Eddy current damping of a magnet moving through a pipe

被引：52

作者：

Hahn, KD ^{[1
]}

Johnson, EM ^{[1
]}

Brokken, A ^{[1
]}

Baldwin, S ^{[1
]}

机构：

[1] Truman State Univ, Div Sci, Kirksville, MO 63501 USA

来源：

AMERICAN JOURNAL OF PHYSICS | 1998年 / 66卷 / 12期

关键词：

D O I：

10.1119/1.19060

中图分类号：

G40 [教育学];

学科分类号：

040101 ; 120403 ;

摘要：

A harmonic oscillator consisting of a neodymium magnet attached inside a spring is driven through resonance. Eddy currents, induced in pipes surrounding the magnet, result in a damping of the motion of the magnet. Our experiment makes precise measurements of the motion and damping of the magnet as we vary pipe composition, length, thickness, radius, and position. A theoretical analysis combining the standard differential equation for a damped, driven harmonic oscillator and Faraday's law of electromagnetic induction gives excellent agreement with the experimental results. This analysis allows for the calculation of electromagnetic damping for any pipe configuration which is coaxial with the magnet's motion and provides strong evidence for the eddy current damping analysis of the common demonstration of dropping a magnet down a conducting tube. (C) 1998 American Association of Physics Teachers.

引用

页码：1066 / 1076

页数：11

共 13 条

[1]

ABRAGAM A, 1983, PRINCIPLES NUCL MAGN, P84

[2] Magnetic damping: Analysis of an eddy current brake using an airtrack [J].