DOCSLIB.ORG

Feedback Control: an Invisible Thread In

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Feedback Control: an Invisible Thread In COREL By Dennis S. Bernstein he history of technology is a rich and fascinat- The Escapement ing subject, combining engineering with eco- For Mercury there is, beyond the correction at leap nomic, social, and political factors. Technology year, provision for a secondary correction after 144 seems to advance in waves. Small advances in years by setting the wheel M forward 1 tooth. In the ar- science and technology accumulate slowly, gument of Mercury there is an annual deficit of 42′5″, sometimes over long periods of time, until a so that the dial should be set forward 2/3° annually critical level of technological success and economic advan- with a residual correction of 1° in 29 years. Ttage is achieved. The last century witnessed several of these — Giovanni di Dondi, describing the proce- waves: automobiles, radio, aircraft, television, and comput- dure for maintaining his astronomical clock ers, each of which had a profound effect on civilization. completed in 1364 [Gimpel, 1976, p. 165] Woven into the rich fabric of technological history is an The Kelantese approach to time is typified by their co- invisible thread that has had a profound effect on each of conut clocks—an invention they use as a timer for these waves and earlier ones as well. This thread is the idea sporting competitions. This clock consists of a half co- of feedback control. Like all ideas, feedback control impacts conut shell with a small hole in its center that sits in a technology only when it is embodied in technology; it is not pail of water. Intervals are measured by the time it tied to any specific technological innovation or invention. takes the shell to fill with water and then sink—usually The purpose of this article is to describe technological in- about three to five minutes. The Kelantese recognize novations that either use feedback control or allow feedback that the clock is inexact, but they choose it over the control to be exploited. While remarkable in their simplicity, wristwatches they own. these inventions are profound in their impact on technology. —[Levine, 1997, p. 93] In fact, we shall show that these innovations played a crucial In the early 15th century, the Western world was only role in facilitating the truly great waves of technological and dimly aware of the outlines of the world at large. As sailing scientific development, namely, the Scientific Revolution, the Industrial Revolution, the Age of Aviation, the Space Age, and The author ([email protected]) is with the Aerospace Engi- the Age of Electronics. These innovations are the escape- neering Department, 1320 Beal St., University of Michigan, Ann Ar- ment, the governor, the aileron, the gyro, and the amplifier. bor, MI 48109, U.S.A. 0272-1708/02/$17.00©2002IEEE April 2002 IEEE Control Systems Magazine 53 technology improved, Portuguese ships explored the un- but this method was not very accurate. The consequences charted coast of Africa, a daring exploit. It was a full 70 years of getting lost at sea were extremely serious and included before da Gama rounded the southern tip of Africa and the ship’s crew starving to death or dying of scurvy, as well reached India in 1498. This age of exploration included the as the ship being destroyed on rocky shores during foggy accidental Western discovery of the New World and affected weather. indigenous civilizations for better or worse around the The problem of determining longitude was eventually globe. solved by the mechanical clock. The hero of that story is In his quest to reach China, Columbus used a sec- John Harrison (1733-1766), a British clockmaker who spent ond-century map of Ptolemy, which underestimated the 30 years designing, building, and refining what are consid- size of the earth. Fortunately for Columbus, he discovered ered the most exquisite and innovative mechanical time- a way station (and obstacle) en route. One difficult aspect pieces ever built. of ocean journeys was the problem of navigation, in partic- Before the advent of the mechanical clock, time was mea- ular, that of determining longitude at sea. Rough estimates sured by means of water clocks, hourglasses, sundials, grad- of distance could be obtained by dead reckoning, which in- uated candles, and many other devices. All of these had volved a compass for determining direction and a means deficiencies in their operation and accuracy. In the last part for timing an object floating by the ship to estimate speed; of the 13th century, an alternative technology arose, the me- Clocks G.B. Airy, “On the disturbances of pendulums and M. Kesteven, “On the mathematical theory of clock balances, and on the theory of escapements,” Trans. escapements,” Amer. J. Physics, vol. 46, no. 2, pp. 125-129, Cambridge Phil. Soc., vol. III, part 1, pp. 105-128, 1830. 1978. W.J.H. Andrewes, Ed., The Quest for Longitude, 2nd. ed. D.S. Landes, Revolution in Time: Clocks and the Making of Cambridge, MA: Harvard Univ., Collection of Historical the Modern World, rev. ed. Cambridge, MA: Harvard Scientific Instruments, 1998. Univ. Press, 2000. A.A. Andronov, A.A. Vitt, and S.E. Khaikin, Theory of A.M. Lepschy, G.A. Mian, and U. Viaro, “Feedback control in Oscillators. Oxford: Pergamon Press, 1966. Reprinted by ancient water and mechanical clocks,” IEEE Trans. Educ., New York: Dover, 1987. vol. 35, no. 1, pp. 3-10, 1992. J.E. Barnett, Time’s Pendulum: From Sundials to Atomic R. Levine, A Geography of Time. New York: Basic Books, Clocks, the Fascinating History of Timekeeping and 1997. How Our Discoveries Changed the World. San Diego, CA: Harcourt Brace, 1998. H.A. Lloyd, Some Outstanding Clocks over Seven Hundred Years 1250-1950. London: Leonard Hill, 1958. F.J. Britton, The Escapements: Their Action, Construction, and Proportion. Chicago, IL: Hazlitt, undated. Reprinted K. Maurice and O. Mayr, The Clockwork Universe: German by Arlington: Arlington Books, 1984. Clocks and Automata, 1550-1650. Washington, D.C.: Smithsonian Institution, 1980. C.M. Cipolla, Clocks and Culture 1300-1700. New York: Norton, 1978. J.C. Pellaton, Watch Escapements, 3rd. ed. London: NAG Press, undated. G. Dohrn-van Rossum, History of the Hour: Clocks and Modern Temporal Orders. Chicago, IL: Univ. of Chicago L. Penman, Practical Clock Escapements. Shingle Springs, Press, 1996. CA: Clockworks Press Int., 1998. H.B. Fried, The Watch Escapement. New York: Columbia J.H. Reid, “The measurement of time,” J. Roy. Astron. Soc. Communications, 1974. Canada, vol. 66, no. 3, pp. 135-148, 1972. W.J. Gazely, Clock and Watch Escapements. London: A. Roup and D.S. Bernstein, “On the dynamics of the Heywood, 1956. escapement mechanism of a mechanical clock,” in Proc. F. Gies and J. Gies, Cathedral, Forge, and Waterwheel: Conf. Decision and Control, Phoenix, AZ, Dec. 1999, pp. Technology and Invention in the Middle Ages. New 2599-2604. York: Harper Perennial, 1994. A.V. Roup, D.S. Bernstein, S.G. Nersesov, W.M. Haddad, and J. Gimpel, The Medieval Machine: The Industrial V. Chellaboina, “Limit cycle analysis of the verge and Revolution of the Middle Ages. New York: Penguin, foliot clock escapement using impulsive differential 1976. equations and Poincare maps,” Proc. American Control Conf., Arlington, VA, June 2001, pp. 3245-3250 C. Schwartz and R. Gran, “Describing function analysis using MATLAB,” IEEE Contr. Sys. Mag., vol. 21, pp. 19-26, D. Sobel and W.J.H. Andrewes, The Illustrated Longitude: Aug. 2001. The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. New York: Walker, 1998. M.V. Headrick, Clock and Watch Escapement Mechanics. [Online] 1997. Available: C. Sturridge, Director, Longitude, DVD or VHS, Aug. 2000. http://mvheadrick.free.fr/clocklinks.html J.E.D. Williams, From Sails to Satellites: The Origin and L. Jardine, Ingenious Pursuits: Building the Scientific Development of Navigational Science. New York: Oxford Revolution. New York: Doubleday, 1999. Univ. Press, 1992. 54 IEEE Control Systems Magazine April 2002 chanical clock. This technology had advantages, but it was of interacting components. The speed at which the clock not uniformly better. Mechanical clocks were heavy, expen- runs depends on the dynamics that arise from this interac- sive, large, and often less accurate than earlier technolo- tion. In particular, the period of the limit cycle arises from gies. Clock towers in Europe employed full-time caretakers the coefficients of restitution and friction, as well as the iner- who used a sundial for periodically resetting the clock, tia of the various components. while some early wristwatches had a built-in compass and The verge-and-foliot clocks were usually large and con- sundial. structed of hand-wrought iron. Blacksmiths were enlisted to At the heart of every mechanical clock lies a regulator. build them, and large towers were constructed to support While early clocks kept time poorly, gradual improvements eventually allowed mechani- cal clocks to keep time with better accuracy At the heart of every mechanical than previous devices such as sundials. The earliest regulator was the verge-and-foliot clock lies a regulator. escapement, which dates from around 1283. Unfortunately, the inventor of this device is unknown, but it them. The driving weight alone often weighed 1,000 lb. Al- is clear that during this period many craftsmen sought to at- though these were not especially accurate clocks, to the ex- tain steady, reliable motion by using gears and levers driven tent that they did not warrant a minute hand, it is by the force of falling weights. The problem was to develop a noteworthy that the verge-and-foliot escapement was the device with a precise terminal (steady-state) velocity to only mechanical escapement that we know of from the time serve as the clock speed.
Load more

Recommended publications
  • Control Engineering for High School Students and Teachers: an Online Platform Development
    Control Engineering for High School Students and Teachers: An Online Platform Development Farhad Farokhi and Iman Shames Contents Report ............................................ 1 1 Introduction . 1 2 Courses . 1 3 Interviews . 2 4 Educational games . 3 5 Remote laboratory . 4 6 Conclusions and future work . 5 Appendix .......................................... 6 A Example course 1: Feedback theory . 6 B Example course 2: Models . 9 C Example course 3: On/off control . 12 D Remote laboratory (RLAB) manual . 13 1 Introduction Based on our teen years and feedback from many of our colleagues and friends, we believe that the control engineering, although being a major building block of automated system in many processes and infrastructures, is a fairly alien subject to the students, parents, and teachers. Therefore, there is a need for introducing feedback control and its application to high school students and their teachers to recruit the next generation of engineers and scientists in this field. We also believe that the academic community has a responsibility to disseminate the information cheaply, if not freely, to a wide range of interested audience, be it students, parents, or teachers, across the globe. This way, we can guarantee that people from different socio- economic backgrounds and in different countries can make informed decisions regarding their careers and those of their friends and families. Motivated by these needs, in this project, we have attempted at developing an online platform for the students and their educators to read about the control engineering, watch lectures by researchers from academia and industry, access interviews with successful people in the control engineering community, and play online games to test their understanding and to possibly learn about the applications of the automatic control.
    [Show full text]
  • EE C128 Chapter 10
    Lecture abstract EE C128 / ME C134 – Feedback Control Systems Topics covered in this presentation Lecture – Chapter 10 – Frequency Response Techniques I Advantages of FR techniques over RL I Define FR Alexandre Bayen I Define Bode & Nyquist plots I Relation between poles & zeros to Bode plots (slope, etc.) Department of Electrical Engineering & Computer Science st nd University of California Berkeley I Features of 1 -&2 -order system Bode plots I Define Nyquist criterion I Method of dealing with OL poles & zeros on imaginary axis I Simple method of dealing with OL stable & unstable systems I Determining gain & phase margins from Bode & Nyquist plots I Define static error constants September 10, 2013 I Determining static error constants from Bode & Nyquist plots I Determining TF from experimental FR data Bayen (EECS, UCB) Feedback Control Systems September 10, 2013 1 / 64 Bayen (EECS, UCB) Feedback Control Systems September 10, 2013 2 / 64 10 FR techniques 10.1 Intro Chapter outline 1 10 Frequency response techniques 1 10 Frequency response techniques 10.1 Introduction 10.1 Introduction 10.2 Asymptotic approximations: Bode plots 10.2 Asymptotic approximations: Bode plots 10.3 Introduction to Nyquist criterion 10.3 Introduction to Nyquist criterion 10.4 Sketching the Nyquist diagram 10.4 Sketching the Nyquist diagram 10.5 Stability via the Nyquist diagram 10.5 Stability via the Nyquist diagram 10.6 Gain margin and phase margin via the Nyquist diagram 10.6 Gain margin and phase margin via the Nyquist diagram 10.7 Stability, gain margin, and
    [Show full text]
  • IT Legacy Article Compendium
    An IT Legacy Booklet March 2016 IT Legacy Article Compendium 1 INTRODUCTION – LOWELL A. BENSON, EDITOR Write a Book? How about an autobiography? Shortly after the Information Technology (IT) Legacy Committee was formed, Dick Lundgren began to write Legacy articles for the VIP Club newsletter. During the committee’s decade of volunteering, several other committee members have also written Legacy associated newsletter items. This booklet1 is a collection of those VIP Club newsletter articles. The first several articles are the history of the Legacy Committee as we felt our way through the quagmire of gathering documents and hardware artifacts and then cataloging them. So, to some degree, this is both a book and the IT Legacy Committee’s autobiography. This book complements our December 2015 ‘Article for the Month’. That too was a booklet: Measuring Success = Volunteer Hours; recapping a decade with summaries of over 100 on-line IT Legacy articles. I dedicate this document to James 'Rapp' Rapinac who passed away 23 January 2016. Rapp was a steadfast supporter of our legacy initiatives and a good friend. LABenson If you are using Adobe reader; clicking on any section in the table of contents will get you there. 2 TABLE OF CONTENTS 1 Introduction – Lowell A. Benson, editor ......................................................................................... 1 3 2006, First Year Articles ................................................................................................................. 8 3.1 March 2006 – Richard Lundgren ...........................................................................................
    [Show full text]
  • Aircraft Propellers
    U.S. WORKS PROGRESS ADMINISTRATION BIBLIOGRAPHY OF A E R 0 N A U T I C S Part 27 - Aircraft Propellers Compiled from the INDEX OF AERONAUTICS of the INSTITUTE OF THE AERONAUTICAL SCIENCES 30 Rockefeller Plaza New York City The Index and Bibliographies have been prepared by workers under the supervision of the U.S. WORKS PROGRESS ADMINISTRATION Cecil A. Ross Senior Project Supervisor Project 465-97-S-S1 (Formerly 165-97-6055) 19 3 7 FOREWORD This bibliography is one of a series which aims to cover a large part of aeronautical literature. It is pub­ lished by the U. S. Works Progress Administration Project 465-97-3-21 (formerly 165-97-6055) under the sponsorship of the New York City Department of Docks with the cooperation of the Institute of the Aeronautical Sciences. Request for Additions The Institute of the Aeronautical Sciences which is directing the U. S. Works Progress Administration staff of workers will appreciate receiving additional references, corrections and criticism, so that the bibliographies will be.more helpful when issued in final form. Request for Copies The bibliographies have been prepared with funds allotted by the U. S. Works Progress Administration. They may not be sold. Persons and organizations wishing to procure copies may apply for them by letter, stating the use for which they are needed. When it is possible to prepare additional copies such requests will receive first consideration. Robert R. Dexter Aeronautical Engineer Address all correspondence to: John R. Palmer Managing Project Supervisor U- S. Works Progress Administration 5111 R.C.A.
    [Show full text]
  • Download Chapter 161KB
    Memorial Tributes: Volume 3 HENDRIK WADE BODE 50 Copyright National Academy of Sciences. All rights reserved. Memorial Tributes: Volume 3 HENDRIK WADE BODE 51 Hendrik Wade Bode 1905–1982 By Harvey Brooks Hendrik Wade Bode was widely known as one of the most articulate, thoughtful exponents of the philosophy and practice of systems engineering—the science and art of integrating technical components into a coherent system that is optimally adapted to its social function. After a career of more than forty years with Bell Telephone Laboratories, which he joined shortly after its founding in 1926, Dr. Bode retired in 1967 to become Gordon McKay Professor of Systems Engineering (on a half-time basis) in what was then the Division of Engineering and Applied Physics at Harvard. He became professor emeritus in July 1974. He died at his home in Cambridge on June 21, 1982, at the age of seventy- six. He is survived by his wife, Barbara Poore Bode, whom he married in 1933, and by two daughters, Dr. Katharine Bode Darlington of Philadelphia and Mrs. Anne Hathaway Bode Aarnes of Washington, D.C. Hendrik Bode was born in Madison, Wisconsin, on December 24, 1905. After attending grade school in Tempe, Arizona, and high school in Urbana, Illinois, he went on to Ohio State University, from which he received his B.A. in 1924 and his M.A. in 1926, both in mathematics. He joined Bell Labs in 1926 to work on electrical network theory and the design of electric filters. While at Bell, he also pursued graduate studies at Columbia University, receiving his Ph.D.
    [Show full text]
  • Review of Feedback Systems
    CHAPTER 1 Review of Feedback Systems Marc Thompson Dr. Marc Thompson leads us to an appreciation of how the world has learned about FEEDBACK (negative) over the years, so we can understand how to do better feedback in our systems. /rap Introduction and Some Early History of Feedback Control A feedback system is one that compares its output to a desired input and takes corrective action to force the output to follow the input. Arguably, the beginnings of automatic feedback control 1 can be traced back to the work of James Watt in the 1700s. Watt did lots of work on steam engines, and he adapted 2 a centrifugal governor to automatically control the speed of a steam engine. The governor comprised two rotating metal balls that would fl y out due to centrifugal force. The amount of “ fl y-out ” was then used to regulate the speed of the steam engine by adjusting a throttle. This was an example of proportional control. The steam engines of Watt ’ s day worked well with the governor, but as steam engines became larger and better engineered, it was found that there could be stability problems in the engine speed. One of the problems was hunting , or an engine speed that would surge and decrease, apparently hunting for a stable operating point. This phenomenon was not well understood until the latter part of the 19th century, when James Maxwell 3 (yes, the same Maxwell famous for all those equations) developed the mathematics of the stability of the Watt governor using differential equations. 1 Others may argue that the origins of feedback control trace back to the water clocks and fl oat regulators of the ancients.
    [Show full text]
  • Science and the Instrument-Maker
    r f ^ Science and the Instrument-maker MICHELSON, SPERRY, AND THE SPEED OF LIGHT Thomas Parke Hughes SMITHSONIAN STUDIES IN HISTORY AND TECHNOLOGY • NUMBER 37 Science and the Instrument-maker MICHELSON, SPERRY, AND THE SPEED OF LIGHT Thomas Parke Hughes Qmit/isoDian Ij;i^titution 'PJ^SS City of Washington 1976 ABSTRACT Hughes, Thomas Parke. Science and the Instrument-maker: Michelson, Sperry, and the Speed of Light. Smithsonian Studies in History and Technology, number 37, 18 pages, 9 figures, 2 tables, 1976.-This essay focuses on the cooperative efforts between A. A. Michelson, physicist, and Elmer Ambrose Sperry, inventor, to produce the instr.umentation for the determination of the speed of light. At the conclusion of experiments made in 1926, Michelson assigned the Sperry in­ struments the highest marks for accuracy. The value of the speed of light accepted by many today (299,792.5 km/sec) varies only 2.5 km/sec from that obtained using the Sperry octagonal steel mirror. The main problems of producing the instrumentation, human error in the communication of ideas to effect that in­ strumentation, a brief description of the experiments to determine the speed of light, and the analysis and evaluation of the results are discussed. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's report, Smithsonian Year. Si PRESS NUMBER 6I41. COVER: A. A. Michelson and Elmer Ambrose Sperry. Library of Congress Cataloging in Publication Data Hughes, Thomas Parke. Science and the instrument-maker. (Smithsonian studies in histoi7 and technology ; no. 37) Supt.
    [Show full text]
  • UNIT CONVERSION FACTORS Temperature K C 273 C 1.8(F 32
    Source: FUNDAMENTALS OF MICROSYSTEMS PACKAGING UNIT CONVERSION FACTORS Temperature K ϭ ЊC ϩ 273 ЊC ϭ 1.8(ЊF Ϫ 32) ЊR ϭ ЊF ϩ 460 Length 1 m ϭ 1010 A˚ ϭ 3.28 ft ϭ 39.4 in Mass 1 kg ϭ 2.2 lbm Force 1 N ϭ 1 kg-m/s2 ϭ 0.225 lbf Pressure (stress) 1 P ϭ 1 N/m2 ϭ 1.45 ϫ 10Ϫ4 psi Energy 1 J ϭ 1W-sϭ 1 N-m ϭ 1V-C 1Jϭ 0.239 cal ϭ 6.24 ϫ 1018 eV Current 1 A ϭ 1 C/s ϭ 1V/⍀ CONSTANTS Avogadro’s Number 6.02 ϫ 1023 moleϪ1 Gas Constant, R 8.314 J/(mole-K) Boltzmann’s constant, k 8.62 ϫ 10Ϫ5 eV/K Planck’s constant, h 6.63 ϫ 10Ϫ33 J-s Speed of light in a vacuum, c 3 ϫ 108 m/s Electron charge, q 1.6 ϫ 10Ϫ18 C SI PREFIXES giga, G 109 mega, M 106 kilo, k 103 centi, c 10Ϫ2 milli, m 10Ϫ3 micro, ␮ 10Ϫ6 nano, n 10Ϫ9 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Source: FUNDAMENTALS OF MICROSYSTEMS PACKAGING CHAPTER 1 INTRODUCTION TO MICROSYSTEMS PACKAGING Prof. Rao R. Tummala Georgia Institute of Technology ................................................................................................................. Design Environment IC Thermal Management Packaging Single Materials Chip Opto and RF Functions Discrete Passives Encapsulation IC Reliability IC Assembly Inspection PWB MEMS Board Manufacturing Assembly Test Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies.
    [Show full text]
  • MT-033: Voltage Feedback Op Amp Gain and Bandwidth
    MT-033 TUTORIAL Voltage Feedback Op Amp Gain and Bandwidth INTRODUCTION This tutorial examines the common ways to specify op amp gain and bandwidth. It should be noted that this discussion applies to voltage feedback (VFB) op amps—current feedback (CFB) op amps are discussed in a later tutorial (MT-034). OPEN-LOOP GAIN Unlike the ideal op amp, a practical op amp has a finite gain. The open-loop dc gain (usually referred to as AVOL) is the gain of the amplifier without the feedback loop being closed, hence the name “open-loop.” For a precision op amp this gain can be vary high, on the order of 160 dB (100 million) or more. This gain is flat from dc to what is referred to as the dominant pole corner frequency. From there the gain falls off at 6 dB/octave (20 dB/decade). An octave is a doubling in frequency and a decade is ×10 in frequency). If the op amp has a single pole, the open-loop gain will continue to fall at this rate as shown in Figure 1A. A practical op amp will have more than one pole as shown in Figure 1B. The second pole will double the rate at which the open- loop gain falls to 12 dB/octave (40 dB/decade). If the open-loop gain has dropped below 0 dB (unity gain) before it reaches the frequency of the second pole, the op amp will be unconditionally stable at any gain. This will be typically referred to as unity gain stable on the data sheet.
    [Show full text]
  • History of Nonlinear Oscillations Theory in France (1880–1940)
    Archimedes 49 New Studies in the History and Philosophy of Science and Technology Jean-Marc Ginoux History of Nonlinear Oscillations Theory in France (1880–1940) History of Nonlinear Oscillations Theory in France (1880–1940) Archimedes NEW STUDIES IN THE HISTORY AND PHILOSOPHY OF SCIENCE AND TECHNOLOGY VOLUME 49 EDITOR JED Z. BUCHWALD, Dreyfuss Professor of History, California Institute of Technology, Pasadena, USA. ASSOCIATE EDITORS FOR MATHEMATICS AND PHYSICAL SCIENCES JEREMY GRAY, The Faculty of Mathematics and Computing, The Open University, UK. TILMAN SAUER, Johannes Gutenberg University Mainz, Germany ASSOCIATE EDITORS FOR BIOLOGICAL SCIENCES SHARON KINGSLAND, Department of History of Science and Technology, Johns Hopkins University, Baltimore, USA. MANFRED LAUBICHLER, Arizona State University, USA ADVISORY BOARD FOR MATHEMATICS, PHYSICAL SCIENCES AND TECHNOLOGY HENK BOS, University of Utrecht, The Netherlands MORDECHAI FEINGOLD, California Institute of Technology, USA ALLAN D. FRANKLIN, University of Colorado at Boulder, USA KOSTAS GAVROGLU, National Technical University of Athens, Greece PAUL HOYNINGEN-HUENE, Leibniz University in Hannover, Germany TREVOR LEVERE, University of Toronto, Canada JESPER LÜTZEN, Copenhagen University, Denmark WILLIAM NEWMAN, Indiana University, Bloomington, USA LAWRENCE PRINCIPE, The Johns Hopkins University, USA JÜRGEN RENN, Max Planck Institute for the History of Science, Germany ALEX ROLAND, Duke University, USA ALAN SHAPIRO, University of Minnesota, USA NOEL SWERDLOW, California Institute of Technology,
    [Show full text]
  • Genios De La Ingeniería Eléctrica
    Genios de la Ingeniería Eléctrica COLECCIÓN GIGANTES Genios de la Ingeniería Eléctrica De la A a la Z Jesús Fraile Mora Fundación Iberdrola • 2006 • Patronato de la Fundación Iberdrola Presidente: D. Íñigo de Oriol Ybarra Vicepresidente: D. Javier Herrero Sorriqueta Patronos: D. Ricardo Álvarez Isasi D. José Ignacio Berroeta Echevarría D. José Orbegozo Arroyo D. Ignacio de Pinedo Cabezudo D. Antonio Sáenz de Miera D. Ignacio Sánchez Galán D. Víctor Urrutia Vallejo Secretario: D. Federico San Sebastián Flechoso Colección Gigantes Genios de la Ingeniería Eléctrica. De la A a la Z. © Jesús Fraile Mora © Fundación Iberdrola C/ Serrano, 26 - 1.ª 28001 Madrid Director de la Colección: José Luis de la Fuente O´Connor Editora: Marina Conde Morala ISBN: 84-609-9775-8 Depósito legal: M. 11.849-2006 Diseño, preimpresión e impresión: Gráficas Arias Montano, S. A. 28935 Móstoles (Madrid) Impreso en España - Printed in Spain Reservados todos los derechos. Está prohibido reproducir, registrar o transmitir esta publicación, íntegra o parcialmente, salvo para fines de crítica o comentario, por cualquier medio digital o analógico, sin permiso por escrito de los depositarios de los derechos. Los análisis, opiniones, conclusiones y recomendaciones que se puedan verter en esta publicación son del autor y no tienen por qué coincidir necesariamente con los de la Fundación Iberdrola. AGRADECIMIENTOS Quienquiera que se dedique a un trabajo de investigación histórica de la guisa de éste, se convierte en una pesadilla para los biblioteca- rios. Han sido muchos los años que me he dedicado a hurgar en los fondos antiguos de diversas bibliotecas, en busca de libros y revistas de todo tipo, por lo que he tenido tiempo de convivir con archi- veros y bibliotecarios que soportaron con paciencia y buen humor todas mis depredaciones.
    [Show full text]
  • Loop Stability Compensation Technique for Continuous-Time Common-Mode Feedback Circuits
    Loop Stability Compensation Technique for Continuous-Time Common-Mode Feedback Circuits Young-Kyun Cho and Bong Hyuk Park Mobile RF Research Section, Advanced Mobile Communications Research Department Electronics and Telecommunications Research Institute (ETRI) Daejeon, Korea Email: [email protected] Abstract—A loop stability compensation technique for continuous-time common-mode feedback (CMFB) circuits is presented. A Miller capacitor and nulling resistor in the compensation network provide a reliable and stable operation of the fully-differential operational amplifier without any performance degradation. The amplifier is designed in a 130 nm CMOS technology, achieves simulated performance of 57 dB open loop DC gain, 1.3-GHz unity-gain frequency and 65° phase margin. Also, the loop gain, bandwidth and phase margin of the CMFB are 51 dB, 27 MHz, and 76°, respectively. Keywords-common-mode feedback, loop stability compensation, continuous-time system, Miller compensation. Fig. 1. Loop stability compensation technique for CMFB circuit. I. INTRODUCTION common-mode signal to the opamp. In Fig. 1, two poles are The differential output amplifiers usually contain common- newly generated from the CMFB loop. A dominant pole is mode feedback (CMFB) circuitry [1, 2]. A CMFB circuit is a introduced at the opamp output and the second pole is located network sensing the common-mode voltage, comparing it with at the VCMFB node. Typically, the location of these poles are a proper reference, and feeding back the correct common-mode very close which deteriorates the loop phase margin (PM) and signal with the purpose to cancel the output common-mode makes the closed loop system unstable.
    [Show full text]