Power-Feed System for the Newfoundland-Nova Scotia Link

The operating power for the submerged repeaters of the ClarenvilleSydney Mines link is derived from a constant current supplied over the central conductor from power equipments located at the two terminal stations. In order to protect the electron tubes in the repeaters the current must be closely maintained at the design value, irrespective of changes in the mains supply voltage or ground potential differences between the two ends of the link. Automatic tripping equipment must be provided to disconnect the cable supply should the current deviate beyond safe limits, but otherwise there must be a minimum of interruptions due to power-equipment and primary-source failures. Earlier British Post Office schemes have been powered by electronically controlled units feeding from one end only.J Manual change-over to standby units has been provided at the end feeding power and at the distant end -- a method which has satisfactorily met the economic requirements of short schemes. * British Post Office, t Standard Telephones and Cable Ltd. W A L K E R , 1 ) . C., and T H O M A S , J . F . l , The British Post Office Standard Submerged-Repeater System for Shallow-Water Cables (with special reference to the England-Netherlands System), Proc. I.E.E., 101, Part I, p. 190, Feb., 1954. 277