Gramme direct current dynamo
date: label: Date made
content: c1878
label: date made
content: ca 1878
name: label: maker
content: Schwerd and Scharnweber
label: maker
content: Gramme
notes: label: Description (Brief)
content: No extant maker's markings. A pair of field poles, painted green and lying above one another, have a magnetic circuit that ends in circular arcs that fit the armature snugly. The armature is the ring armature of Gramme and is also painted green. There are 16 commutator segments. The position of the brushes cannot be changed. The end plates of the poles are wooden, painted brown. Unit mounted on a metal base along with a hand-cranked wheel. A belt (missing) connects the wheel to a pulley set on the armature shaft opposite the commutator. Dynamo appears similar to commercial Daft motor illustrated in Electrical World, July 23, 1887. Reference: Groenendijk Catalog, page 29, item 5h-37; Wormell, Electricity in the Service of Man (London: Cussell & Co., 1886) pages 246-251, for theory of Gramme ring armature.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.315597
label: catalog number
content: 315597
label: accession number
content: 216300
label: collector/donor number
content: 5h-37
objectType: label: Object Name
content: Generator
label: Object Name
content: electrical generator
physicalDescription: label: Measurements
content: overall: 18 1/4 in x 22 3/4 in x 9 1/2 in; 46.355 cm x 57.785 cm x 24.13 cm