Applications of Superconductor - Semiconducting Materials - Dr. P Mani Engineering Physics 2 P.K. Palanichamy

Magnetic Levitated Train (Maglev train)

The magnetic levitated train does not move Over the rails but it floats above the rails.

Magnetic Levitation-Applications of Semiconductor - Semiconducting Materials - Dr. P Mani Engineering Physics 2 P.K. Palanichamy

Description and Working

This train has superconducting magnets built into its base. An aluminum guide way, above which the train will be set afloat by magnetic levitation. Magnetic levitation is brought about by enormous repulsion between two highly powerful magnetic fields,
one produced by the superconducting magnet inside the train and the other by the electric current in the aluminum guide way. The current in the guide way produces necessary magnetic field to levitate the train and help propelling the train forward. The train is provided with retractable wheels. The wheels serve almost the same purpose as those of aero plane. The train runs on the guide way just as the airplane takes off. Once the train is levitated in air, the wheels are retracted into the body. The height at which the train levitates above the guide way is about 10 to 15 cm. While coming to halt, the wheels are drawn out and the train slowly settles on the guide way and runs over a distance, just as an airplane does while landing. The current will continue to flow through the coil indefinitely without resistive losses.

Electrical Machines

Superconducting materials are used to manufacture small size electrical generators and transformers having efficiency of 99.90%.

 Electrical Measuring Instruments

Since very small voltages can cause large constant current in the superconducting materials, they are used in the construction of very sensitive electrical measuring instruments such as galvanometers.

 Power Cable

Superconducting materials are used in transmission of power through cable over very long distances without any power loss or drop in voltage.

Switching Devices

Since the Superconducting property of a substance can be quickly destroyed by the application of application of magnetic field, superconductors can be used in switching devices.

Computer Memory Devices

Since the superconductors can maintain the current without any loss for very long duration, they are used for memory storage in computers.Superconductors are used to design modulators Rectifiers, commutators, cryotrons and gating circuits

Write a short note on SQUIDs

(4 Marks)

Discuss the application cryotron.

(4 Marks)