New roller coasters braking using eddy current brakes.
Principle and structure of the eddy current brake
Important for understanding the function of the eddy current brake is the knowledge that in conductive objects eddy currents are induced once they move in a variable magnetic field. These currents can then be selectively used to decelerate the subject.
- One can initially an object that is electrically conductive - about a metal plate - commuting through a magnetic field. After a short time the subject loses massively speed and stops finally.
- This observation can be using the law of induction and Lenz's Law explained:
- The object moves through its movement from the permanent magnetic field in and out, thus he learns each different magnetic fields - even a strong and once even none or only a Dim. In addition, he has compared to the magnetic field at a relative speed, resulting in the induction of current leads hence in him.
- The faster the object in reciprocates magnetic field, the greater the current (eddy current), which is thereby induced in him. The Lenz's law states that, the induced current counter to its emergence acts exactly - so the object decelerates. This works by the eddy current will flow, so that it causes a magnetic field which is opposed to that of the existing magnetic field - to be "objective" is to re-establish a field-free state.
Advantages and applications of the eddy current brake
- The biggest feature of the eddy current brake is that it comes completely without contact between the braking device and to be braked parts. Wear do not occur in this context, guaranteeing a great durability of the brake.
- Use find the eddy current brakes in various areas. Rail vehicles such as trains, fitness equipment, amusement machines, trucks or even measuring instruments benefit from the strong and particularly failsafe brakes.
- A disadvantage of only that under circumstances creating a strong heating of the metal parts, usually the materials used are equal to these temperatures.
The idea of the eddy current brakes was indeed patented as early as 1892, but they came so, as we know, until much later used. Meanwhile, they are particularly indispensable for rail vehicles.