Siemens & Halske electrical bridge
date: label: date made
content: ca 1906
name: label: maker
content: Siemens & Halske
notes: label: Description (Brief)
content: This alternating current bridge consists of a circular base, on the outer circumference of which is a slide wire. A contact on a radius arm makes contact with the slide wire to form two arms of a Wheatstone bridge. Graduated disc with movable black handled pointer. Plug in resistors are arranged on the base as the other arms of the bridge. Wooden phones with leather handles are used as detectors, manufactured by Siemens and Halske, Berlin, Germany. Marked with S&H logo. The bridge is used to measure the inductances and effective resistances of circuits, such as coils, etc. The source of the testing current was an alternating current generator made by the same firm. It consisted of a toothed wheel revolving past a magnetic circuit including a coil in which alternating current was generated at frequencies up to 2,000 cycles per second.
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.313272.01
label: catalog number
content: 313272.01
label: accession number
content: 181342
objectType: label: Object Name
content: Bridge
label: Object Name
content: resistance bridge
label: Object Name
content: bridge resistance
label: Other Terms
content: Bridge; Measuring Devices
physicalDescription: label: Measurements
content: overall: 10 in; x 25.4 cm