Abstract: A monitoring and control system controls multiple lights and monitors their operation through two-way communication over power lines. An interface is connected to receive control signals for at least one of the lights from the central computer and to transmit monitoring data concerning the lights to the central computer. The interface communicates over the power lines with light controlling and monitoring devices in the field to transmit the control signals over the power lines to the light controlling and monitoring devices and to receive the monitoring data over the power lines from the light controlling and monitoring devices.

Abstract: In an arrangement for supervising and controlling field light units (20) at an airport, a regulator provided with a monitoring unit for power supply and for monitoring the light units is arranged individually for each light unit (18,20) to regulate the light intensity of the light units and to receive information as to their operational status. In a preferred embodiment, each light unit comprises two separate light sources that can be alternately and separately connected into circuit in case of failure to either of the light sources. Each light unit is provided with an electronic unit including a regulator, monitoring unit, and modem for power supply to the light unit and for monitoring the operation of the light unit. Each light unit is individually addressable from a control central for the airport. A ground traffic control system can be integrated into the field lighting system by connecting suitable presence detectors to the system.

Abstract: The present invention relates to a method and to an arrangement for installing in a duct optical fiber cable elements, such as combined groups of optical fiber ribbon cables. In order to enable the cable element to be blown into a duct (11), an optical fiber ribbon cable body (1) that has electrical contact devices provided at one end thereof and which comprises a plurality of optical fiber ribbons (2) placed one upon the other has been held together with helically wound elastic tape (3) with successive turns of the tape mutually overlapping. The external helical cross-surface thus obtained can be acted upon by a by-passing air stream, such as to drive the cable body forwards in the duct.

Abstract: In an arrangement for supervising and controlling field light units (20) at an airport, a regulator provided with a monitoring unit for power supply and for monitoring the light units is arranged individually for each light unit (18,20) to regulate the light intensity of the light units and to receive information as to their operational status. In a preferred embodiment, each light unit comprises two separate light sources that can be alternately and separately connected into circuit in case of failure to either of the light sources. Each light unit is provided with an electronic unit including a regulator, monitoring unit, and modem for power supply to the light unit and for monitoring the operation of the light unit. Each light unit is individually addressable from a control central for the airport. A ground traffic control system can be integrated into the field lighting system by connecting suitable presence detectors to the system.

Abstract: In an arrangement for supervising and controlling field light units (20) at an airport, a regulator provided with a monitoring unit for power supply and for monitoring the light units is arranged individually for each light unit (18,20) to regulate the light intensity of the light units and to receive information as to their operational status. In a preferred embodiment, each light unit comprises two separate light sources that can be alternately and separately connected into circuit in case of failure to either of the light sources. Each light unit is provided with an electronic unit including a regulator, monitoring unit, and modem for power supply to the light unit and for monitoring the operation of the light unit. Each light unit is individually addressable from a control central for the airport. A ground traffic control system can be integrated into the field lighting system by connecting suitable presence detectors to the system.

Abstract: A field lighting network providing for individual control of the light fittings while reducing overall cable costs. A converter unit converts a supply voltage obtained from an A.C. main to a substantially constant current in a Boucherot circuit with a series resonance circuit, tuned to the main frequency. The converter unit includes a Boucherot circuit having a series resonance circuit, substantially tuned on the main frequency, and an additional inductance in series with a load connected to the converter unit. A regulator unit supplied with current couples to each fitting or group of fittings for individual regulation of the current passing through the respective lamp or lamps. Each regulator unit is disposed to receive control information on the power cable.

Abstract: A multi-electrode welding apparatus is provided which includes a torch body and a least two electrodes, preferably of the non-consumable type, which are adjustably mounted in the torch body so as to be vertically positionable with respect to a workpiece and a nozzle mounted in the torch body. Interchangeable nozzles are provided for the electrodes, each nozzle being removably and interchangeably mounted in the torch body and adapted to be employed in conjunction with either of the electrodes so that one of the nozzles in conjunction with one electrode provides an open arc between such electrode and the workpiece, and another of the nozzles employed in conjunction with the other electrode provides a constricted arc between such electrode and the workpiece.