Abstract: A power-distribution network for the energization of a multiplicity of loads comprises a two-conductor trunk extending from a DC supply, a plurality of parallel primary branches connected to the trunk via respective first overload-responsive circuit breakers, and a plurality of parallel secondary branches connected to each primary branch via respective second overload-responsive circuit breakers. Each secondary branch terminates at one or more DC/AC converters feeding associated loads, the converter frequencies being suppressed in the supply network by filters included in the second circuit breakers. Each circuit breaker further includes at least one capacitor which, in the event of a short circuit in a parallel branch, supplies the associated loads for a time long enough to let the supply voltage substantially recover its normal value.

Abstract: To measure electrical characteristics of a line segment, a switch or some other circuit element of a time-sharing telecommunication network using pulse-amplitude modulation, a transmission path is established between two subscriber lines through the circuit element to be tested, these subscriber lines being respectively connected to a generator of a sinusoidal test signal and to a highly sensitive signal detector. The two subscriber lines are briefly closed during a single sampling interval, or during two consecutive sampling intervals separated by an intervening guard interval during which capacitively stored residual energy is dissipated, depending on the nature of the test.