Museo Galileo
Virtual Museum
Magneto-electric machine by Pixii
    • Setting:
      Room XVI
    • Inventor:
      Hippolyte Pixii
    • Maker:
      Hippolyte Pixii
    • Place:
    • Date:
      ca. 1832
    • Materials:
      mahogany, brass, iron, steel
    • Dimensions:
      total height 1180 mm, base 610x380 mm
    • Inventory:
    • Magneto-electric machine by Pixii (Inv. 552)
    • Magneto-electric machine by Pixii (Inv. 552)

One of the earliest magneto-electric generators for producing electric current. A mahogany frame supports a horseshoe electromagnet suspended from the upper cross-piece (today only the electromagnet's iron core survives; the coils are missing). The rest of the machine is mounted on a separate base, secured to the base of the frame by means of large butterfly screws. A horseshoe permanent magnet is rotated by means of a geared handle under the poles of the suspended electromagnet. This produces an induced alternating current that is rectified by Ampère's rocking commutator, actuated by a cam on the axis of the armature. Hippolyte Pixii made instruments for Jean-François-Dominique Arago and André-Marie Ampère and, with Ampère's help, developed this machine in 1832. Although basically a laboratory apparatus, this generator was a landmark in the transformation of mechanical energy into electricity.