1 Bogatin Enterprises, Dr. Eric Bogatin W 110 th Terr. Olathe, KS Voice: Fax: Training for Signal Integrity and Interconnect Design What Really Is Inductance? By Dr. Eric Bogatin Bogatin Enterprises Oct 30, 1999 Reprinted with permission from PB Design Magazine, March 2000 Introduction There is not a single person involved with signal integrity and interconnect design who has not used the term inductance at one time or another. Yet, very few engineers use the term correctly. This is fundamentally due to the way we all learned about inductance in high school or college physics or electrical engineering. Traditionally, we learned about inductance and how it related to flux lines in coils. Or we learned about integrals involving magnetic field densities. While all of these explanations may be perfectly true, it doesn't help us on a practical level. How many boards have you designed that have coils in them? We have not been trained to apply the concepts of inductance to the applications we face daily, related to interconnects in packages, connectors or boards. If you really want to understand what inductance is, at an intuitive level, and use it to help improve the performance of your products, forget what you've been taught in school, and read on. ounting Field ines First, recognize that there is this fundamental entity, called magnetic field lines that surrounds every current. If you have a straight wire, colored red, for example, and send a current, like 1 Amp, through it, there will be concentric circular magnetic field lines created around the wire, as illustrated in figure 1. You can imagine walking along the red wire and counting the specific number of field lines that completely surround it.
2 page - 2 of 10 urrent section of wire Figure 1 Surrounding a current carrying conductor are concentric circular magnetic field lines. These field lines have a specific direction. To determine the direction, we use the familiar right hand rule. Point your thumb in the direction of the current and your fingers curl in the positive direction of the field lines. In what units would you count the field lines? We count pens in units of gross. There are 144 pens in a gross. We count paper in units of reams. There are 500 pages in a ream. We count apples in units of bushels. How many apples are there in a bushel? I don't know, but I know there is some number of apples. ikewise, we count the number of magnetic field lines around a current carrying conductor in units of Webers. I don't know how many field lines are in a Weber, but there is some number. As you would predict, if you double the current in the red wire to 2A, you will double the number of Webers of magnetic field lines that are around it. Inductance is fundamentally related to the number of magnetic field lines around the wire per amp of current in the wire. The units we use to measure inductance is Webers per Amp. One Weber/Amp is given the special unit, Henry. For most interconnect structures, when we describe their inductance, it is typically such a small fraction of a Henry, it is more common to use the units of a nano Henry. A nanohenry, typically abbreviated as nh, is a measure of how many Webers of field lines we would count around a conductor per amp of current through it. Why Inductance Plays Such An Important Role. A second property of magnetic field lines is that when the number of field lines around a wire changes, for whatever reason, there will be a voltage created
3 page - 3 of 10 across it. The voltage created is directly related to how fast the number of field lines, N, change: V = N/ t. Since inductance is related to the number of field lines around a wire per amp of current, the number of field lines is really N = x I. The voltage created, or induced, across a wire can be related to the inductance of the wire and how fast the current in it changes: V = I/ t. This is why inductance, in general, is something to be reduced, as it contributes to noise whenever the current changes, as when a signal switches. Because the voltage induced depends on how fast the current changes, we sometimes call the noise created when the current switches through an inductance, switching noise or delta I noise, or ground bounce. Delta I noise across a conductor is completely unbiased about whose current created the field lines, whether it is the field lines from its own currents or another conductor's current. If we happened to have an adjacent current near the red wire, some of the field lines from this second wire may surround the red wire. If the current in the second wire changes, it will cause a voltage to be created across the red wire. When it is another conductor in which the current changed, we usually call the induced noise in the adjacent conductor, cross talk. To be able to analyze real world problems that involve multiple conductors, we need to be able to keep track of all the various currents which are sources of field lines. The effects are the same, its just more complicated when there are many conductors, each with possible current and magnetic field lines. It is to describe the possible combinations of conductor pairs that the various flavors of inductance come in. Self And Mutual Inductance In addition to the red wire and its current and field lines in the above example, suppose there were to be another wire, a blue wire, with its own current, field lines and inductance. We bring it close to the red wire. When we count the field lines around the red wire, we will get a different number depending on the current in the blue wire. If the currents are in the same direction, bringing the blue wire close to the red wire will have us count a higher number of field lines around the red wire. But if we keep track of what currents created what field lines, we can keep straight the influence of each conductor. When we count field lines, we want to label the magnetic field lines that come from the wire's own currents, separate from the magnetic field lines that come from another wire's currents. To distinguish the source of the field lines, we use the term self to refer to the field lines from its own currents and mutual to refer to the field lines around one wire, from another conductor s currents. With this new perspective, the self inductance of a wire is the number of field lines from its own current, per amp of current. This will be independent of the presence of another conductor s current.
4 page - 4 of 10 If we bring a blue wire near the red wire, there will be a mutual inductance between them. This is the number of field lines that are around both wires, per amp of current in one of the wires. Figure 2 illustrates the field lines that compose self and mutual inductance. We measure mutual inductance in nh as well, since it is also a number of field lines per amp of current. Obviously, as we pull the wires apart, the mutual inductance between them will decrease. Figure 2 When a second wire carries a current, some of its field lines will completely surround the first wire. These magnetic field lines contribute to the mutual inductance between the conductors. Partial Inductance Of course, real currents flow in complete circuit loops. We have been looking at just a section of a wire. In this view, the only current that exists is the specific current in the section of wire we have drawn. When we have been counting field lines, we have ignored the field lines from the current in the rest of the circuit. This type of inductance is called the partial inductance of the wire, to distinguish the fact that we are looking at only a part of the loop. In reality, you can never have a partial current- you must always have current loops, but the concept of partial inductance is a very powerful tool to understand and calculate the other
5 page - 5 of 10 flavors of inductance, especially if you don't know what the rest of the loop looks like yet. Partial inductance has two flavors; partial self and partial mutual inductance. What we have been discussing above has really been the partial inductance of the blue and red wires. More often than not, when referring to the inductance of a lead in a package, or a connector pin, or a surface trace, we are really referring to the partial self inductance of this lead. As a rough rule of thumb, the partial self inductance of a round wire is about 25 nh/inch of length. So, a wire bond 100 mils long, has a partial self inductance of about 2.5 nh. A surface trace from a capacitor to a via, 50 mils long, has a partial self inductance of about 1.2 nh. A via through a board, 064 mils thick, has a partial self inductance of about 1.4 nh. For better approximations for partial self inductance and partial mutual inductance, see reference 1. In general, the mutual inductance between two wires is a small fraction of the self inductance of either one, and drops off very rapidly as the wires are pulled apart. For example, two wire bonds may each have a self inductance of 2.5 nh. If they are on a 5 mil pitch, they will have a mutual inductance of only 1 nh. This means that if there were 1A of current in one wire bond, there would be 1 nh x 1 Amp = 1 nanoweber of field lines around the second wire bond. As a rough rule of thumb, when the spacing is comparable to the length, the partial mutual inductance is down to 10% the self inductance. Two vias, 30 mils long, spaced on a 50 mil pitch, have virtually no mutual inductance between them and are completely independent. oop Inductance Suppose the red wire loops back on itself, as in Figure 3. The current in one leg produces field lines around the other one, but in the opposite direction. We can count the field lines around the entire loop by starting the count with the top half and adding all the field lines that are around the bottom half.
6 page - 6 of 10 (top) self M (bottom) self Figure 3. When both wire segments are part of the same loop, the current in the top segment is in the opposite direction as the current in the bottom segment. The field lines from the bottom segment, around the top segment will be in the opposite direction, and subtract from the field lines in the bottom segment. The total number of magnetic field lines around the top half are first due to its own current and self inductance, (top) Self x I, and the mutual inductance with the bottom half, m x I. However, the current is in the opposite direction on the bottom wire and thus, the field lines from the mutual inductance are in the opposite direction and subtract from the field lines from the self inductance. The total number of field lines around the top half of the loop is ((top) self m ) x I. ooking at the bottom wire, the field lines around it are due to its self inductance minus the mutual inductance, ((bottom) self m ) x I The total number of field lines around the complete loop, per amp of current in the loop is thus ((top) self + (bottom) self 2 m ). If the two halves of the loop are identical, and their self inductances are equal then the total loop inductance is the familiar: 2 self 2 m. If we know the partial self and mutual inductance's of each section of the loop, or any collection of conductors, we can calculate the loop inductance of any path. oop Inductance in Transmission ines When we look at signals propagating in a transmission line, the current, at the wavefront, is flowing though a loop composed of the partial self inductance of the signal path, and the partial self inductance of the return path. This is illustrated in Figure 3.
7 page - 7 of 10 signal Figure 4 The current at the leading edge of a signal is propagating in a loop that includes the signal path and the return path immediately beneath it. When the transmission line is balanced, as for example, twisted pair, or some types of coplanar lines, the partial self inductance of the two paths are equal. When the line is asymmetric, such as a microstrip, the partial self inductance of the two paths may be different. However, when we relate the inductance per length of the line and the capacitance per length of the line to get the characteristic impedance, as in: Z 0 = it is the loop inductance per length that we are using. As we saw above, the loop inductance is composed of the self and the mutual: oop = (signal) self + (return) self 2 m. In most applications, where all you worry about is the characteristic impedance, it s not important what the actual partial self and mutual inductances are. The only term that contributes to a measurable quantify is the loop inductance. However, in cases where the noise in the return path plays a role, as in the voltage created by common mode currents flowing in the plane that can contribute to EMI radiation, knowing the self inductance of the return path is important. The self inductance of the return path of stripline is less than in microstrip, which is why stripline offers better EM performance than a microstrip line.
8 page - 8 of 11 oop Mutual Inductance This loop inductance is really the self inductance of the loop, or the loop self inductance. You can see it coming: if there are two independent loops, there will be a mutual inductance between the two loops, which is the number of field lines from the current in one loop that completely surrounds the wire of the second loop. When current in one loop changes, it will change the number of field lines around the second loop and induce noise in the second loop. The amount of noise created is m I/ t. One of the coupling paths in two adjacent transmission lines is the mutual inductance between the current loops at the wavefront edge. The loops are composed of the signal paths and their return paths. When the return path is not a nice, uniform plane, the mutual inductance between two adjacent signal paths and their return can be large, as in the case of an I package, or a connector. This is the most common origin of what we usually call simultaneous switching output noise or SSO noise. The most important way of reducing it is reducing the mutual inductance between the loops. This can be by moving them farther way or decreasing the area of each loop, for example. When the return currents of two signal lines share the same conductor, the loop mutual inductance is dominated by the partial self inductance of the overlap region. This can be very large and is why you really want independent return path pins in a connector- a separate one for each signal path. Summary All the various flavors of inductance are directly related to the number of magnetic field lines around a conductor per amp of current. It s importance is in being able to predict the induced noise across a conductor when currents change. Just referring to an inductance can be ambiguous. We now see that to be clear, we need to specific the source of the currents, as in the self inductance or mutual inductance. And we need to specific whether we are referring to part of the circuit with partial inductance or the whole circuit with loop inductance. In addition, there is also effective and equivalent inductance, but that's another story. References 1. Bogatin, Eric, Beale, Bill and ight, David, Inductance Analysis of hip Scale Packages, Proceedings of SP Int l onf, San Jose, A, 1999, available for download from in the Oct 1999 downloads section.
9 page - 9 of Grover, F. W. Inductance alculations, 1973, Dover Publications. This is THE classic reference in inductance calculations. It is very technical and confusing, but is the source of many of the approximations offered for partial and loop inductance. 3. Walker,. S, apacitance, Inductance and rosstalk Analysis. 1990, Artech House. Many useful approximations for loop inductance and capacitance. 4. visit my web site has reviews and links to 20 recommended Signal Integrity textbooks, trade journals, conferences and web sites. Many articles and publications on signal integrity and interconnect design are also available for download.
10 page - 10 of 10 Bio of Dr. Eric Bogatin Eric Bogatin received his BS in Physics from MIT and his Masters and Ph.D., in Physics from the University of Arizona in Tucson. For the past 19 years, he has been actively involved in the field of signal integrity and interconnect design, working at companies such as AT&T Bell abs, Raychem orp, Sun Microsystems, and Ansoft orp. urrently, Eric is the principle instructor with Bogatin Enterprises, specializing in training classes for signal integrity and interconnect design. Bogatin Enterprises is devoted to accelerating engineers up the learning curve by providing an entire continuing education curriculum of signal integrity and interconnect design classes. Eric has trained over 2,000 engineers and lectures worldwide on signal integrity topics. Eric can be reached at Bogatin Enterprises, or check our web site
Dr. Eric Bogatin 26235 W 110 th Terr. Olathe, KS 66061 Voice: 913-393-1305 Fax: 913-393-1306 email@example.com www.bogatinenterprises.com Training for Signal Integrity and Interconnect Design Reprinted with
Page 1 of 9 The Critical Length of a Transmission Line Dr. Eric Bogatin President, Bogatin Enterprises Oct 1, 2004 Abstract A transmission line is always a transmission line. However, if it is physically
Slide #1 DIGITAL LOGIC CURRENT FLOW By Henry W. Ott Henry Ott Consultants www.hottconsultants.com firstname.lastname@example.org Slide #2 INTRODUCTION Many Engineers and Designers Are Confused About How And Where Digital
Connectivity in a Wireless World Cables Connectors 204 A Special Supplement to Signal Launch Methods for RF/Microwave PCBs John Coonrod Rogers Corp., Chandler, AZ COAX CABLE MICROSTRIP TRANSMISSION LINE
OOOO1 PCB Design Conference - East Keynote Address September 12, 2000 EMC ASPECTS OF FUTURE HIGH SPEED DIGITAL DESIGNS By Henry Ott Consultants Livingston, NJ 07039 (973) 992-1793 www.hottconsultants.com
In previous articles 1 I have pointed out that signals propagating down a trace reflect off the far end and travel back toward the source. These reflections can cause noise, and therefore signal integrity
Application Note: PCB Design By: Wei-Lung Ho Introduction: A printed circuit board (PCB) electrically connects circuit components by routing conductive traces to conductive pads designed for specific components
HB 11-26-07 Magnetic Field of a Circular Coil Lab 12 1 Magnetic Field of a Circular Coil Lab 12 Equipment- coil apparatus, BK Precision 2120B oscilloscope, Fluke multimeter, Wavetek FG3C function generator,
Electronic Components Induction In 1824, Oersted discovered that current passing though a coil created a magnetic field capable of shifting a compass needle. Seven years later, Faraday and Henry discovered
3.2.1. Circuit Modeling: Loop Impedance A loop antenna can be represented by a lumped circuit when its dimension is small with respect to a wavelength. In this representation, the circuit parameters (generally
1. A long, straight wire carries a current I. If the magnetic field at a distance d from the wire has magnitude B, what would be the the magnitude of the magnetic field at a distance d/3 from the wire,
260 17-1 I. THEORY EXPERIMENT 17 QUALITATIVE STUDY OF INDUCED EMF Along the extended central axis of a bar magnet, the magnetic field vector B r, on the side nearer the North pole, points away from this
E/M Experiment: Electrons in a Magnetic Field. PRE-LAB You will be doing this experiment before we cover the relevant material in class. But there are only two fundamental concepts that you need to understand.
Eatman Associates 2014 Rockwall TX 800-388-4036 rev. October 1, 2014 Striplines and Microstrips (PCB Transmission Lines) Disclaimer: This presentation is merely a compilation of information from public
The DC Motor Physics 1051 Laboratory #5 The DC Motor Contents Part I: Objective Part II: Introduction Magnetic Force Right Hand Rule Force on a Loop Magnetic Dipole Moment Torque Part II: Predictions Force
Time and Frequency Domain Analysis for Right Angle Corners on Printed Circuit Board Traces Mark I. Montrose Montrose Compliance Services 2353 Mission Glen Dr. Santa Clara, CA 95051-1214 Abstract: For years,
Chapter 22: Electric motors and electromagnetic induction The motor effect movement from electricity When a current is passed through a wire placed in a magnetic field a force is produced which acts on
How to make a Quick Turn PCB that modern RF parts will actually fit on! By: Steve Hageman www.analoghome.com I like to use those low cost, no frills or Bare Bones  type of PCB for prototyping as they
Chapter 19 Operational Amplifiers The operational amplifier, or op-amp, is a basic building block of modern electronics. Op-amps date back to the early days of vacuum tubes, but they only became common
INDUCTANCE MUTUAL INDUCTANCE If we consider two neighbouring closed loops and with bounding surfaces respectively then a current through will create a magnetic field which will link with as the flux passes
Lecture 24 Inductance and Switching Power Supplies (how your solar charger voltage converter works) Copyright 2014 by Mark Horowitz 1 Roadmap: How Does This Work? 2 Processor Board 3 More Detailed Roadmap
Motor Fundamentals Before we can examine the function of a drive, we must understand the basic operation of the motor. It is used to convert the electrical energy, supplied by the controller, to mechanical
AN18.6 SMSC Ethernet Physical Layer Layout Guidelines 1 Introduction 1.1 Audience 1.2 Overview SMSC Ethernet products are highly-integrated devices designed for 10 or 100 Mbps Ethernet systems. They are
White Paper: Virtex-II, Virtex-4, Virtex-5, and Spartan-3 FPGAs R WP323 (v1.0) March 28, 2008 Signal Integrity: Tips and Tricks By: Austin Lesea Signal integrity (SI) engineering has become a necessary
A METHOD OF CALIBRATING HELMHOLTZ COILS FOR THE MEASUREMENT OF PERMANENT MAGNETS Joseph J. Stupak Jr, Oersted Technology Tualatin, Oregon (reprinted from IMCSD 24th Annual Proceedings 1995) ABSTRACT The
Induced voltages and Inductance Faraday s Law concept #1, 4, 5, 8, 13 Problem # 1, 3, 4, 5, 6, 9, 10, 13, 15, 24, 23, 25, 31, 32a, 34, 37, 41, 43, 51, 61 Last chapter we saw that a current produces a magnetic
UTP Technology In the late 1970s, unshielded twisted pair (UTP) cabling originated in the computer industry as a means of transmitting digital data over computer networks. This cable was designed to be
Physics 221 Experiment 5: Magnetic Fields August 25, 2007 ntroduction This experiment will examine the properties of magnetic fields. Magnetic fields can be created in a variety of ways, and are also found
Linear DC Motors The purpose of this supplement is to present the basic material needed to understand the operation of simple DC motors. This is intended to be used as the reference material for the linear
Germanium Diode AM Radio LAB 3 3.1 Introduction In this laboratory exercise you will build a germanium diode based AM (Medium Wave) radio. Earliest radios used simple diode detector circuits. The diodes
1 " PCB Layout for Switching Regulators " 2 Introduction Linear series pass regulator I L V IN V OUT GAIN REF R L Series pass device drops the necessary voltage to maintain V OUT at it s programmed value
Inductors in AC Circuits Name Section Resistors, inductors, and capacitors all have the effect of modifying the size of the current in an AC circuit and the time at which the current reaches its maximum
Common Mode Choke Filtering Improves CMRR in Ethernet Transformer Applications June 2011 Application Note Common mode chokes provide an effective EMI filtering solution for Ethernet transformer applications.
Current Probes, More Useful Than You Think Training and design help in most areas of Electrical Engineering Copyright 1998 Institute of Electrical and Electronics Engineers. Reprinted from the IEEE 1998
Impedance Matching and Matching Networks Valentin Todorow, December, 2009 RF for Plasma Processing - Definition of RF What is RF? The IEEE Standard Dictionary of Electrical and Electronics Terms defines
Introduction to the Smith Chart for the MSA Sam Wetterlin 10/12/09 Quick Review of Reflection Coefficient The Smith chart is a method of graphing reflection coefficients and impedance, and is often useful
104 Practice Exam 2-3/21/02 1. Two electrons are located in a region of space where the magnetic field is zero. Electron A is at rest; and electron B is moving westward with a constant velocity. A non-zero
Module 3 AC Theory What you ll learn in Module 3. Section 3.1 Electromagnetic Induction. Magnetic Fields around Conductors. The Solenoid. Section 3.2 Inductance & Back e.m.f. The Unit of Inductance. Factors
Completed on 26th of June, 2012 MEASUREMENT SET-UP FOR TRAPS AUTHOR: IW2FND Attolini Lucio Via XXV Aprile, 52/B 26037 San Giovanni in Croce (CR) - Italy email@example.com Trappole_01_EN 1 1 DESCRIPTION...3
Nexus Technology Review -- Exhibit A Background A. Types of DSL Lines DSL comes in many flavors: ADSL, ADSL2, ADSL2+, VDSL and VDSL2. Each DSL variant respectively operates up a higher frequency level.
ElectroMagnetic Induction AP Physics B What is E/M Induction? Electromagnetic Induction is the process of using magnetic fields to produce voltage, and in a complete circuit, a current. Michael Faraday
IDT80HSPS1616 PCB Design Application Note - 557 Introduction This document is intended to assist users to design in IDT80HSPS1616 serial RapidIO switch. IDT80HSPS1616 based on S-RIO 2.0 spec offers 5Gbps
[ Assignment View ] [ Eðlisfræði 2, vor 2007 27. Magnetic Field and Magnetic Forces Assignment is due at 2:00am on Wednesday, February 28, 2007 Credit for problems submitted late will decrease to 0% after
Consideration of a high-capacity foil cable: Newly discovered ancient knowledge. The old RF-developers already knew the benefits of longplanar lines and have been used (electronic) Eonen (times) thin flat
Measuring Parasitic apacitance and Inductance Using TDR Time-domain reflectometry (TDR) is commonly used as a convenient method of determining the characteristic impedance of a transmission line or quantifying
Radiated Emission and Susceptibility Tzong-Lin Wu, Ph.D. EMC Lab Department of Electrical Engineering National Taiwan University Differential-Mode v.s. Common-mode Currents 1 Differential-Mode v.s. Common-mode
Contents 6.4 Normal Distribution....................... 381 6.4.1 Characteristics of the Normal Distribution....... 381 6.4.2 The Standardized Normal Distribution......... 385 6.4.3 Meaning of Areas under
Homework #11 203-1-1721 Physics 2 for Students of Mechanical Engineering 2. A circular coil has a 10.3 cm radius and consists of 34 closely wound turns of wire. An externally produced magnetic field of
CHAPTER 11: Flip Flops In this chapter, you will be building the part of the circuit that controls the command sequencing. The required circuit must operate the counter and the memory chip. When the teach
Guidelines for Designing High-Speed FPGA PCBs February 2004, ver. 1.1 Application Note Introduction Over the past five years, the development of true analog CMOS processes has led to the use of high-speed
The Simple DC Motor: A Teacher s Guide Kristy Beauvais Research Experience for Teachers Center for Materails Science and Engineering Massachusetts Institute of Technology August 2003 Motor Design: Steven
I Mapping the Magnetic Field Mapping the Magnetic Field Vector Fields The electric field, E, and the magnetic field, B, are two examples of what are termed vector fields, quantities which have both magnitude
Scott Hughes 7 April 2005 151 Using induction Massachusetts nstitute of Technology Department of Physics 8022 Spring 2005 Lecture 15: Mutual and Self nductance nduction is a fantastic way to create EMF;
12 Appendix 12 Earth Electrodes And Earth Electrode Testing 12.1 Introduction This appendix provides guidance and background information an earth electrode testing and some limited information on earth
2/20/2009 3 Transmission Lines and Waveguides.doc 1/3 Chapter 3 Transmission Lines and Waveguides First, some definitions: Transmission Line A two conductor structure that can support a TEM wave. Waveguide
COMPUTER AIDED ELECTRICAL DRAWING (CAED) EE Winding Diagrams: (i) DC Winding diagrams (ii) AC Winding Diagrams Terminologies used in winding diagrams: Conductor: An individual piece of wire placed in the
Application Report SLTA055 FEBRUARY 2006 Input and Output Capacitor Selection Jason Arrigo... PMP Plug-In Power ABSTRACT When designing with switching regulators, application requirements determine how
10. A ircuits* Objective: To learn how to analyze current and voltage relationships in alternating current (a.c.) circuits. You will use the method of phasors, or the vector addition of rotating vectors
PCB Design Guidelines for Dual Power Supply Voltage Translators Jim Lepkowski ON Semiconductor Introduction The design of the PCB is an important factor in maximizing the performance of a dual power supply
The Do s and Don ts of Pressure Transducers ABSTRACT When specifying a pressure transducer for a process measurement, a number of items have to be considered. Some of the more important ones are discussed
Direction of Induced Current Bar magnet moves through coil Current induced in coil A S N v Reverse pole Induced current changes sign B N S v v Coil moves past fixed bar magnet Current induced in coil as
1. The diagram below represents magnetic lines of force within a region of space. 4. In which diagram below is the magnetic flux density at point P greatest? (1) (3) (2) (4) The magnetic field is strongest
Worksheet BIOL 1107L Name Day/Time Refer to Chapter 5 and Chapter 16 (Figs. 16.5, 16.7, 16.8 and figure embedded in text on p. 310) in your textbook, Biology, 9th Ed, for information on and its structure
Reversing starter circuit for single phase induction motors Updated st September 008 Most single phase electric motors fitted to machine tools, compressors etc. are squirrel cage induction type which can
Designing VM2 Application Boards This document lists some things to consider when designing a custom application board for the VM2 embedded controller. It is intended to complement the VM2 Datasheet. A
SSF 14230 Road Vehicles - Diagnostic Systems Keyword Protocol 2000 - Part 1 - Physical Layer Swedish Implementation Standard Document: SSF 14230-1 Status: Issue 3 Date: October 22, 1997 This document is
[ Assignment View ] [ Print ] Eðlisfræði 2, vor 2007 30. Inductance Assignment is due at 2:00am on Wednesday, March 14, 2007 Credit for problems submitted late will decrease to 0% after the deadline has
Windshield Wiper Motors Originally posted by Dan Masters, firstname.lastname@example.org Also see http://www.advanceautowire.com/ WIPER OPERATION: There are three major components to a wiper motor: Motor Rotary to linear
Control Engineering Prof. Madan Gopal Department of Electrical Engineering Indian Institute of Technology, Delhi Lecture - 11 Models of Industrial Control Devices and Systems (Contd.) Last time we were
Charged cable event David Pommerenke, email@example.com, 916 785 4550 Last update: Feb.23, 2001 Content Goal Energy sources, which may lead to CDE. Complexity of the different discharge modes. Possible
DIRECT CURRENT GENERATORS Revision 12:50 14 Nov 05 INTRODUCTION A generator is a machine that converts mechanical energy into electrical energy by using the principle of magnetic induction. This principle
Voltage, Current, Resistance, Capacitance and Inductance Really basic electrical engineering. 1 Electricity and conductors Electricity is the movement of electrons. Electrons move easily through a conductor
PHY115 Experiment 11 Build A Simple Electric Motor (example #1) MATERIAL This is the necessary equipment. Present any list of material in your written lab report. 1.5 V battery in series 1 ceramic magnet
Time allowed: 3 hours The 2010 British Informatics Olympiad Instructions You should write a program for part (a) of each question, and produce written answers to the remaining parts. Programs may be used
Revised 7/2/08 Balanced vs. Unbalanced Audio Interconnections In discussing the characteristics and performance of various interconnect systems; two points should be kept in mind. Balance is defined in
Oscar E. Morel UtilX Corporation Time Domain Reflectometry (TDR) has been the preferred technique to assess: Cable length Splice number and spatial location, and Metallic neutral condition Tests for neutral
Application Note AN-1135 PCB Layout with IR Class D Audio Gate Drivers By Jun Honda, Connie Huang Table of Contents Page Application Note AN-1135... 1 0. Introduction... 2 0-1. PCB and Class D Audio Performance...
Customers are required to follow certain criteria for all designs whether they are ultimately done in EECAD or by the customers themselves. These criteria, approved by EES Management, are listed below:
Chunking? Sounds like psychobabble! By Sarah Frossell Published in Rapport Magazine Winter 1998 So much of the business world depends on the fast, free flow of information but does the unit size the information
Extra Questions - 2 1. A straight length of wire moves through a uniform magnetic field. The e.m.f. produced across the ends of the wire will be maximum if it moves: a) along the lines of magnetic flux