Amperite model 4V-199 "Self Adjusting" rheostat
date: label: date made
content: ca 1925
name: label: maker
content: Amperite
notes: label: Description (Brief)
content: A resistance unit in original box with instruction sheet. Marked: box: "Amperite No. 4V-199 / For Use with Tubes / UV-199 and C-299 / on the 4 or 4 1/2 Volt Battery. / Radiall Company, New York, NY." A rheostat for insertion in series with vacuum tube filament and "A" battery. Two metal end caps. The "self-adjusting" principle is not described, but presumably means variation in resistance of a wire element with increased current flow. Includes original box. Reference: Instruction leaflet in box (undated).
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Franklin Wingard
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.321917
label: catalog number
content: 321917
label: accession number
content: 241556
objectType: label: Object Name
content: rheostat
label: Object Name
content: variable resistance
physicalDescription: label: Measurements
content: unit: 2 in x 7/16 in; 5.08 cm x 1.11125 cm
label: Measurements
content: box: 3/4 in x 2 5/8 in x 3/4 in; 1.905 cm x 6.6675 cm x 1.905 cm