Magnetic Actuators and Sensors
[BOOK DESCRIPTION]
A fully updated, easy-to-read guide on magnetic actuators and sensors The Second Edition of this must-have book for today's engineers includes the latest updates and advances in the field of magnetic actuators and sensors. Magnetic Actuators and Sensors emphasizes computer-aided design techniques-especially magnetic finite element analysis; offers many new sections on topics ranging from magnetic separators to spin valve sensors; and features numerous worked calculations, illustrations, and real-life applications.To aid readers in building solid, fundamental, theoretical background and design know-how, the book provides in-depth coverage in four parts: PART I: MAGNETICS * Introduction * Basic Electromagnetics * Reluctance Method * Finite-Element Method * Magnetic Force * Other Magnetic Performance Parameters PART II: ACTUATORS * Magnetic Actuators Operated by Direct Current * Magnetic Actuators Operated by Alternating Current * Magnetic Actuator Transient Operation PART III: SENSORS * Hall Effect and Magnetoresistive Sensors * Other Magnetic Sensors PART IV: SYSTEMS * Coil Design and Temperature Calculations * Electromagnetic Compatibility * Electromechanical Finite Elements * Electromechanical Analysis Using Systems Models * Coupled Electrohydraulic Analysis Using Systems Models With access to a support website containing downloadable software data files (including MATLAB(R) data files) for verifying design techniques and analytical methods, Magnetic Actuators and Sensors, Second Edition is an exemplary learning tool for practicing engineers and engineering students involved in the design and application of magnetic actuators and sensors.
[TABLE OF CONTENTS]
Preface xi
Preface to the First Edition xiii
List of 66 Examples xv
PART I MAGNETICS 1 (92)
1 Introduction 3 (6)
1.1 Overview of Magnetic Actuators 3 (1)
1.2 Overview of Magnetic Sensors 4 (1)
1.3 Actuators and Sensors in Motion 5 (2)
Control Systems
1.4 Magnetic Actuators and Sensors in 7 (2)
Mechatronics
References 8 (1)
2 Basic Electromagnetics 9 (24)
2.1 Vectors 9 (5)
2.1.1 Gradient 9 (2)
2.1.2 Divergence 11 (1)
2.1.3 Curl 11 (3)
2.2 Ampere's Law 14 (3)
2.3 Magnetic Materials 17 (5)
2.4 Faraday's Law 22 (3)
2.5 Potentials 25 (3)
2.6 Maxwell's Equations 28 (5)
Problems 29 (2)
References 31 (2)
3 Reluctance Method 33 (10)
3.1 Simplifying Ampere's Law 33 (4)
3.2 Applications 37 (3)
3.3 Fringing Flux 40 (1)
3.4 Complex Reluctance 41 (1)
3.5 Limitations 41 (2)
Problems 42 (1)
References 42 (1)
4 Finite-Element Method 43 (12)
4.1 Energy Conservation and Functional 43 (2)
Minimization
4.2 Triangular Elements for Magnetostatics 45 (1)
4.3 Matrix Equation 46 (3)
4.4 Finite-Element Models 49 (6)
Problems 53 (1)
References 53 (2)
5 Magnetic Force 55 (24)
5.1 Magnetic Flux Line Plots 55 (5)
5.2 Magnetic Energy 60 (1)
5.3 Magnetic Force on Steel 61 (4)
5.4 Magnetic Pressure on Steel 65 (1)
5.5 Lorentz Force 66 (1)
5.6 Permanent Magnets 67 (5)
5.7 Magnetic Torque 72 (1)
5.8 Magnetic Volume Forces on Permeable 73 (6)
Particles
Problems 75 (1)
References 76 (3)
6 Other Magnetic Performance Parameters 79 (14)
6.1 Magnetic Flux and Flux Linkage 79 (3)
6.1.1 Definition and Evaluation 79 (1)
6.1.2 Relation to Force and Other 80 (2)
Parameters
6.2 Inductance 82 (4)
6.2.1 Definition and Evaluation 82 (3)
6.2.2 Relation to Force and Other 85 (1)
Parameters
6.3 Capacitance 86 (2)
6.3.1 Definition 86 (1)
6.3.2 Relation to Energy and Force 86 (2)
6.4 Impedance 88 (5)
Problems 91 (1)
References 91 (2)
PART II ACTUATORS 93 (82)
7 Magnetic Actuators Operated by DC 95 (34)
7.1 Solenoid Actuators 95 (11)
7.1.1 Clapper Armature 95 (7)
7.1.2 Plunger Armature 102 (4)
7.2 Voice Coil Actuators 106 (2)
7.3 Other Actuators Using Coils and 108 (1)
Permanent Magnets
7.4 Proportional Actuators 109 (3)
7.5 Rotary Actuators 112 (2)
7.6 Magnetic Bearings and Couplings 114 (3)
7.7 Magnetic Separators 117 (12)
Problems 125 (2)
Reference 127 (2)
8 Magnetic Actuators Operated by AC 129 (18)
8.1 Skin Depth 129 (1)
8.2 Power Losses in Steel 130 (5)
8.2.1 Laminated Steel 130 (1)
8.2.2 Equivalent Circuit 131 (3)
8.2.3 Solid Steel 134 (1)
8.3 Force Pulsations 135 (4)
8.3.1 Force with Single AC Coil 135 (2)
8.3.2 Force with Added Shading Coil 137 (2)
8.4 Cuts in Steel 139 (8)
8.4.1 Special Finite-Element Formulation 139 (1)
8.4.2 Loss and Reluctance Computations 140 (5)
Problems 145 (1)
References 145 (2)
9 Magnetic Actuator Transient Operation 147 (28)
9.1 Basic Timeline 147 (1)
9.2 Size, Force, and Acceleration 148 (2)
9.3 Linear Magnetic Diffusion Times 150 (6)
9.3.1 Steel Slab Turnon and Turnoff 150 (5)
9.3.2 Steel Cylinder 155 (1)
9.4 Nonlinear Magnetic Infusion Times 156 (8)
9.4.1 Simple Equation for Steel Slab 156 (1)
with "Step" B--H
9.4.2 Transient Finite-Element 157 (4)
Computations for Steel Slabs
9.4.3 Simple Equation for Steel 161 (1)
Cylinder with "Step" B--H
9.4.4 Transient Finite-Element 161 (3)
Computations for Steel Cylinders
9.5 Nonlinear Magnetic Effusion Time 164 (5)
9.5.1 Planar Effusion in Nonlinear 164 (3)
Steel Slab
9.5.2 Axisymmetric Effusion in 167 (2)
Nonlinear Steel Cylinder
9.6 Pulse Response of Nonlinear Steel 169 (6)
Problems 171 (3)
References 174 (1)
PART III SENSORS 175 (54)
10 Hall Effect and Magnetoresistive Sensors 177 (24)
10.1 Simple Hall Voltage Equation 177 (2)
10.2 Hall Effect Conductivity Tensor 179 (3)
10.3 Finite-Element Computation of Hall 182 (8)
Fields
10.3.1 Unsymmetric Matrix Equation 182 (1)
10.3.2 2D Results 183 (4)
10.3.3 3D Results 187 (3)
10.4 Hall Sensors for Position or Current 190 (3)
10.4.1 Toothed Wheel Position Sensor 190 (2)
10.4.2 Position Sensors using Multipole 192 (1)
Magnets
10.4.3 Hall Effect Current Sensors 192 (1)
10.5 Magnetoresistance 193 (1)
10.5.1 Classical Magnetoresistance 193 (1)
10.5.2 Giant Magnetoresistance 193 (1)
10.5.3 Newer Forms of Magnetoresistance 194 (1)
10.6 Magnetoresistive Heads for Hard Disk 194 (1)
Drives
10.7 Giant Magnetoresistive Spin Valve 195 (6)
Sensors
Problems 198 (1)
References 198 (3)
11 Other Magnetic Sensors 201 (28)
11.1 Speed Sensors Based on Faraday's Law 201 (2)
11.2 Inductive Recording Heads 203 (3)
11.3 Proximity Sensors Using Impedance 206 (4)
11.3.1 Stationary Eddy Current Sensors 206 (3)
11.3.2 Moving Eddy Current Sensors 209 (1)
11.4 Linear Variable Differential 210 (3)
Transformers
11.5 Magnetostrictive Sensors 213 (2)
11.6 Fluxgate Sensors 215 (4)
11.7 Chattock Coil Field and Current 219 (3)
Sensor
11.8 Squid Magnetometers 222 (1)
11.9 Magnetoimpedance and Miniature 223 (1)
Sensors
11.10 MEMS Sensors 224 (5)
Problems 225 (1)
References 226 (3)
PART IV SYSTEMS 229 (130)
12 Coil Design and Temperature Calculations 231 (18)
12.1 Wire Size Determination for DC 231 (3)
Currents
12.2 Coil Time Constant and Impedance 234 (1)
12.3 Skin Effects and Proximity Effects 235 (4)
for AC Currents
12.4 Finite-Element Computation Of 239 (10)
Temperatures
12.4.1 Thermal Conduction 239 (2)
12.4.2 Thermal Convection and Thermal 241 (1)
Radiation
12.4.3 AC Magnetic Device Cooled by 242 (4)
Conduction, Convection, and Radiation
Problems 246 (1)
References 246 (3)
13 Electromagnetic Compatibility 249 (14)
13.1 Signal-To-Noise Ratio 249 (1)
13.2 Shields and Apertures 250 (5)
13.3 Test Chambers 255 (8)
13.3.1 TEM Transmission Lines 255 (2)
13.3.2 TEM Cells 257 (1)
13.3.3 Triplate Cells 257 (3)
Problems 260 (1)
References 260 (3)
14 Electromechanical Finite Elements 263 (26)
14.1 Electromagnetic Finite-Element 263 (3)
Matrix Equation
14.2 0D and 1D Finite Elements for 266 (6)
Coupling Electric Circuits
14.3 Structural Finite-Element Matrix 272 (1)
Equation
14.4 Force and Motion Computation by Time 273 (2)
Stepping
14.5 Typical Electromechanical 275 (14)
Applications
14.5.1 DC Solenoid with Slowly Rising 275 (1)
Current Input
14.5.2 DC Solenoid with Step Voltage 276 (3)
Input
14.5.3 AC Clapper Solenoid Motion and 279 (3)
Stress
14.5.4 Transformers with Switches or 282 (2)
Sensors
14.5.5 Reciprocating Magnetic Actuators 284 (2)
Problems 286 (1)
References 286 (3)
15 Electromechanical Analysis Using Systems 289 (38)
Models
15.1 Electric Circuit Models of Magnetic 289 (7)
Devices
15.1.1 Electric Circuit Software 289 (1)
Including SPICE
15.1.2 Simple LR Circuits 290 (2)
15.1.3 Tables of Nonlinear Flux Linkage 292 (1)
and Force
15.1.4 Analogies for Rigid Armature 293 (1)
Motion
15.1.5 Maxwell SPICE Model of Bessho 293 (2)
Actuator
15.1.6 Simplorer Model of Bessho 295 (1)
Actuator
15.2 VHDL--AMS/Simplorer Models 296 (5)
15.2.1 VHDL--AMS Standard IEEE Language 296 (1)
15.2.2 Model of Solenoid Actuator 297 (4)
15.3 MATLAB/Simulink Models 301 (6)
15.3.1 Software 301 (1)
15.3.2 MATLAB Model of Voice Coil 302 (5)
Actuator
15.4 Including Eddy Current Diffusion 307 (5)
Using a Resistor
15.4.1 Resistor for Planar Devices 308 (2)
15.4.2 Resistor for Axisymmetric Devices 310 (2)
15.5 Magnetic Actuator Systems for 2D 312 (1)
Planar Motion
15.6 Optimizing Magnetic Actuator Systems 313 (14)
15.6.1 3D Analysis of Fuel Injector 314 (4)
System
15.6.2 Analysis of 3D Solenoid for 318 (6)
Valve Actuation
Problems 324 (1)
References 325 (2)
16 Coupled Electrohydraulic Analysis Using 327 (32)
Systems Models
16.1 Comparing Hydraulics and Magnetics 327 (1)
16.2 Hydraulic Basics and Electrical 328 (2)
Analogies
16.3 Modeling Hydraulic Circuits in Spice 330 (4)
16.4 Electrohydraulic Models in Spice and 334 (7)
Simplorer
16.5 Hydraulic Valves and Cylinders in 341 (7)
Systems Models
16.5.1 Valves and Cylinders 341 (2)
16.5.2 Use in SPICE Systems Models 343 (5)
16.6 Magnetic Diffusion Resistor in 348 (4)
Electrohydraulic Models
16.7 Optimization of an Electrohydraulic 352 (1)
System
16.8 Magnetic Actuators for Digital 353 (6)
Hydraulics
Problems 357 (1)
References 357 (2)
Appendix A Symbols, Dimensions, and Units 359 (2)
Appendix B Nonlinear B--H Curves 361 (6)
Appendix C Final Answers for Odd-Numbered 367 (4)
Problems
Index 371