Abstract: An electricity supply network has plural switching and transformer stations connected together by cables. Each cable has an inner conductor and an outer sheath connected to housings of the stations. A communication system has plural transducers coupled to the cables at the stations. Each of the transducers is located on a side of its respective cable remote from a sheath connection of the respective cable to its station housing. Each transducer is coupled to both the sheath and the conductor of its respective cable.

Abstract: A power supply system for premises (12') has a meter (20) which stores tariff information (rates and times) received via mains signalling from a controller (13). An outlet (33) has control means (40) responsive to the tariff information stored in the meter. The control means may be programmable simply to allow the outlet to supply power only during low tariff rated periods, or to utilize more elaborate criteria, such as maintaining the supply of power either for a predetermined time regardless of tariff changes once the outlet has been turned on or until the device fed by the outlet has completed its operating cycle (as determined by the current drawn falling to zero), or effecting an inverse control between the tariff rate at which the outlet may be turned on and the time elapsed since it was last turned on.

Abstract: A remote electricity metering system utilizes a central station (LC) to communicate with meters (U1-U13) over the mains (10-14), with messages to remote meters being relayed by intermediate meters and the route of a message being determined by the central station. The present invention provides alarm signalling whereby the meters can communicate directly with the central station. Each meter can generate a respective combination of alarm frequencies, preferably sequentially and inside the frequency band used for normal messaging, and the local controller monitors the mains for those frequencies. An error detecting and/or correcting code can be used for the alarm frequency combinations. The central station polls the meter or meters sending the alarm. The meters are microprocessor based, with the normal message signals and the alarm frequencies being synthesized from a sequence of digital values by a D/A converter.

Abstract: An apparatus and method for remotely determining the phase of a single phase load on a multi-phase power distribution system, including powerline communications and repeaters. The phase determination being based upon comparison of message receipt times.