String Theory Lecture 3-Peruvian scientist Barton Zwiebach Cantor-Prof. Massachusetts Institute of Technology

Barton Zwiebach (full name Barton Zwiebach Cantor, born October 4, 1954) is a string theorist and professor at the Massachusetts Institute of Technology, born in Lima, Perú. Zwiebach's undergraduate work was in Electrical Engineering at the Universidad Nacional de Ingeniería in Peru, from which he graduated in 1977.
 His graduate work was in physics at the California Institute of Technology. Zwiebach obtained his Ph.D. in 1983, working under the supervision of Murray Gell-Mann. He has held postdoctoral positions at the University of California, Berkeley, and at MIT, where he became an assistant professor of physics in 1987, and a permanent member of the faculty in 1994.
 He is one of the world's leading experts in string field theory.
 He wrote the textbook A First Course in String Theory (2004, ISBN 0-521-83143-1), meant for undergraduates. Nationality Peru and United States
SOURCE: https://en.wikipedia.org/wiki/Barton_Zwiebach

1. Wave Mechanics-Instructor(s) Prof. Barton Zwiebach,Peruvian scientist MIT Course Number 8.05

Analysis of EMI characteristics of switched mode power supply and switching noise reduction methods Shin Hyo Sub Department of Semiconductor and Display Engineering Sungkyunkwan University

Analysis of EMI characteristics of switched mode power supply and switching noise reduction methods Shin Hyo Sub Department of Semiconductor and Display Engineering Sungkyunkwan University 

 This paper classifies sources of switching noise of switched mode power supply and methods to reduce the effect of them. In this study, conventional approach to apply auxiliary switch between switching node and output node is enhanced, by removing original rectifying circuit and by applying auxiliary switch between switching node and VSS node. When turn-on duration of the auxiliary switch was varied, small pulse width duration shows less noise reduction effect, on the other hand large pulse width duration shows more noise reduction effect. However power efficiency showed reverse trend with noise reduction effect, so there is a trade-off between noise reduction effect and power efficiency. The effect of adding RC and RL snubber in addition to the auxiliary switch was investigated. When RC snubber was added, switching node voltage showed maximum reduction. Conducted noise simulation with line impedance stabilization network also showed noticeable reduction of differential mode noise.
 Keywords: Switched mode power supply, EMI, Conducted noise, snubber, switching ringing noise.
LINK
https://www.mediafire.com/file/f00t9zi6xcxq4ng/ANALYSIS_OF_EMI_CHARACTERISTICS_OF_SWITCHED_MODE_POWER_SUPPLY.pdf/file

Design of Resonant LLC converters by scaled cloning- PROF.Sam Ben-Yaakov

This presentation explains how to scale a given “good” design of resonant LLC converters so it will meet the required specifications in terms of power level, input or output voltage or switching frequency.

A Single-Stage Asymmetrical Half-Bridge Flyback Converter with Resonant Operation -Chung-Yi Ting , Yi-Chieh Hsu -Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology

A Single-Stage Asymmetrical Half-Bridge Flyback Converter with Resonant Operation Chung-Yi Ting , Yi-Chieh Hsu , Jing-Yuan Lin ,and Chung-Ping Chen Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology.

 Abstract: This paper proposes a single-stage asymmetrical half-bridge fly-back (AHBF) converter with resonant mode using dual-mode control. The presented converter has an integrated boost converter and asymmetrical half-bridge fly-back converter and operates in resonant mode. The boost-cell always operates in discontinuous conduction mode (DCM) to achieve high power factor. The presented converter operates simultaneously using a variable-frequency-controller (VFC) and pulse-width-modulation (PWM) controller. Unlike the conventional single-stage design, the intermediate bus voltage of this controller can be regulated depending on the main power switch duty ratio. The asymmetrical half-bridge fly-back converter utilizes a variable switching frequency controller to achieve the output voltage regulation. The asymmetrical half-bridge fly-back converter can achieve zero-voltage-switching (ZVS) operation and significantly reduce the switching losses. Detailed analysis and design of this single-stage asymmetrical half-bridge fly-back converter with resonant mode is described. A wide AC input voltage ranging from 90 to 264 Vrms and output 19 V/ 120 W prototype converter was built to verify the theoretical analysis and performance of the presented converter.
Keywords: fly-back converter; zero-voltage-switching (ZVS); Variable-frequency-controller (VFC); single-stage
LINK:  https://www.preprints.org/manuscript/201805.0140/v1