Understanding the Use of Magnetic Attraction in EMS Maglev Trains

[Paul Aitken]

I'm trying to find out why EMS maglev trains use magnetic attraction instead of repulsion. Given that the attractive force diminishes to the square with distance, the countervailing forces would have to match exactly would they not? It seems to me that with like polarity between the track and train any deviation in the distance between the two would be self-correcting. As the train got closer to the track, magnetic repulsion would increase.

 

[Greg Bernhardt]

Welcome to PF!

 

[Evo]

I'm trying to find out why EMS maglev trains use magnetic attraction instead of repulsion. Given that the attractive force diminishes to the square with distance, the countervailing forces would have to match exactly would they not? It seems to me that with like polarity between the track and train any deviation in the distance between the two would be self-correcting. As the train got closer to the track, magnetic repulsion would increase.

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