(NEW) Help with Electromagnetic Braking Principles

[gbuenvia]

So my friends and I are working on a Mechanical Engineering design project. I'm looking to create an electromagnetic brake that would be applied in a linear fashion as opposed to most that work in a rotation fashion (i.e. wheels). I'm looking to use these electromagnets on an aluminum rail which would then be attached to an already levitating train/pod (the magnets don't play a factor in levitation, only braking). I was wondering what necessary equations would be needed for the magnets, relating drag force to the force of a moving pod as well as the necessary current/power to create the force.

Also, I was wondering if there are any websites that currently have these types of brakes or electromagnets.

Thanks! (again I'm new to the forum so a little unsure of how this whole thing works)

[JAlberts]

Do a web search for DC Electric Motors. These motors, just as a standard electric motor can be an electric generator as well. In your case, by placing an approriate resistance load across the motor leads you can create an electric brake, similar to the regenerative braking now used on electric automobiles.

[JAlberts]

As an addendum to my above post, you should be aware that this type of linear braking has its limits because the amount of braking force is dependent upon the relative speed between the motor coil and the adjacent magnet field; and, will still depend upon additional braking system to bring a vehicle to a complete stop within any reasonable distance.

[gbuenvia]

Hey JAlberts, thanks for the reply. I'm a little confused on how the DC Electric Motor would work in my given case. Essentially, we need an electromagnet to induce a current onto a rail of aluminum that would provide a deceleration force on a pod (almost like a rail train). However, the thing with the pod is that it's suspended by air bearings, and the center rail is there for the pod to "sit" on.

Thanks!

[JAlberts]

Google "Magnetic induction brakes" and you will find a number of sites addressing your application. Apparently, safety braking on roller coasters is one current use of this type of brake except that they use permanent magnets to protect from power failures.