Abstract: In an electrical power system for a residential building, a multi-conductor cable supplies power to loads in the residential building from a power supply. A net current returning from loads to the power supply via alternative conductive paths different from the neutral conductor in the cable creates a magnetic field in the vicinity of and inside of the residential building. A net current control device, including a ferromagnetic core, is attached to the multi-conductor cable in order to increase the impedance of the alternate conductive paths to the net current and to increase the net current flowing along the neutral conductor. Various modifications of the net current control device are disclosed.

Abstract: A protective relay for detecting power arcing faults on a low-voltage spot network. The protective relay can monitor the voltage difference between each phase conductor, the voltage difference between each phase conductor and the neutral conductor, or the current on each phase conductor. Using one of these three sets of values, the protective relay first filters the input signal so that only frequencies indicative of a power arcing fault on the low-voltage spot network are analyzed. The signals passed by the filter are amplified, rectified, and averaged and the peak of each signal detected. If the peak has a duration longer than a predetermined value, a fault indication is provided.

Abstract: A fabric to have a latex coating of controlled thickness applied to its upper surface moves toward a drying oven. The lower surface of the moving fabric contacts a supporting bedplate. A latex coating is applied to the upper surface of the moving carpet across the width of the carpet. The moving carpet with the latex coating travels underneath a nip roll. A flexible nip blade is positioned underneath the nip roll so that the edge of the nip blade extends beyond the bottom dead center of the nip roll in the direction of the drying oven. Both the nip roll and the nip blade extend across the width of the moving carpet.

Abstract: A circuit arrangement is disclosed for sensing a presence or absence of a low-level output signal which may be used for detecting a change of resistance in a magnetic bubble detector. The circuit operates in a D.C. coupling mode whereby the low-level signals are directly coupled into a sense amplifier, which is preceded by the circuit above-mentioned. The circuit, which comprises a modified current mirror, is used as a resistance transducer which converts a change of resistance (.DELTA.R) into a direct change of voltage (.DELTA.E). The change of voltage provides an indication of the presence of, for example, a magnetic bubble.

Abstract: An improved electrical cable coupler incorporates rotatable protective covers on its plug and socket members to automatically protect the plug and socket contacts against contamination when the plug and socket members are disconnected and to allow the contacts to be electrically engaged when the plug and socket members are connected together. Each protective cover includes one or more openings which correspond in number and location to the electrical contacts on the plug and socket members. Each cover is rotatable between a protective position in which its openings are out of alignment with the respective contacts to provide protection against contamination and an operative position in which the openings are aligned with the respective contacts to expose the contacts for electrical engagement.