Alternator

This alternator was built by French firm L. Sautter Lemonnier & Cie and was used to supply power for an alternating current arc lamp. The alternator has a stator, the stationary part, in the form of a Gramme ring. This is a ring of soft iron that has a series of coils wrapped around it, with the windings running from the outside to the inside. The unique aspect of the Gramme construction is the way in which the windings of a coil are wrapped around the iron core. In Zenobe Gramme's first design, in 1869, this ring is the rotating part, the rotor.