Abstract: A system is provided for improved communication and control over local power lines, which eliminates the problems caused by low impedance of the power main and the wideband noise and interference normally present there. The system provides for a means of disconnecting the local power lines from the power main by automatic switches during the brief time when communication is to take place. The system consists of a system controller and one or more information sources. The system controller activates the automatic switches as required and periodically initiates communication and control over the local power lines, and the information sources transmit data to the system controller under its command. A low-cost, efficient power arrangement for the system controller is also provided which utilizes a current source and a set of loads connected in series, each load optionally having an automatic shunt for turning it on or off.