Strowger step-by-step automatic telephone exchange switch, 1897-1898

Made:
1897-1898 in United States
maker:
Strowger Automatic Telephone Company

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Science Museum Group Collection
© The Board of Trustees of the Science Museum

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Strowger step-by-step automatic telephone exchange switch, made by the Strowger Automatic Telephone Company, United States, 1897-1898

Strowger step-by-step automatic telephone exchange switch, made by the Strowger Automatic Telephone Company, United States, 1897-1898.

The Strowger switches operated using electromagnets to raise the switch arm. The first digit dialled raised the switch arm to the required level, which the second digit caused it to rotate to the desired contact point. This method of operation led to them being called either 'two motion' or 'step-by-step' switches. Up to 100 line connections were available on an exchange of this size.

Details

Category:
Telecommunications
Object Number:
1926-1052
Materials:
leatherette, metal (unknown), plastic (unidentified) and rubber (unidentified)
type:
electric switch
taxonomy:
  • component - object
credit:
Donated by BT Heritage and Archives