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.
- Object Number:
- electric switch
- component - object
- Donated by BT Heritage and Archives
- Permanent collection
Cite this page
We encourage the use and reuse of our collection data.
Data in the title, made, maker and details fields are released under Creative Commons Zero
Descriptions and all other text content are licensed under a Creative Commons Attribution 4.0 licence
Download catalogue entry as json
Download manifest IIIF
Our records are constantly being enhanced and improved, but please note that we cannot guarantee the accuracy of any information shown on this website.