Abstract: An electrical fuselink having improved surge-resistant characteristics comprises a fuse element (1) disposed in an electrically insulating enclosure (4) having all or part of the air-space within the enclosure filled with a microporous or microcellular insulating material (2) which has low intrinsic thermal conductivity and cavities or cells of a size less than the average inter-molecular collision distance of the gas, normally air, occupying its cavities or cells. The fuse element is connected between electrical leads (3) which project from the enclosure for connecting the fuselink in an electrical circuit.

Abstract: An electrical component comprising a temperature responsive device including an electrically conducting member (1) of spring temper in contact with a thin insulating coating (3) of a substance which decomposes on being subject to an elevated temperature thereby allowing the conducting member (1) to effect a short circuiting operation. Suitably the conducting member (1) is coated with a thin layer of polyurethane varnish which vaporizes at the elevated temperature, and the conducting member (1) is arranged to engage contacts (5,5) under spring tension. In one embodiment the conducting member (1) is a wire of phosphor bronze or beryllium copper formed as a loop (2) with spring arms, the loop (2) being positioned on a pin 4 centrally disposed between spaced contacts (5) engaged by the arms under spring tension.

Abstract: A subminiature fuse comprises a fuse element (1) disposed within a glass sleeve (2) and connected at opposite ends to tail wires (3) which are formed with collars (4) fusion bonded to the wires (3). The collars are positioned within opposite ends of the sleeve (2) which are fused about the collars (4) to effect hermetic sealing. The collars may be glass beads disposed about the wires (4) or they may be of metal suitably having a coefficient of expansion matching that of the glass sleeve (2).