DOCSLIB.ORG

Direct-Current Circuits

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Direct-Current Circuits Direct-Current Circuits Physics 231 Lecture 6-1 Fall 2008 Resistors in Series and Parallel As with capacitors, resistors are often in series and parallel configurations in circuits Series Parallel The question then is what is the equivalent resistance Physics 231 Lecture 6-2 Fall 2008 Resistors in Series Since these resistors are in series, we have the same current in all three resistors I1 = I2 = I3 = I We also have that the sum of the potential differences across the three resistors must be the same as the potential difference between points a and b Vab =Vax +Vxy +Vyb Physics 231 Lecture 6-3 Fall 2008 Resistors in Series Then using Vax = I R1; Vxy = I R2; Vyb = I R3 We have that Vab = I (R1 + R2 + R3 ) Now the equivalent resistor, R, will also have the same potential difference across it as Vab, and it will also have the same current I Vab = I R Equating these last two results, we then have that R = R1 + R2 + R3 = ∑ Ri i The equivalent resistance for a sequence of resistors in series is just the sum of the individual resistances Physics 231 Lecture 6-4 Fall 2008 Resistors in Parallel Here we have that the voltage across each resistor has to be the same (work done in going from a to b is independent of the path, independent of which resistor you go through) V1 =V2 =V3 =Vab Physics 231 Lecture 6-5 Fall 2008 Resistors in Parallel We now deal with currents through the resistors At point a the current splits up into three distinct currents We have that the sum of theses three currents must add to the value coming into this point I = I1 + I2 + I3 Vab Vab Vab We also have that I1 = ; I2 = ; I3 = R1 R2 R3 The equivalent resistor, R, will have also have the current I going through it Physics 231 Lecture 6-6 Fall 2008 Resistors in Parallel V Using I = ab R and combining with the previous equations, we then have V V V V ab = ab + ab + ab R R1 R2 R3 or 1 1 1 1 1 = + + = ∑ R R1 R2 R3 i Ri The inverse of the effective resistance is given by the sum of the inverses of the individual resistances Physics 231 Lecture 6-7 Fall 2008 Solving Resistor Networks Make a drawing of the resistor network Determine whether the resistors are in series or parallel or some combination Determine what is being asked Equivalent resistance Potential difference across a particular resistance Current through a particular resistor Physics 231 Lecture 6-8 Fall 2008 Solving Resistor Networks Solve simplest parts of the network first Then redraw network using the just calculated effective resistance Repeat calculating effective resistances until only one effective resistance is left Physics 231 Lecture 6-9 Fall 2008 Solving Resistor Networks Given the following circuit What is the equivalent resistance and what is the current through each resistor We see that we have two resistors in parallel with each other and the effective resistance of these two is in series with the remaining resistor Physics 231 Lecture 6-10 Fall 2008 Solving Resistor Networks Step 1: Combine the two resistors that are in parallel 1 1 1 1 = + = ; Reff = 2 Ω Reff 6 Ω 3 Ω 2 Ω yielding Step 2: Combine the two resistors that are in series Reff = 4 Ω + 2 Ω = 6 Ω yielding Physics 231 Lecture 6-11 Fall 2008 Solving Resistor Networks Current through this effective resistor is given by V 18 I = = = 3 Amps Reff 6 The current through the resistors in the intermediate circuit of Step 1 is also 3 Amps with the voltage drop across the individual resistors being given by V4Ω = 3⋅ 4 =12Volts; V2Ω = 3⋅ 2 = 6Volts Physics 231 Lecture 6-12 Fall 2008 Solving Resistor Networks To find the current through the resistors of the parallel section of the initial circuit, we use the fact that both resistors have the same voltage drop – 6 Volts 6Volts I = =1Amp; 6Ω 6Ω 6Volts I = = 2 Amps 3Ω 3Ω Physics 231 Lecture 6-13 Fall 2008 Consistency Check There is a check that can be made to see if the answers for the currents make sense: The power supplied by the battery should equal the total power being dissipated by the resistors The power being supplied by the battery is given by P = IV where I is the total current P = IV = 3⋅18 = 54Watts The power being dissipated by each of the resistors is given by P = I 2 R 2 2 P4Ω = 3 ⋅ 4 = 36Watts; P3Ω = 2 ⋅3 =12Watts; 2 P6Ω =1 ⋅ 6 = 6Watts; PTotal = 54Watts Physics 231 Lecture 6-14 Fall 2008 Example 1 Two identical light bulbs are represented by the resistors R2 and R3 (R2 = R3 ). The switch S is initially open. If switch S is closed, what happens to the brightness of the bulb R2? a) It increases b) It decreases c) It doesn’t change 2 The power dissipated in R2 is given by P =V R When the switch is closed neither V nor R changes So the brightness does not change Physics 231 Lecture 6-15 Fall 2008 Example 2 Two identical light bulbs are represented by the resistors R2 and R3 (R2 = R3 ). The switch S is initially open. What happens to the current I, after the switch is closed ? a) Iafter = 1/2 Ibefore b) Iafter = Ibefore c) Iafter = 2 Ibefore Initially the current is given by Ibefore = ε R2 After the switch is closed the net resistance is given by 1 1 1 2 R = + = since R = R R = 2 2 3 net 2 Rnet R2 R3 R2 ε ⎛ ε ⎞ The new current is then Iafter = = 2⎜ ⎟ = 2Ibefore Rnet ⎝ R2 ⎠ Physics 231 Lecture 6-16 Fall 2008 Kirchoff’s Rules Not all circuits are reducible There is no way to reduce the four resistors to one effective resistance or to combine the three voltage sources to one voltage source Physics 231 Lecture 6-17 Fall 2008 Kirchoff’s Rules First some terminology A junction, also called a node or branch point, is is a point where three or more conductors meet A loop is any closed conducting path Physics 231 Lecture 6-18 Fall 2008 Kirchoff’s Rules Kirchoff’s Rules are basically two statements 1. The algebraic sum of the I = 0 currents into any junction is zero ∑ A sign convention: A current heading towards a junction, is considered to be positive, A current heading away from a junction, is considered to be negative I1 + I2 − I3 = 0 Be aware that all the junction equations for a circuit may not be independent of each other Physics 231 Lecture 6-19 Fall 2008 Kirchoff’s Rules 2. The algebraic sum of the potential differences in any loop including those associated with emfs and those of resistive elements must equal zero ∑V = 0 Procedures to apply this rule: Pick a direction for the current in each branch If you picked the wrong direction, the current will come out negative Physics 231 Lecture 6-20 Fall 2008 Kirchoff’s Rules Pick a direction for traversing a loop – this direction must be the same for all loops Note that there is a third loop along the outside branches As with the junction equations not all the loop equations will be independent of each other. Physics 231 Lecture 6-21 Fall 2008 Kirchoff’s Rules Starting at any point on the loop add the emfs and IR terms An IR term is negative if we traverse it in the same sense as the current that is going through it, otherwise it is positive An emf is considered to be positive if we go in the direction - to +, otherwise it is negative Need to have as many independent equations as there are unknowns Physics 231 Lecture 6-22 Fall 2008 Kirchoff’s Rules For loop I we have − I1R1 − I1R2 − I3R4 + ε1 − ε3 = 0 For loop II we have − I2R3 + I3R4 − ε 2 + ε3 = 0 Junction equation at a gives us I1 − I2 − I3 = 0 We now have three equations for the three unknown currents Physics 231 Lecture 6-23 Fall 2008 Kirchoff’s Rules Assume that the batteries are: ε1 = 19 V; ε2 = 6 V; ε3 = 2 V and the resistors are: R1 = 6Ω; R2 = 4Ω; R3 = 4Ω; R4 = 1Ω you should end up with: I1 = 1.5 A; I2 = -0.5 A; I3 = 2.0 A The minus sign on I2 indicates that the current is in fact in the opposite direction to that shown on the diagram Complete details can be found here Physics 231 Lecture 6-24 Fall 2008 RC Circuits Up until now we have assumed that the emfs and resistances are constant in time so that all potentials, currents, and powers are constant in time However, whenever we have a capacitor that is being charged or discharged this is not the case Now consider a circuit that consists of a source of emf, a resistor and a capacitor but with an open switch With the switch open the current in the circuit is zero and zero charge accumulates on the capacitor Physics 231 Lecture 6-25 Fall 2008 RC Circuits Now close the switch Initially the full potential will be across the resistor as the potential across the capacitor is zero since q is zero Initially the full potential is across the resistor The initial current in the circuit is then given by I0 = ε / R As the current flows a charge will accumulate on the capacitor At some time t, the current in the circuit will be I and the charge on the capacitor will be q Physics 231 Lecture 6-26 Fall 2008 RC Circuits According to Kirchoff’s 2nd rule we have Using a counterclockwise loop ε −Vresistor −Vcapacitor = 0 q ε − IR − = 0 C ε q Solving for the current I = − R RC As time increases, the charge on the capacitor increases, therefore the current in the circuit decreases Current will flow until the capacitor has a charge on it given by Q = C ε Physics 231 Lecture 6-27 Fall 2008 RC Circuits d q We remember that I = d t dq ε q 1 So we then have = − = − ()q − Cε dt R RC RC d q d t Rearranging we have = − q − Cε RC q d q t d t Setting up the integration we have = − ∫ q − Cε ∫ RC 0 0 ⎛ q − Cε ⎞ 1 The resultant integration yields ln⎜ ⎟ = − ⎝ − Cε ⎠ RC Physics 231 Lecture 6-28 Fall 2008 RC Circuits We exponentiate both sides of this last equation and rearrange to obtain −t / RC −t / RC q = Cε (1− e )= Q f (1− e ) where Qf is the final charge on the capacitor given by Cε The constant RC is known as the time constant of the circuit We see that the charge on the capacitor increases exponentially Physics 231 Lecture 6-29 Fall 2008 Example 3 I1 At t = 0 the switch is closed in I2 I3 the circuit shown.
Load more

Recommended publications
  • Introduction to Direct Current (DC) Theory
    PDHonline Course E235 (4 PDH) Electrical Fundamentals - Introduction to Direct Current (DC) Theory Instructor: A. Bhatia, B.E. 2012 PDH Online | PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030-6658 Phone & Fax: 703-988-0088 www.PDHonline.org www.PDHcenter.com An Approved Continuing Education Provider CHAPTER 3 DIRECT CURRENT LEARNING OBJECTIVES Upon completing this chapter, you will be able to: 1. Identify the term schematic diagram and identify the components in a circuit from a simple schematic diagram. 2. State the equation for Ohm's law and describe the effects on current caused by changes in a circuit. 3. Given simple graphs of current versus power and voltage versus power, determine the value of circuit power for a given current and voltage. 4. Identify the term power, and state three formulas for computing power. 5. Compute circuit and component power in series, parallel, and combination circuits. 6. Compute the efficiency of an electrical device. 7. Solve for unknown quantities of resistance, current, and voltage in a series circuit. 8. Describe how voltage polarities are assigned to the voltage drops across resistors when Kirchhoff's voltage law is used. 9. State the voltage at the reference point in a circuit. 10. Define open and short circuits and describe their effects on a circuit. 11. State the meaning of the term source resistance and describe its effect on a circuit. 12. Describe in terms of circuit values the circuit condition needed for maximum power transfer. 13. Compute efficiency of power transfer in a circuit. 14. Solve for unknown quantities of resistance, current, and voltage in a parallel circuit.
    [Show full text]
  • A Dc–Dc Converter with High-Voltage Step-Up Ratio and Reduced- Voltage Stress for Renewable Energy Generation Systems
    A DC–DC CONVERTER WITH HIGH-VOLTAGE STEP-UP RATIO AND REDUCED- VOLTAGE STRESS FOR RENEWABLE ENERGY GENERATION SYSTEMS A Dissertation by Satya Veera Pavan Kumar Maddukuri Master of Science, University of Greenwich, UK, 2012 Bachelor of Technology, Jawaharlal Nehru Technology University Kakinada, India, 2010 Submitted to the Department of Electrical Engineering and Computer Science and the faculty of the Graduate School of Wichita State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2018 1 © Copyright 2018 by Satya Veera Pavan Kumar Maddukuri All Rights Reserved 1 A DC–DC CONVERTER WITH HIGH-VOLTAGE STEP-UP RATIO AND REDUCED- VOLTAGE STRESS FOR RENEWABLE ENERGY GENERATION SYSTEMS The following faculty members have examined the final copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirement for the degree of Doctor of Philosophy with a major in Electrical Engineering and Computer Science. ___________________________________ Aravinthan Visvakumar, Committee Chair ___________________________________ M. Edwin Sawan, Committee Member ___________________________________ Ward T. Jewell, Committee Member ___________________________________ Chengzong Pang, Committee Member ___________________________________ Thomas K. Delillo, Committee Member Accepted for the College of Engineering ___________________________________ Steven Skinner, Interim Dean Accepted for the Graduate School ___________________________________ Dennis Livesay, Dean iii DEDICATION To my parents, my wife, my in-laws, my teachers, and my dear friends iv ACKNOWLEDGMENTS Firstly, I would like to express my sincere gratitude to my advisor Dr. Aravinthan Visvakumar for the continuous support of my PhD study and related research, for his thoughtful patience, motivation, and immense knowledge. His guidance helped me in all the time of research and writing of this dissertation.
    [Show full text]
  • Instructor's Guide
    Instructor’s Guide Electricity: A 3-D Animated Demonstration ELECTRICITY AND MAGNETISM Introduction This instructor’s guide provides information to help you get the most out of Electricity and Magnetism, part of the eight-part series Electricity: A 3-D Animated Demonstration. The series makes the principles of electricity easier to understand and discuss. The series includes Electrostatics; Electric Current; Ohm's Law; Circuits; Power and Efficiency; Electricity and Magnetism; Electric Motors; and Electric Generators. Electricity and Magnetism traces the relationship between magnetism and electricity from the first accidental discovery of induced current. Learning Objectives After watching the video program, students will be able to: • Describe the relationship between electricity and magnetism • Explain the difference between electric and magnetic fields • Explain the construct, function, and use of solenoids • Differentiate between, explain, and apply the left-hand and right-hand rules • Demonstrate (via experiments) and explain aspects, and actions and functions of electricity, magnetism, and electromagnetism Educational Standards National Science Standards This program correlates with the National Science Education Standards from the National Academies of Science, and Project 2061, from the American Association for the Advancement of Science. Copyright © 2008 SHOPWARE® • www.shopware-usa.com • 1-800-487-3392 Electricity: A 3-D Animated Demonstration ELECTRICITY AND MAGNETISM INSTRUCTOR’S GUIDE Science as Inquiry Content Standard A:
    [Show full text]
  • Faraday's Law Da
    Faraday's Law dA B B r r Φ≡B •d A B ∫ dΦ ε= − B dt Faraday’s Law of Induction r r Recall the definition of magnetic flux is ΦB =B∫ ⋅ d A Faraday’s Law is the induced EMF in a closed loop equal the negative of the time derivative of magnetic flux change in the loop, d r r dΦ ε= −B∫ d ⋅= A − B dt dt Constant B field, changing B field, no induced EMF causes induced EMF in loop in loop Getting the sign EMF in Faraday’s Law of Induction Define the loop and an area vector, A, who magnitude is the Area and whose direction normal to the surface. A The choice of vector A direction defines the direction of EMF with a right hand rule. Your thumb in A direction and then your fingers point to positive EMF direction. Lenz’s Law – easier way! The direction of any magnetic induction effect is such as to oppose the cause of the effect. ⇒ Convenient method to determine I direction Heinrich Friedrich Example if an external magnetic field on a loop Emil Lenz is increasing, the induced current creates a field opposite that reduces the net field. (1804-1865) Example if an external magnetic field on a loop is decreasing, the induced current creates a field parallel to the that tends to increase the net field. Incredible shrinking loop: a circular loop of wire with a magnetic flux is shrinking with time. In which direction is the induced current? (a) There is none. (b) CW.
    [Show full text]
  • Teaching H. C. Ørsted's Scientific Work in Danish High School Physics
    UNIVERSITY OF COPENHAGEN FACULTY OF SCIENCE Ida Marie Monberg Hindsholm Teaching H. C. Ørsted's Scientific Work in Danish High School Physics Masterʹs thesis Department of Science Education 19 July 2018 Master's thesis Teaching H. C. Ørsted’s Scientific Work in Danish High School Physics Submitted 19 July 2018 Author Ida Marie Monberg Hindsholm, B.Sc. E-mail [email protected] Departments Niels Bohr Institute, University of Copenhagen Department of Science Education, University of Copenhagen Main supervisor Ricardo Avelar Sotomaior Karam, Associate Professor, Department of Science Education, University of Copenhagen Co-supervisor Steen Harle Hansen, Associate Professor, Niels Bohr Institute, University of Copenhagen 1 Contents 1 Introduction . 1 2 The Material: H. C. Ørsted's Work . 3 2.1 The Life of Hans Christian Ørsted . 3 2.2 Ørsted’s Metaphysical Framework: The Dynamical Sys- tem............................. 6 2.3 Ritter and the failure in Paris . 9 2.4 Ørsted’s work with acoustic and electric figures . 12 2.5 The discovery of electromagnetism . 16 2.6 What I Use for the Teaching Sequence . 19 3 Didactic Theory . 20 3.1 Constructivist teaching . 20 3.2 Inquiry Teaching . 22 3.3 HIPST . 24 4 The Purpose and Design of the Teaching Sequence . 27 4.1 Factual details and lesson plan . 28 5 Analysis of Transcripts and Writings . 40 5.1 Method of Analysis . 40 5.2 Practical Problems . 41 5.3 Reading Original Ørsted's Texts . 42 5.4 Inquiry and Experiments . 43 5.5 "Role play" - Thinking like Ørsted . 48 5.6 The Reflection Corner . 51 5.7 Evaluation: The Learning Objectives .
    [Show full text]
  • AC Vs. DC Boost Converters: a Detailed Conduction Loss Comparison
    AC vs. DC Boost Converters: A Detailed Conduction Loss Comparison Daniel L Gerber Fariborz Musavi Building Technology and Urban Systems Engineering and Computer Science Lawrence Berkeley Labs Washington State University Berkeley, CA, USA Vancouver, WA, USA [email protected] [email protected] Abstract—Studies have shown the efficiency benefits of DC dis- at the same voltage. Although several previous works have tribution systems are largely due to the superior performance of analyzed and established loss models for the DC/DC [9]– DC/DC converters. Nonetheless, these studies are often based on [12] and AC/DC PFC [13]–[20] boost converters, they each product data that differs widely in manufacturer and operating have their own methods and formulae, making an analytic voltage. This work develops a rigorous loss model to theoretically comparison difficult. In addition, many of them neglect es- compare the efficiency of a DC/DC and an AC/DC PFC boost sential components such as the input bridge drop and output converter. It ensures each converter has the same components and equivalent operating voltages. The results show AC boost capacitor equivalent series resistance (ESR). This is the first converters below 500 W to have 2.9 to 4.2 times the loss of DC. work to establish a set of formulae that compare the loss between an AC and DC boost converter, both of which have the Keywords—DC microgrid, boost converter, loss model, power same components and equivalent operating voltages. Although factor correction DC/DC converters are already known to be more efficient, this work reports exactly how much more.
    [Show full text]
  • Faraday's Law Da
    Faraday's Law dA B B r r Φ≡B •d A B ∫ dΦ ε= − B dt Applications of Magnetic Induction • AC Generator – Water turns wheel Æ rotates magnet Æ changes flux Æ induces emf Æ drives current • “Dynamic” Microphones (E.g., some telephones) – Sound Æ oscillating pressure waves Æ oscillating [diaphragm + coil] Æ oscillating magnetic flux Æ oscillating induced emf Æ oscillating current in wire Question: Do dynamic microphones need a battery? More Applications of Magnetic Induction • Tape / Hard Drive / ZIP Readout – Tiny coil responds to change in flux as the magnetic domains (encoding 0’s or 1’s) go by. 2007 Nobel Prize!!!!!!!! Giant Magnetoresistance • Credit Card Reader – Must swipe card Æ generates changing flux – Faster swipe Æ bigger signal More Applications of Magnetic Induction • Magnetic Levitation (Maglev) Trains – Induced surface (“eddy”) currents produce field in opposite direction Æ Repels magnet Æ Levitates train S N rails “eddy” current – Maglev trains today can travel up to 310 mph Æ Twice the speed of Amtrak’s fastest conventional train! – May eventually use superconducting loops to produce B-field Æ No power dissipation in resistance of wires! Faraday’s Law of Induction r r Recall the definition of magnetic flux is ΦB =B∫ ⋅ d A Faraday’s Law is the induced EMF in a closed loop equal the negative of the time derivative of magnetic flux change in the loop, d r r dΦ ε= −B∫ d ⋅= A − B dt dt Constant B field, changing B field, no induced EMF causes induced EMF in loop in loop Getting the sign EMF in Faraday’s Law of Induction Define the loop and an area vector, A, who magnitude is the Area and whose direction normal to the surface.
    [Show full text]
  • DIRECT CURRENT CIRCUITS I [Written by Suzanne Amador Kane; Modified Slightly for Our Purposes.] Readings: Serway, Chapters 27–28
    DIRECT CURRENT CIRCUITS I [Written by Suzanne Amador Kane; Modified slightly for our purposes.] Readings: Serway, Chapters 27–28. At long last we are ready to begin work with Direct Current (DC) Circuits. DC circuits are those in which the voltages and currents are constant, or time-independent. Time-dependent circuits in which the current oscillates periodically are referred to as Alternating Current (AC) circuits. We will study AC circuits soon enough. As you know, charge is the fundamental unit of electricity much as mass is the fundamental unit of gravitation. A significant difference is that mass is always positive (as far as we know), while charge can be either positive or negative. When charges flow, they form a current, just as when mass moves it has momentum. If we drop a mass, it "flows" down to a lower potential, and a potential difference in an electric circuit drives a current to the lower potential from the higher potential. Since charges come in both positive and negative flavors, electrical potential drives some charges up while others flow down. By analogy, if there were negative mass, it would fall up. When a ball is dropped into a liquid, it falls more slowly due to the resistance of the liquid. Likewise, in a circuit we insert a "resistor" which impedes the flow of current. In a circuit, the effect is to lower the rate at which charge moves, effectively lowering the current which flows through the circuit. It is useful to note here that if we did not have a resistor, in effect it would be like dropping a huge object onto the Earth without air resistance – look at the craters on the Moon to see how undesirable this would be! In circuits, this is called a "short circuit" and it quickly drains the potential while also risking serious damage to the components (and the experimenter).
    [Show full text]
  • DC Power Production, Delivery and Utilization
    DDCC PPowerower PProduction,roduction, DDeliveryelivery aandnd UUtilizationtilization An EPRI White Paper June 2006 AAnn EEPRIPRI WWhitehite PPaperaper DC Power Production, Delivery and Utilization This paper was prepared by Karen George of EPRI Solutions, Inc., based on technical material from: Arshad Mansoor, Vice President, EPRI Solutions Clark Gellings, Vice President—Innovation, EPRI Dan Rastler, Tech Leader, Distributed Resources, EPRI Don Von Dollen, Program Director, IntelliGrid, EPRI AAcknowledgementscknowledgements We would like to thank reviewers and contributors: Phil Barker, Principal Engineer, Nova Energy Specialists David Geary, Vice President, of Engineering, Baldwin Technologies, Inc. Haresh Kamath, EPRI Solutions Tom Key, Principal Technical Manager, EPRI Annabelle Pratt, Power Architect, Intel Corporation Mark Robinson, Vice President, Nextek Power Copyright ©2006 Electric Power Research Institute (EPRI), Palo Alto, CA USA June 2006 Page 2 AAnn EEPRIPRI WWhitehite PPaperaper DC Power Production, Delivery and Utilization Edison Redux: The New AC/DC Debate Thomas Edison’s nineteenth-century electric distribution sys- Several converging factors have spurred the recent interest in tem relied on direct current (DC) power generation, delivery, DC power delivery. One of the most important is that an in- and use. This pioneering system, however, turned out to be im- creasing number of microprocessor-based electronic devices practical and uneconomical, largely because in the 19th cen- use DC power internally, converted inside the device from tury, DC power generation was limited to a relatively low volt- standard AC supply. Another factor is that new distributed re- age potential and DC power could not be transmitted beyond sources such as solar photovoltaic (PV) arrays and fuel cells a mile.
    [Show full text]
  • Electromagnetic Coil Gun – Design and Construction
    Bohumil SKALA Vladimir KINDL ELECTROMAGNETIC COIL GUN – DESIGN AND CONSTRUCTION ABSTRACT A single-stage, sensor less, coil gun was designed to demonstrate the capability to accelerate a ferromagnetic projectile to high velocity. This paper summarize all important steps during coil gun design, such as physical laws of the coil gun, preliminary calculations, the testing device and final product. The electromagnetic FEA model of the capacitor-driven inductance coil gun was constructed to be able to optimize the coil's dimensions. The driving circuit was implemented as dynamic model for simulation of current. The coil gun is designed for an exhibition centre as an exhibit. It is not designed for a really shooting applications, this means the projectile is accelerated at relatively low speed. Keywords: Coil gun, electronics, FEM, electromagnetic force 1. INTRODUCTION Electromagnetic accelerating systems are usually constructed as rail guns [3] or coil guns [1]. The rail gun is conceptually more simple than the coil gun, but has some inherent problems with plasma [2] during the projectile launches. That is why this conception is not use here. On the other hand the coil gun is much more suitable for common applications even if it needs some additional supporting facilities [4] such as energy accumulator, switcher and driver. Its main advantage lies in loose of almost all negative phenomena damaging the launch device. Doc. Ing. Bohumil SKALA, Ph.D. e-mail: [email protected] Ing. Vladimir KINDL, Ph.D. e-mail: [email protected] Dept. of Electromechanics and Power Electronics, University of West Bohemia in Pilsen, Univerzitní 8, 306 14 Pilsen, CZ PROCEEDINGS OF ELECTROTECHNICAL INSTITUTE, Issue 263, 2013 116 B.
    [Show full text]
  • Electromagnetic Coil Gun Launcher System
    ISSN(Online): 2319-8753 ISSN (Print) : 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (A High Impact Factor, Monthly, Peer Reviewed Journal) Visit: www.ijirset.com Vol. 8, Issue 3, March 2019 Electromagnetic Coil Gun Launcher System Prof. Yogesh Fatangde1 Swapnil Biradar2, Aniket Bahmne3, Suraj Yadav4, Ajay Yadav5 Department of Mechanical Engineering, RMD Sinhgad Technical Campus, Savitribai Phule Pune University, Pune, Maharashtra, India1 ABSTRACT: In our present time, a study was undertaken to determine if ground based electromagnetic acceleration system could provide a useful reduction in launching cost with current large chemical boosters, while increasing launch safety and reliability. An electromagnetic launcher (EML) system accelerates and launches a projectile by converting electric energy into kinetic energy. An EML system launches projectile by converting electric energy into kinetic energy. There are two types of EML system under development: rail gun and coil gun. A coil gun launches the projectile by magnetic force of electromagnetic coil. A higher velocity needs multiple stages of system, which make coil gun EML system longer. As a result installation cost is very high and it required large installation site for EML. So, we present coil gun EML system with new structure and arrangement for multiple electromagnetic coils to reduce the length of system KEYWORDS: EML, coil gun, Electromagnetic launcher, suck back effect I. INTRODUCTION In chemical launcher systems such as firearms and satellite launchers, chemical explosive energy is converted into mechanical dynamic energy. The system must be redesigned and remanufactured if the target velocity of the projectile is changed. In addition, such systems are not eco-friendly.
    [Show full text]
  • Chapter 21 Electric Current and Direct-Current Circuits
    Chapter 21 Electric Current and Direct-Current Circuits 21.1 Electric Current 21.2 Resistance and Ohm’s Law 21.3 Energy and Power in Electric Circuits 21.4 Resisters in Series and Parallel 21.5 Circuits Containing Capacitors Chapter 21 What is electricity? What is electric current? Why does it flow when we flick a switch? Why do bulbs glow when current is supplied. Why do the wires not glow? A battery Figure 21–1 Water flow as analogy for electric current Water can flow quite freely through a garden hose, but if both ends are at the same level (a) there is no flow. If the ends are held at different levels (b), the water flows from the region where the gravitational potential energy is high to the region where it is low. Figure 21–2 The flashlight: A simple electrical circuit (a) A simple flashlight, consisting of a battery, a switch, and a light bulb. (b) When the switch is in the open position the circuit is “broken,” and no charge can flow. When the switch is closed electrons flow through the circuit, and the light glows. Figure 21–3 A mechanical analog to the flashlight circuit The person lifting the water corresponds to the battery in Figure 21–2, and the paddle wheel corresponds to the light bulb. Electromotive force (emf) ∆qV=qEd + - + - + - Think of a battery as a pair of plates that are continually charged up. For a charge to go from one plate to the other it will give up energy = ∆qV. Figure 21–4 Direction of current and electron flow In the flashlight circuit, electrons flow from the negative terminal of the battery to the positive terminal.
    [Show full text]