Electric power distribution system to a number of loads, particularly for motorvehicles

A four-lead bus (24) comprises two power leads (36, 38) and two signal leads (40, 42). A waveshape generator (46) periodically applies to the signal leads frames each comprising a long sync pulse (S) followed by a train of narrow signal pulses (C1, C2, C3, C4, ...), each being associated to a predetermined load. Each of the narrow pulses may be marked by pulse lengthening. A plurality of connection units, associated with respective loads, may be coupled to the bus leads by means of current-tapping needles (68, 70) and can recognize the pulse associated with their associated load for enabling the supply to load if the pulse is marked.