Abstract: An electronically controlled power supply rail provided with only three conductors, such a rail enables a number n of utilization channels to be supplied, and this to be independently of one another, comprising a transmitter positioned at the end of the rail which emits, as a function of the instructions which are given, a control signal which is transmitted by one of the three conductors to a plurality of receivers associated with each of the channels, each receiver couverting said control signal into a triggering signal capable of selectively actuating a power switching-member, thus causing a supply to be applied to the utilization channel selected.