THE LEARNING GOALS FOR THIS CHAPTER ARE:
Understand the concepts of mutual inductance, coefficient of coupling, and turns ratio
Know how to calculate voltages and currents in circuits containing mutual inductance
Know how to calculate voltages and currents in circuits containing ideal transformers
Magnetic Levitation Train The Pony Express is to today's electronic mail as the stagecoach of the Old West is to which modern miracle of land transportation? Did you guess a speeding locomotive? Very good, but a better answer is the magnetic levitation train—abbreviated MagLev. These passenger trains—the world's fastest—float on a magnetic field about 10 mm above the guideway, propelled by a linear induction motor. Shanghai Pudong International Airport has a MagLev that reaches speeds over 300 mph, 60% faster than the famed Bullet Trains of Japan. It gives the smoothest ride ever, coasting along under magnetic power.
MagLev trains are used primarily when two large cities are to be connected for passenger service. MagLev systems have several advantages: lower maintenance because there are no moving parts; no friction, only air resistance; an absence of wheel noises; no exhaust fumes; and amazing speed. The only drawbacks are higher costs and lack of compatibility with existing infrastructure.
This chapter introduces a central concept of MagLev technology: ...