Eddy Currents and Non Ferrous Metals.

Strictly speaking Z those are not Eddy currents. Take a maglev train. There are a lot of coils that induce a current into a very solid piece of Aluminium. The current in the Ali produces a magnetic field, which then interacts with the one inducing the current, and applies a force to the aluminum.  When I was at school there was a "demountable transformer" with a mains winding. The core could be left open, giving an upright core section about 18" long. One could float rings of Ali foil and stuff on the field around the core. I made a copper ring, fitting over the core but 10mm thick and 25mm wide, with a silver-soldered joint. Resistance a few micro-ohms. The mains coil was about 1 turn per volt so I had tens of thousands of amps flowing in the ring. It got very hot quite quickly! The force on this was very substantial (my idea) and made a very effective ring gun which made big marks in the ceiling when the power was applied. In fact, it took several kilowatts, and the ring would almost support a suitable boy, say 50kg, and push him at the ceiling! The teacher was not awfully impressed but was seen using the ring to show another class how powerful magnetic fields could be. The Americans used something similar as a catapult on a nuclear-driven Aircraft Carrier, it accelerated planes to a couple of hundred miles an hour in about 50 metres, the pilots complained as it was many more "G" than the old steam type which was considerably longer and required the plane engine at full afterburn too. The electric one saved significant fuel in the fighter, a great advantage.


You can see Eric Laithwaite demonstrating both of these things on youtube, but they are not Eddy current driven, just normal induction.

Strictly speaking Z those are not Eddy currents. Take a maglev train. There are a lot of coils that induce a current into a very solid piece of Aluminium. The current in the Ali produces a magnetic field, which then interacts with the one inducing the current, and applies a force to the aluminum.  When I was at school there was a "demountable transformer" with a mains winding. The core could be left open, giving an upright core section about 18" long. One could float rings of Ali foil and stuff on the field around the core. I made a copper ring, fitting over the core but 10mm thick and 25mm wide, with a silver-soldered joint. Resistance a few micro-ohms. The mains coil was about 1 turn per volt so I had tens of thousands of amps flowing in the ring. It got very hot quite quickly! The force on this was very substantial (my idea) and made a very effective ring gun which made big marks in the ceiling when the power was applied. In fact, it took several kilowatts, and the ring would almost support a suitable boy, say 50kg, and push him at the ceiling! The teacher was not awfully impressed but was seen using the ring to show another class how powerful magnetic fields could be. The Americans used something similar as a catapult on a nuclear-driven Aircraft Carrier, it accelerated planes to a couple of hundred miles an hour in about 50 metres, the pilots complained as it was many more "G" than the old steam type which was considerably longer and required the plane engine at full afterburn too. The electric one saved significant fuel in the fighter, a great advantage.


You can see Eric Laithwaite demonstrating both of these things on youtube, but they are not Eddy current driven, just normal induction.