Transmitting electrical power and communication signals

摘要

A system for transmitting electrical power and communication signals, comprises a transmission line (3); a source (5) of electrical power for supplying electrical power to the transmission line; first communication means (10) for supplying communication signals to the transmission line; power extraction means (4, 6, 7) for extracting and using electrical power from the transmission line; second communication means (11) for receiving communication signals from the transmission line; and control means (8, 9) for controlling operation of the system in such a way that, in use of the system, the power source supplies electrical power to the transmission line for respective periods of time which are different from respective periods of time in which the first communication means supplies communication signals to the transmission line.