Published on Feb 28, 2016
The topic of magnetic braking has dramatically increased in popularity in recent years. Since 1987, numerous articles about magnetic braking were published. These articles describe both experiments dealing with magnetic braking, as well as the theory behind the phenomenon. Magnetic braking works because of induced currents and Lenz's law. If you attach a metal plate to the end of a pendulum and let it swing, its speed will greatly decrease when it passes between the poles of a magnet.
When the plate enters the magnetic field, an electric field is induced in metal and circulating eddy currents are generated. These currents act to oppose the change in flux through the plate, in accordance with Lenz's Law.
The currents in turn heat the plate, thereby reducing its kinetic energy. The practical uses for magnetic braking are numerous and commonly found in industry today. This phenomenon can be used to damp unwanted nutations in satellites, to eliminate vibrations in spacecrafts, and to separate nonmagnetic metals from solid waste
Mechatronics is a hybrid technological field which evolved from the combination of mechanical, electronics & Software engineering. Automobiles need high degree of safety to protect the occupants and their property. Bearing this in senses we come up with a new concept of Electric pulse Magnetic Braking (E.P.M.Braking).
When the driver applies force on the brake pedal the magnitude is sensed by the pressure transducer which in turn sends the actuating signals to microprocessor. This intelligent device sends pulsating D.C. current from the capacitor to the power pack.
The power pack develops sufficient torque to decelerate or stop the vehicle as per the driver's requirement. The torque produced is directly proportional to the force applied on the brake pedal, as the intensity of the actuating signal from the pressure transducer is directly proportional to the pulsating D.C. current supplied to the power pack.
Another important aspect of this braking system is that the power pack also acts as a generator, which results in additional power generation. We have also incorporated artificial intelligence. Logic gates for backup-circuit for safety and shift current for shifting the power pack from generating mode to braking mode and vice-versa to generator power.
The subject of magnetic braking is rarely discussed in introductory physics texts. To calculate the magnetic drag force on a moving metal object is generally difficult and implies solving Maxwell's equations in time-dependent situation. This may be one of the reasons why the phenomenon of magnetic braking, although conceptually simple to understand, has not attracted the attention of textbooks authors.
A simple approximate treatment is however possible in some special cases. In our seminar we will try to explain magnetic braking with the understandable (simple) theory. Reports in literature have made the theory behind this phenomenon easily accessible. First we will be interested in the braking of a rectangular sheet moving linearly through the magnet.