» Gramme machine (0652)

Immagini

DESCRIPTION

Exhibit 652 is an electromagnetic generator of direct current designed by Zénobe Théophile Gramme (1826 - 1901), a Belgian electrical engineer.

The apparatus consists of a ring similar to that of Pacinotti (see exhibit 574) that rotates in the gap of a strong Jamin magnet to generate current. There are two brushes that slide on the rotor to collect direct current. Foto-2

The rotor is a ring formed by soft iron wires around which are wound 30 coils of red and black isolated wire. The entire assembly is mounted on a wood frame in the form of a table that supports a pulley and belt system to activate the dynamo using a pedal connected to a spring. This instrument is a reversible machine; it can be used both as a generator of electricity as well as a motor.

The Jamin magnet is a magnet composed of a certain number of thin steel strips, first magnetized separately and then arranged in the horseshoe form. The strips are fixed with screws to the soft iron armature, in turn maintained at a constant distance one from the other by external copper strips. The internal steel strips of constant length are held together by their elasticity. Respect to other magnets of the same period the field strength of Jamin magnets was very high.

ISCRIZIONI

Sulla base è inciso: "Gramme INV.¶
B.TE S:G:D:G.¶
BREGUET FT.¶
No. 148"

BIBLIOGRAPHY

[1] URL [ http://en.wikipedia.org/wiki/Gramme_machine ]
[2] La machine de Gramme : sa théorie et sa description / par Antoine Brégue" Gauthier-Villars (Paris) 1880 Bréguet, Antoine (1851-1882) URL=URL [ http://gallica.bnf.fr/ark:/12148/bpt6k780110 ]
[3] URL [ http://softs.polytechnique.fr/dsi/ksup/MuseeVirtuel/W3patrimoine/index.php?PAGE=Gramme&TYPE=electromagnetisme ]
[4] P. Fleury e J.P. Mattieu,"Elettrostatica Corrente continua Magnetismo", Zanichelli Bologna, Cap. 22, Pag. 521.

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