Abstract: A composite system capable of protecting a substrate from a jet fire including a lower layer of an active fire protective material and an upper layer of a fire protective material. The upper layer forms an open cell matrix when exposed to a jet fire to permit passage of gasses from the lower layer to ambient. The upper layer comprises a fill of refractory material and protects the system during initial exposure to a hyperthermal condition. The upper layer swells on exposure to hyperthermal conditions, but swells less than the lower layer.

Abstract: A power supply operable from power mains voltages generally within two voltage ranges according to which the power supply automatically switches between a full wave and a voltage doubler. Furthermore, the power supply provides automatic mode selection on a cycle-by-cycle basis, sensing the mains signal during an initial portion of the mains input cycle and causing the power supply to select a mode of operation during that cycle. Thus, the present invention provides rapid response to changing mains voltages. Moreover, the voltage doubler mode is inhibited during the initial power up period, providing a margin of safety when initially energized or when connected to rapidly changing mains voltages.