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The Ruhmkorff coil, named after its inventor, a 19th century physicist, has almost retained the same appearance since its creation. The principle is simple: it is a transformer, made up of a core of soft iron wires tightly wound together. The primary circuit is wound around this core, consisting of a thick wire. Around this winding is the secondary circuit, made up of a very large number of turns of finely insulated thin wires. By creating abrupt interruptions in the primary current, an induction phenomenon is induced in the secondary circuit, resulting in a very high induced voltage. The spark that appears between the rod and the metal disk, above the coil, allows the visualisation of the voltage obtained. For a demonstration, you can watch these videos: Instagram and YouTube
Ruhmkorff Coil (Leybold)
Dimensions: L 45 x W 24 x H 33 cm, 1980s
Located at the Faculty of Science and Technology of Nancy, Poincaré building
The University of Lorraine, in partnership with CNAM and the Metropolis of Grand Nancy, is leading the PATSTEC (Scientific and Technical Contemporary Heritage) mission at the scale of the Lorraine territory. More information here.
Photo: Arnaud Codazzi
