File:Barkhausen effect apparatus.jpg
Barkhausen_effect_apparatus.jpg (553 × 227像素,文件大小:33 KB,MIME类型:image/jpeg)
摘要
描述Barkhausen effect apparatus.jpg |
English: A replica of the experimental apparatus used by German physicist Heinrich Barkhausen in 1919 to detect the Barkhausen effect. This is a hissing or series of crackling sounds heard in an earphone attached to a coil of wire around an iron core when the magnetic field through it changes. When a magnet is brought near a piece of iron, the domain walls of the magnetic domains move, reorienting the domains so the , The sound is caused by the domain walls getting hung up on defects in the crystal lattice and then "snapping" past them. This effect is responsible for the magnetization hysteresis curve of the magnetic material. The apparatus consists of a coil of wire wound around an iron core (center) with the coil attached to a vacuum tube amplifier and a pair of earphones. A horseshoe magnet (right) that can be rotated by a knob is next to the iron. When the magnet is rotated by 180°, its magnetic field which passes through the iron core changes from one direction to the opposite direction. The Barkhausen noise is heard in the earphone while the magnet is being turned. |
日期 | |
来源 | Retrieved September 21, 2015 from Irving J. Saxl, "Fundamentals of Electricity" in Radio News magazine, Teck Publications, New York, Vol. 18, No. 2, August 1936, p. 94, fig. 7 on Google Books |
作者 | Irving J. Saxl |
授权 (二次使用本文件) |
This 1936 issue of Radio News magazine would have the copyright renewed in 1964. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. Search of the Renewals for Periodicals for 1963, 1964, and 1965 show no renewal entries for Radio News. Therefore the copyright was not renewed and it is in the public domain. |
许可协议
Public domainPublic domainfalsefalse |
本作品属于公有领域,因为其是于1929~1963年之间在美国出版,且无论其是否具有著作权声明,它并未进行著作权更新。更多信息请参考Commons:Hirtle chart/zh及著作权更新日志。请注意该作品在其他对美国作品不适用较短期限法则的司法管辖区仍然受著作权保护(基于作者的逝世日期),如加拿大(作者过世后70年)、中国大陆(作者过世后50年,不包括香港和澳门)、德国(作者过世后70年)、墨西哥(作者过世后100年)、瑞士(作者过世后70年)及其他有本地条约的国家。
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此文件中描述的项目
描绘内容
8月 1936
媒体类型 简体中文(已转写)
image/jpeg
数据大小 简体中文(已转写)
33,618 字节
227 像素
553 像素
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