Contribution to the study of eddy currents in a ring of Thomson

Abstract

The eddy currents induced in metals by a variable magnetic field are always a topic of interest, both theoretical and practical (electricity meters, furnaces, metal detectors) and in Physical teaching.

These flows occur, for example, a mounting ring Thomson type: when this core projecting from the coil extends to introduce a ring, often aluminum, appears magnetic levitation phenomenon due to repulsion between the coil current and the induced in the ring.

Our objective with this work has focused on obtaining the decreasing exponentially repulsive force that pushes the ring vs. height it reaches equilibrium. We carry out the following experiments:

1. Study of the repulsive force on the ring, in relation to height in the core (here we introduce a novel method for not need to turn the coil-ring assembly).

2. Study dissipative effect of the current in the ring, analyzing the temperature rise in container with water, heat generated by receiver ring. Additionally, we propose methods to study the oscillation frequency of the ring and the gap between the current in it in relation to the inducer.

DOI: http://dx.doi.org/10.5377/rct.v0i13.1717

Revista Ciencia y Tecnología, No. 13, diciembre 2013: 110-123