Abstract: Lightning strike protection for an aircraft or part of an aircraft is provided by mounting metal (aluminium) rods adjacent but spaced from the inner surface of the aircraft wall. The rods are provided with ball joints from which extensions through the wall stand proud of the aircraft outer surface and within the material of static dischargers. The rods are coupled to bus bar which run the length of the aircraft in turn are coupled to lightning strike dischargers (again in the form of metal rods carried on but spaced from the wall of an aircraft and having extensions which pass through the aircraft wall). The application of the lightning strike protection system to radomes, antennas, pitot tubes carbon fiber reinforced plastics structures is discussed, in the former two cases metal rods being provided to extend in the null field of a device within the radome or the antenna.

Abstract: An electronic ballast for discharge lamps comprises an open loop configuration of an impedance converter first stage and an inverter second stage linked by a limiting control stage. The impedance converter stage presents its load, passive or active, as input resistance. It draws a continuous current, through large RFI/EMI suppressing input inductors, which is switched discontinuously through a tank circuit using an energy transfer relationship based on the switch on-time and the inductance and capacitance of the tank circuit. The impedance converter stage supplies unregulated power to the inverter stage which operates stably at a fixed frequency. If an imbalance such as an overcurrent condition or an overvoltage condition develops in the system, the limiting control stage temporarily preempts the converter switching until stability is reestablished.

Abstract: A method and apparatus for making continuous lengths of thermoplastics material fibers reinforced laminates by arranging layers of fibers reinforcement impregnated with a thermoplastics material in alignment with and between outer sheets of another material to form a stack and passing the stack through a tool having two opposing platens, one of which is movable relative to the other, and operating the tool so as to compress the stack and form a laminate. The stack is passed from entry to exit of the tool in steps, the extent of each of which is substantially less than the length of the tool such that each area of the stack is subjected to repeated compressions by the tool is passing therethrough. A recess is formed in one platen, which is adapted to receive a land formed on the other platen.

Abstract: A scanning control system is disclosed for remotely sensing or monitoring a predetermined condition or state, such as the presence of a fire, by means of one or a multiplicity of detecting stations at one or a multiplicity of locations with each detecting station providing a positive indication of the location of each predetermined condition sensed. A scanning or control panel is electrically connected with the detecting stations by means of four wires extending from the panel regardless of the number of detecting stations utilized in the system.