Thomson Houston current indicator
date: label: date made
content: 1889
name: label: maker
content: Thomson-Houston Electric Company
notes: label: Description (Brief)
content: This ammeter consists of an instrument in a glass-top mahogany case. Marked: "Current Indicator / No. 2271 / Capacity 200 Amperes / Patented Oct. 22. 1889 / Manufactured by / Thomson-Houston Electric Co. / Lynn, Mass. U.S.A." The current to be measured passes through a single turn conductor, in which is pivoted eccentrically a soft iron movement controlled by gravity. As a result of the eccentricity, the current tends to rotate the iron piece into a position nearer to the conductor, causing a scale deflection as a measure of the current. In all ammeters of this general type, it was necessary to bring the entire current to be measured to the instrument regardless of its magnitude. This necessity was eliminated and a great saving in copper effected by the use of the permanent magnet moveable coil instrument and heavy current shunt invented by Dr. Edward Weston.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Weston Electrical Instrument Corp., thru John H. Miller
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.313279
label: catalog number
content: 313279
label: accession number
content: 181342
objectType: label: Object Name
content: Ammeter
label: Other Terms
content: Ammeter; Measuring Devices
physicalDescription: label: Measurements
content: overall: 10 1/2 in x 13 1/2 in x 4 in; 26.67 cm x 34.29 cm x 10.16 cm