Engineering Commons^™

Dc-Dc Converter For Harvesting Energy From An Exercise Bike, Henry Ureh, Chris Henry

Electrical Engineering

Create an efficient buck-boost converter that adapts to input voltage range from ~3.8V to 70V, and outputs 13.7V DC, the voltage required by a charge controller to charge a battery. The energy stored in the battery will be supplied back to the grid.

The cost of energy saved by the converter should eventually cover the initial price of the converter. The converter should help reduce the net power consumption of the exercise machines used in the Cal Poly gym

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 …

Pic Controlled Two-Band Stereo Audio Equalizer, Tim Brown

Electrical Engineering

The purpose of this project is to build a PIC (Peripheral Interface Controlled) controlled two-band stereo audio equalizer. The input audio from each stereo channel is separated into four different analog filters. The PIC has been programmed in BASIC and is used to route the audio signal to one of the four analog filters. Three of the filters have been preset to a certain frequency response (Jazz, Natural, and Bass), and the fourth filter has the unique ability to be controlled manually. Stereo potentiometers have been installed on the “Manual” filter to allow the user to change the frequency response …

Analysis & Design Of Improved Multiphase Interleaving Dc-Dc Converter With Input-Output Bypass Capacitor, Rudi Rudianto

Master's Theses

As the transistor count per chip in computer microprocessors surpasses one billion, the semiconductor industry has become more and more concerned with meeting processor’s power requirements. This poses a design challenge for the power supply module, especially when the processor operates at low voltage range. For example, the electrical requirement for the newest Intel microprocessors has exceeded 100A with an input voltage of approximately 1V. To overcome this problem, multiphase DC-to-DC converters encased in a voltage regulator module (VRM) have become the standard means of supplying power to computer microprocessor.

This study proposes a new topology for the multiphase DC-to-DC …

Advanced Thermosonic Wire Bonding Using High Frequency Ultrasonic Power: Optimization, Bondability, And Reliability, Minh-Nhat Ba Le

Master's Theses

Gold wire bonding typically uses 60 KHz ultrasonic frequency. Studies have been reported that increasing ultrasonic frequency from 60KHz to 120KHz can decrease bonding time, lower bonding temperature, and/or improve the bondability of Au metalized organic substrates. This thesis presents a systematic study of the effects of 120 KHz ultrasonic frequency on the reliability of fine pitch gold wire bonding. Two wire sizes, 25.4 and 17.8 μm in diameter (1.0 and 0.7 mil, respectively) were used. The gold wires were bonded to metalized pads over organic substrates with five different metallization. The studies were carried out using a thermosonic ball …

Low Voltage, Low Power, Bulk-Driven Amplifier, Shama Huda

Electrical Engineering Undergraduate Honors Theses

The importance of low voltage and low powered electronics is increasing with advances in medical electronics. This branch of electronics specifically requires low voltage and low power to make efficient innovative medical equipment. Low power electronics are also desirable because it conserves energy and power. This paper proposes a design of a differential in - differential our amplifier that uses a bulk-driven differential pair for the input pair. In addition, it also used bulk-driven current mirrors for the tail current sink and the active loads. The bulkdriven technique helps to achieve the low voltage design. 90nm CMOS technology was considered …

Micro-Scale Flapping Wings For The Advancement Of Flying Mems, Nicholas R. Coleman

Theses and Dissertations

This research effort presents conceptual micro scale air vehicles whose total dimensions are less than one millimeter. The initial effort was to advance the understanding of micro aerial vehicles at sub-millimeter dimensions by fabricating and testing micro scale flapping wings. Fabrication was accomplished using a surface micromachining process called PolyMUMPs™. Both rigid mechanical structures and biomimetic devices were designed and fabricated as part of this effort. The rigid mechanical structures focused on out of plane deflections with solid connections and assembling a multiple hinge wing structure through the aid of residual stress. These devices were actuated by double hot arm …

Optimization Of Gan Laser Diodes Using 1d And 2d Optical Simulations, Sean Richard Keali'i Jobe

Master's Theses

This paper studies the optical properties of a GaN Laser Diode (LD). Through simulation, the GaN LD is optimized for the best optical confinement factor. It is found that there are optimal thicknesses of each layer in the diode that yield the highest optical confinement factor. There is a strong relationship between the optical confinement factor and lasing threshold—a higher optical confinement factor results in a lower lasing threshold. Increasing optical confinement improves lasing efficiency. Blue LDs are important to the future of lighting sources as they represent the final color in the RGB spectrum that does not have a …

A Mems Multi-Cantilever Variable Capacitor On Metamaterial, Luke A. Rederus

Theses and Dissertations

Negative refractive index materials are an example of metamaterials that are becoming increasingly popular. Research into these metamaterials could possibly be the first steps toward bending electromagnetic radiation (i.e., microwaves, light, etc.) around an object or person. Split ring resonators (SRR) are classified as metamaterials that create an artificial magnetic response from materials with no inherent magnetic properties. Once fabricated, an SRR has a specific resonant frequency due to its permanent geometry. This research introduces a new concept of using a variable capacitive micro- electro-mechanical system (MEMS) device located at the gap of an SRR to mechanically alter the capacitance …