How have eddy currents been utilised in electromagnetic braking?
The most useful sort of electromagnetic braking is what is called regenerative braking. This is used in trains and some other electric vehicles. To decelerate, the electric motor is used as a generator and converts the train’s kinetic energy back to electrical energy which is fed back in to the grid. Great for energy conservation, and engineers try to maximise this. However, this is not really eddy current braking, because ‘eddy currents’ is usually used only when the currents waste energy. Eddy current braking is used on some trains: the train carries a powerful electromagnet positioned near the rails produces eddy currents whose magnetic field opposes the motion of the magnets on the train. It has the advantage over mechanical brakes of having no pads to replace and being silent and smooth. It is of course more wasteful than regenerative braking. Eddy current braking has the feature that it is strong at high speeds and weak at low. This is sometimes a disadvantage (e.g. for parking!)
