Abstract: A back-up power system which can accommodate a standard electrical device that is operable from an alternating current power source when alternating current is available, but is operable by a direct-current to direct-current converter when alternating current is unavailable, the converter being powered by replaceable low voltage battery charged by the alternating current source, with the loss of alternating current being sensed to cause the disconnection of the alternating current source and connection to the low-voltage replaceable battery.

Abstract: A back-up power system for a portable table lamp which accommodates a standard replaceable compact fluorescent bulb that is illuminated from an AC main power source when AC house current is available and is illuminated by a DC to DC converter when AC house current is unavailable, the converter being powered by replaceable low voltage battery located in the base of the lamp and charged by the AC source, with the loss of AC house current being sensed to cause the disconnection of the AC house current source and connection to the low voltage replaceable battery.

Abstract: A composite material of silicon carbide particles in an aluminum matrix is base coated with a layer of a nickel-boron alloy by an electroless process. The base-coated composite material is heat treated at a temperature of about 450.degree. C. to interdiffuse the base coating with the composite material. A nickel or gold top layer is electrolytically deposited over the base coat on the heat-treated composite material.