Western Electric type D-81431 polar relay
name: label: Maker
content: Western Union Corporation
label: maker
content: Thomas A. Edison, Inc.
label: maker
content: Western Electric
notes: label: Description
content: Telegraph relays amplify an electrical signal in a telegraph line. Telegraph messages travel as a series of electrical pulses through a wire from a transmitter to a receiver. The pulses fade in strength as they travel through the wire, limiting the distance a message can be sent. Relays remedy that problem by detecting a weak signal and automatically re-transmitting that signal down the line using a local power source.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Communications
creditLine: label: Credit Line
content: from Western Union Corporation
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.332196
label: accession number
content: 294351
label: catalog number
content: 332196
objectType: label: Object Name
content: relay
label: Object Name
content: polar relay
label: Object Name
content: telegraph relay
physicalDescription: label: Physical Description
content: metal (part material)
label: Physical Description
content: wood (part material)
label: Physical Description
content: glass (part material)
label: Physical Description
content: plastic (part material)
label: Measurements
content: overall: 5 in x 5 1/4 in x 5 in; 12.7 cm x 13.335 cm x 12.7 cm