Eddie current braking demonstration

Copper is non magnetic. However motion from magnets induce "Eddie currents" in the copper. These oppose the magnetic field and thus slow down the rotor. Notice how the opposing force increases the AMP reading. The motor draws more power with opposing forces, and this "request" is actually transferred backwards through the wireless power coils.

It is a perfect demonstration of conservation of energy. It may be counter intuitive to some that the AMP reading would increase. It is easy to think of how "power information" goes from the powered coil, to the motor coil. If you turn up the power, the motor will get more power. But it is hard to think of the power going the other way. When the motor is opposed by friction, or in this case eddie currents, it actually generates its own opposing forces on the coils in the motor, which oppose the forces from the wireless coil, which opposes forces from the power supply, working it harder to stay at a constant voltage.

So power goes through the chain from left to right, and any opposition (resistance) ripples back in the opposite direction.

The use of this technology for vehicle brakes is being experimented upon as it is a frictionless, and non destructive method. However, the copper would still become hot as a release of the energy.

Eddie currents can also be seen in induction welding, induction stoves, disc launchers, magnetic levitation (hover skateboard), and slow moving magnets through a copper pipe.