I was just wondering- how do rheostatic/electric brakes work? In airplanes, there is a thing called a thrust reverser (The thing when the engines open up) where air is directed forwards to slow the plane down. My idea is that it pushes the wheel forwards to stop the train.
It’s the Back EMF which is used as a braking force if I remember correctly. Please correct me if I’m wrong.
Yes- a.k.a. regenerative braking. The traction motors effectively become generators and the effort it takes to turn them is what slows the train. Electric locomotives can feed the power this generates back into the supply.
Actually, to correct my own post, rheostatic and regenerative braking aren't the same thing. Both work as described using the traction motors to generate electricity and the effort that takes yields the braking effect. The difference is in what becomes of the power. With regenerative braking the power can be returned to the catenary or third rail through the pantograph or shoe. Rheostatic braking is used by Diesel-electrics which, of course, don't have a supply to feed power back to. Instead it's dissipated through banks of resistors.
