GB852934A - Electrical resistors - Google Patents

Abstract

852,934. Voltage dependent resistors. MORGAN CRUCIBLE CO. Ltd. March 25, 1959 [March 28, 1958], No. 10116/58. Class 37 A voltage dependent resistor is made by bonding together two conductive members by means of an insulating adhesive containing particles of silicon carbide. In one embodiment a strip of adhesive tape sprinkled with finely divided silicon carbide is applied to a brass disc coated with an epoxy resin, e.g. "Araldite" (Registered Trade Mark) and the assembly heated under pressure to cure the resin and to embed the particles therein. After stripping off the tape the resin coated face of a similar disc is pressed against the coated face of the first disc and heated at 150‹C. for half an hour to set the resin, any surplus being subsequently removed from the edges of the discs. The first discs of several such elements may be made simultaneously by application of a number of resin coated discs to a long strip of the adhesive tape. In an alternative method silicon carbide particles are applied directly to a disc coated with insulating adhesive or the particles are mixed into the adhesive prior to its application to the disc. Another coated or uncoated disc is then pressed against the coating and the assembly baked to cure the resin. The ultimate spacing of the discs is determined by the size of the silicon carbide particles which under pressure are formed into a single particle layer.