A Human Powered Micro-generator for Charging Electronic Devices

A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour of string pulling. It is concluded that this device can be beneficial to people with electronic devices that need off-grid charging

Linearized large signal modeling, analysis, and control design of phase-controlled series-parallel resonant converters using state feedback

This paper proposes a linearized large signal state-space model for the fixed-frequency phase-controlled series-parallel resonant converter. The proposed model utilizes state feedback of the output filter inductor current to perform linearization. The model combines multiple-frequency and average state-space modeling techniques to generate an aggregate model with dc state variables that are relatively easier to control and slower than the fast resonant tank dynamics. The main objective of the linearized model is to provide a linear representation of the converter behavior under large signal variation which is suitable for faster simulation and large signal estimation/calculation of the converter state variables. The model also provides insight into converter dynamics as well as a simplified reduced order transfer function for PI closed-loop design. Experimental and simulation results from a detailed switched converter model are compared with the proposed state-space model output to verify its accuracy and robustness

An optimized tuned mass damper/harvester device

Much work has been conducted on vibration absorbers, such as tuned mass dampers (TMD), where significant energy is extracted from a structure. Traditionally, this energy is dissipated through the devices as heat. In this paper, the concept of recovering some of this energy electrically and reuse it for structural control or health monitoring is investigated. The energy-dissipating damper of a TMD is replaced with an electromagnetic device in order to transform mechanical vibration into electrical energy. That gives the possibility of controlled damping force whilst generating useful electrical energy. Both analytical and experimental results from an adaptive and a semi-active tuned mass damper/harvester are presented. The obtained results suggest that sufficient energy might be harvested for the device to tune itself to optimise vibration suppression

Accurate Extraction of Noise Source Impedance of an SMPS Under Operating Conditions

An accurate measurement method to extract the common mode (CM) and the differential mode (DM) noise source impedances of a switched mode power supply (SMPS) under its operating condition is developed and validated. With a proper pre-measurement calibration process, the proposed method allows extraction of both the CM and the DM noise source impedances with very good accuracy. These noise source impedances come in handy to design an electromagnetic interference (EMI) filter for a SMPS systematically with minimum hassl

The History of the Development of the Rectenna

The history of the development of the rectenna is reviewed through its early conceptual developmental phases. Some selective aspects of the current solar power satellite rectenna development are examined

Creating a Portable MP3 Player Three-Band Graphic Equalizer and Amplifier for a Circuits Laboratory Final Project

At George Fox University, all engineering students are required to take the sophomore level circuits course. In an effort to more effectively engage the students in the course, a new final project was designed to leverage the interest in music and audio that is shared by undergraduate students. This paper details the design and implementation of a battery powered, three-band graphic equalizer and amplifier for a portable MP3 player or IPOD® and the associated labs and project that accompany it. There are three circuit design elements of the final project, the first teaching students how to use comparators to create a graphic display, the second detailing active filters, and the final lab describing peak rectifiers and the mixer that ties everything together. As a final project experience, each student is given a kit containing a PCB, a speaker, an on/off switch, a batteryholder, and every electronic component required to construct the final system. Students are also required to write a major lab report detailing the operation of the final project. After providing the experience one time, student engagement was noticeably higher, the results of the final project being significantly beyond the expectations of the course instructors