Electromagnetic Levitation of a Disc

This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field distribution in the air gap allows analytical calculations to be performed. This paper illustrates the important connection between theory, mathematical modeling, design, simulation, and experimental verification and emphasizes the educational opportunities that this experiment brings to subjects such as control, magnetic circuits, power electronics, and electromechanical energy conversion. The proposal can be seen as an introduction to the main issues of mechatronics and is being used as example to raise the interest of undergraduate electrical engineering students.