| << Viewing Record 993 of 1323 >> View : Light Box | List View | Image List | Detailed |
|
ID number: BIRRC-P0009 Institution: Research and Cultural Collections Named collection: Historic Physics Collection Artist / Maker: Bouron (as indicated on original record card) Title / Object name: Post Office Relay Object type: Electrical instrument Materials: Brass case with glass top (removed in photos) on wooden base Measurements: Diameter of base 13 cm, of brass case 7.5 cm, height 12 cm |
|
|
Such relays were used at intervals along long-distance telegraph lines to boost signals that would otherwise not be strong enough to complete the distance. The incoming electrical pulse activates an electromagnet that operates a set of contacts, which then generate a new signal from a fresh battery. In this case the action, seen through the glass window, makes one contact just before breaking another. Inscriptions / Translations: On brass plate: GPO 45. Also engraved internally with a crown above 45 |
|
2 Related Media Items
|
BIRRC-P0009a.jpg |
BIRRC-P0009b.jpg |
| << Viewing Record 993 of 1323 >> |