Magnetic actuators and sensors

✍ Scribed by John R Brauer

• Publisher: John Wiley and Sons
• Tongue: English
• Leaves: 397
• Category: Library

✦ Synopsis

"An accessible, comprehensive guide on magnetic actuators and sensors, this fully updated second edition of Magnetic Actuators and Sensors includes the latest advances, numerous worked calculations, illustrations, and real-life applications. Covering magnetics, actuators, sensors, and systems, with updates of new technologies and techniques, this exemplary learning tool emphasizes computer-aided design techniques, especially magnetic finite element analysis, commonly used by today's engineers. Detailed calculations, numerous illustrations, and discussions of discrepancies make this text an invaluable learning tool for practicing engineers and engineering students"--

"Like the first edition, this book will be for practicing engineers and engineering students involved with the design and application of magnetic actuators and sensors"-- Read more...

✦ Table of Contents

Content: PREFACE xi PREFACE TO THE FIRST EDITION xiii LIST OF 66 EXAMPLES xv PART I MAGNETICS 1 1 Introduction 3 1.1 Overview of Magnetic Actuators 3 1.2 Overview of Magnetic Sensors 4 1.3 Actuators and Sensors in Motion Control Systems 5 1.4 Magnetic Actuators and Sensors in Mechatronics 7 References 8 2 Basic Electromagnetics 9 2.1 Vectors 9 2.2 Ampere's Law 14 2.3 Magnetic Materials 17 2.4 Faraday's Law 22 2.5 Potentials 25 2.6 Maxwell's Equations 28 Problems 29 References 31 3 Reluctance Method 33 3.1 Simplifying Ampere's Law 33 3.2 Applications 37 3.3 Fringing Flux 40 3.4 Complex Reluctance 41 3.5 Limitations 41 Problems 42 References 42 4 Finite-Element Method 43 4.1 Energy Conservation and Functional Minimization 43 4.2 Triangular Elements for Magnetostatics 45 4.3 Matrix Equation 46 4.4 Finite-Element Models 49 Problems 53 References 53 5 Magnetic Force 55 5.1 Magnetic Flux Line Plots 55 5.2 Magnetic Energy 60 5.3 Magnetic Force on Steel 61 5.4 Magnetic Pressure on Steel 65 5.5 Lorentz Force 66 5.6 Permanent Magnets 67 5.7 Magnetic Torque 72 5.8 Magnetic Volume Forces on Permeable Particles 73 Problems 75 References 76 6 Other Magnetic Performance Parameters 79 6.1 Magnetic Flux and Flux Linkage 79 6.2 Inductance 82 6.3 Capacitance 86 6.4 Impedance 88 Problems 91 References 91 PART II ACTUATORS 93 7 Magnetic Actuators Operated by DC 95 7.1 Solenoid Actuators 95 7.2 Voice Coil Actuators 106 7.3 Other Actuators Using Coils and Permanent Magnets 108 7.4 Proportional Actuators 109 7.5 Rotary Actuators 112 7.6 Magnetic Bearings and Couplings 114 7.7 Magnetic Separators 117 Problems 125 References 127 8 Magnetic Actuators Operated by AC 129 8.1 Skin Depth 129 8.2 Power Losses in Steel 130 8.3 Force Pulsations 135 8.4 Cuts in Steel 139 References 145 9 Magnetic Actuator Transient Operation 147 9.1 Basic Timeline 147 9.2 Size, Force, and Acceleration 148 9.3 Linear Magnetic Diffusion Times 150 9.4 Nonlinear Magnetic Infusion Times 156 9.5 Nonlinear Magnetic Effusion Time 164 9.6 Pulse Response of Nonlinear Steel 169 Problems 171 References 174 PART III SENSORS 175 10 Hall Effect and Magnetoresistive Sensors 177 10.1 Simple Hall Voltage Equation 177 10.2 Hall Effect Conductivity Tensor 179 10.3 Finite-Element Computation of Hall Fields 182 10.4 Hall Sensors for Position or Current 190 10.5 Magnetoresistance 193 10.6 Magnetoresistive Heads for Hard Disk Drives 194 10.7 Giant Magnetoresistive Spin Valve Sensors 195 Problems 198 References 198 11 Other Magnetic Sensors 201 11.1 Speed Sensors Based on Faraday's Law 201 11.2 Inductive Recording Heads 203 11.3 Proximity Sensors Using Impedance 206 11.4 Linear Variable Differential Transformers 210 11.5 Magnetostrictive Sensors 213 11.6 Fluxgate Sensors 215 11.7 Chattock Coil Field and Current Sensor 219 11.8 Squid Magnetometers 222 11.9 Magnetoimpedance and Miniature Sensors 223 11.10 MEMS Sensors 224 Problems 225 References 226 PART IV SYSTEMS 229 12 Coil Design and Temperature Calculations 231 12.1 Wire Size Determination for DC Currents 231 12.2 Coil Time Constant and Impedance 234 12.3 Skin Effects and Proximity Effects for AC Currents 235 12.4 Finite-Element Computation Of Temperatures 239 Problems 246 References 246 13 Electromagnetic Compatibility 249 13.1 Signal-To-Noise Ratio 249 13.2 Shields and Apertures 250 13.3 Test Chambers 255 Problems 260 References 260 14 Electromechanical Finite Elements 263 14.1 Electromagnetic Finite-Element Matrix Equation 263 14.2 0D and 1D Finite Elements for Coupling Electric Circuits 266 14.3 Structural Finite-Element Matrix Equation 272 14.4 Force and Motion Computation by Time Stepping 273 14.5 Typical Electromechanical Applications 275 Problems 286 References 286 15 Electromechanical Analysis Using Systems Models 289 15.1 Electric Circuit Models of Magnetic Devices 289 15.2 VHDL--AMS/Simplorer Models 296 15.3 MATLAB/Simulink Models 301 15.4 Including Eddy Current Diffusion Using a Resistor 307 15.5 Magnetic Actuator Systems for 2D Planar Motion 312 15.6 Optimizing Magnetic Actuator Systems 313 Problems 324 References 325 16 Coupled Electrohydraulic Analysis Using Systems Models 327 16.1 Comparing Hydraulics and Magnetics 327 16.2 Hydraulic Basics and Electrical Analogies 328 16.3 Modeling Hydraulic Circuits in Spice 330 16.4 Electrohydraulic Models in Spice and Simplorer 334 16.5 Hydraulic Valves and Cylinders in Systems Models 341 16.6 Magnetic Diffusion Resistor in Electrohydraulic Models 348 16.7 Optimization of an Electrohydraulic System 352 16.8 Magnetic Actuators for Digital Hydraulics 353 Problems 357 References 357 APPENDIX A: SYMBOLS, DIMENSIONS, AND UNITS 359 APPENDIX B: NONLINEAR B--H CURVES 361 APPENDIX C: FINAL ANSWERS FOR ODD-NUMBERED PROBLEMS 367 INDEX 371
Abstract:

An accessible, comprehensive guide on magnetic actuators and sensors, this fully updated second edition of Magnetic Actuators and Sensors includes the latest advances, numerous worked calculations, illustrations, and real-life applications. Read more...