Abstract: A printed-circuit board designed to energize a multiplicity of integrated chips or other modular units comprises on a first face two closely spaced main conductor strips, respectively connected to an ungrounded and a grounded terminal of a d-c source, extending along an edge thereof, together with a number of ancillary ground conductors paralleling these strips at substantially equispaced locations. The second face carries a multiplicity of branch lines perpendicular to the strips, each line consisting of two closely spaced leads respectively joined to the ungrounded strip and to the main and ancillary ground conductors through connectors traversing the board. The leads of each branch line are bridged by several storage capacitors and are so spaced apart and dimensioned as to provide a line inductance low enough to make the resonance frequency of the line substantially higher than the operating frequency of the associated loads.

Abstract: Two power transistors operating in push-pull, connected in series with respective halves of a transformer primary across a d-c source, are alternately rendered conductive by driving pulses generated during fractions of corresponding half-cycles of a square-wave oscillator. Two integrating networks, connected across these primary halves or across resistors in series therewith, work into a comparator whose output signal, reflecting a dissymmetry between the transistor currents, unbalances the square-wave oscillator to vary the relative width of the two sets of driving pulses until the dissymmetry substantially disappears.

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.