Double-current telegraph key, 1830-1900
- Made:
- 1830-1900 in United Kingdom
- maker:
- General Post Office
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LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence
Buy this image as a print
BuyLicense this image for commercial use at Science and Society Picture Library
LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence
Buy this image as a print
BuyLicense this image for commercial use at Science and Society Picture Library
LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence
Buy this image as a print
BuyLicense this image for commercial use at Science and Society Picture Library
License
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Double-current telegraph key, probably made and used by the Post Office, British, 1830-1900.
With a single-current telegraph key the position of the relay is restored to the normal position when current ceases by a magnetic bias or by a spring in tension. In other words, signal currents only flow in the line when the key is depressed. In the double-current system a current in the reverse direction is used to restore the relay to the spacing side. This example is similar to those used with the Bright's bell, or acoustic telegraph.
Details
- Category:
- Telecommunications
- Object Number:
- 1953-111
- Materials:
- copper (alloy), metal (unknown), mother-of-pearl and wood (unidentified)
- type:
- telegraph
- taxonomy:
-
- component - object
- credit:
- Donated by the Institution of Electrical Engineers
