POWER LINE COMMUNICATION SYSTEM

A power supply circuit includes a number N, N 2, of parallel connected, cyclically switched electronic converters having outputs connected to a common output terminal; and a controller providing switching pulse signals switching the converters with a switching frequency that is the same for all converters; load circuits connected to the output terminal; a PLC transmitter modulating an output current from the output terminal; and a PLC receiver in each load circuit, the controller switching the converters with interleaved switching pulse signals; the PLC transmitter modulating the output current by switching the controller between at least two modes of operation that differ in phase relations and/or pulse shapes of the switching pulse signals, changing a ripple frequency spectrum of the output current such that a suppression amount of a predetermined frequency component is changed depending upon the mode of operation; and the PLC receiver detects the predetermined frequency component.