Abstract: Ceramic capacitors are formed from electrodeposited ceramic dielectric layers that are provided with electrodes, stacked and fired. Contact to the electrodes is provided by each terminations and leads. As the electrodeposition process is self limiting and self heating, uniform pinhole free dielectric layers are obtained.

Abstract: An electrical contact unit comprises a flexible semiconductor, e.g. silicon, filament carrying contacts and having a shorted pn junction. The filament is mounted in a magnetic field. When light is directed on to the junction, e.g. from an optical fiber, the induced photo current flowing around the short circuit interacts with the magnetic field so as to bend the filament so as to establish connection with one or more adjacent fixed contacts.

Abstract: Powder is coated with valve-metal by rotating it in a drum 15 so that it is presented to valve-metal vapor derived by evaporation of a source of valve-metal. In the case of coating with aluminum, the vapor may be produced by directing aluminum wire 10 on to a heater 11, and oxygen or air is admitted to control agglomerate formation. Aluminum and tantalum coating are both described using electron beam evaporators.

Abstract: The vitreous material, e.g. silica, is deposited on the inner surface of the tube from a hot, intense, inductive plasma, which plasma is formed by utilization of wavelengths substantially longer than the diameter of the plasma. The process may be employed in the production of preform tubes or step or graded index optical fiber manufacture by gradually varying the contents of the vapor introduced into the plasma.

Abstract: Crystalline semiconductor material is produced in strip or sheet form by a gas process. The corresponding amorphous semiconductor is vapour deposited on to a substrate material which is subsequently removed from the amorphous semiconductor. The semiconductor is then selectively heated to induce crystallization. Devices may be fabricated on the crystalline material in tandem with the deposition and crystallization processes.

Abstract: A solid electrolytic capacitor has a porous anode body manufactured from a valve metal coated core by pressure compaction of the metal powder at 25 to 40 tons per square inch. No subsequent sintering is required by this process.

Abstract: A method of selective plating, e.g. of gold on phosphor bronze, includes the steps of printing on the phosphor-bronze a mask which defines the area to be plated, electro-painting the unmasked areas in an electrolytic bath with an epoxy-phenolic paint, stoving the material so that the epoxy coat becomes a strongly adherent and chemically resistant layer, removing the mask produced in the first step in a suitable solvent, leaving the metal to be plated bare, and electro-plating. The epoxy coating may be left in situ or removed.

Abstract: A method of manufacturing a continuous preform for an optical fibre of the type produced from glass or silica tubes or rods, the method including arranging the tubes or rods end to end in a rectilinear array, placing glass or silica sleeving tubes over the joints between the rods or tubes, and fusion sealing the joints between the rods or tubes.

Abstract: A line current detector for use in telecommunications systems to monitor line condition. The detector uses an optical or photo electric device whose input is modulated by line current. A photo transistor, electrically isolated from the line, senses the modulated output of the detector to produce a condition responsive output. The optical device is preferably a liquid crystal device. The output sensor is isolated from the line.

Abstract: An electro-plating method and apparatus therefor in which a discrete area of plating, such as a stripe about an elongated workpiece can be deposited without the use of separate masking. A plating solution having a depth equal to the length of the stripe desired is floated over a denser, inert, immiscible liquid (such as a liquid fluorocarbon). Workpieces are attached to a carrier which is electrically energized as cathodes and which are positioned vertically such that the area to receive the plated stripe is within the layer of plating solution, the workpieces projecting above the plating solution layer and below into the inert liquid as necessary. Pump weir and sump arrangements provide for maintenance of the plating solution and inert liquid levels and an anode is separately provided.