streets and keeping the roads safe for pedestrians and drivers. Current street lights are powered by the grid, power which is paid for by the taxpayers and could have been used to power homes instead. With this project, our goal is to design and implement an electric power system that collects and stores solar energy, and delivers power to an LED smart street light. The resulting system would reduce street light energy costs by 100% since they would not draw any power from the …

Solar Powered Led Lantern For Developing Countries, Lacy Billingsly Iii

Electrical Engineering

In recent years, both LED and solar technology have become the focus of sustainable energy. LED lighting uses significantly less power than its fluorescent competitor. Solar cells enable clean, natural, and portable power. As these two entities become more efficient at exponential rates, the hope for the wide use of off-grid lighting in less developed countries seemingly increases at the same rate. Currently, there has been a development of industry for portable solar powered lighting systems. Before designing a product, a study was conducted of current products on the market that aim to light dark homes. This study and design …

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.

The Design And Manufacture Of A Light Emitting Diode Package For General Lighting, Michael S. Krist

Master's Theses

Lighting technologies have evolved over the years to become higher quality, more efficient sources of light. LEDs are poised to become the market standard for general lighting because they are the most power efficient form of lighting and do not contain hazardous materials. Unfortunately, LEDs pose unique problems because advanced thermal management is required to remove the high heat fluxes generated by such relatively small devices. These problems have already been overcome with complex packaging and exotic materials, but high costs are preventing this technology from displacing current lighting technologies.

The purpose of this study is to develop a low-cost …

Passivation Of Polymer Light-Emitting Diodes, Stephen A. Fehrman

Electrical Engineering

This senior project investigates various methods of packaging polymer LEDs. The polymer LEDs fabricated in the EE 422 Polymer Electronics lab use calcium cathodes. While calcium acts as an excellent low work function electrode, it quickly oxidizes in the presence of oxygen or water. Additionally, the intrusion of water can degrade the OC1C10-PPV electroluminescent polymer and the PEDOT polymer. Therefore, in order to use these devices outside the inert atmosphere of a glove box, we must first apply a passivation layer that inhibits the deterioration of these materials.

For this project I will test two packaging methods. The first method …