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.
- Science Museum, Information Age Gallery: Exchange
- Object Number:
- electric switch
- component - object
- Donated by BT Heritage and Archives
- Permanent collection
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