Abstract: The cells of a static random access memory have a diagonal of `dog leg` structural layout. This permits the use of straight word lines of low impedance and hence of low time constant. Advantageously the work lines are of polysilicon thus permitting a compact design.

Abstract: Printed circuit manufacture may employ a plated palladium-nickel alloy layer as an etch resist and plating finish. Prior to the use of palladium-nickel, tin-lead was used as the etch resist and plating finish. The palladium-nickel layer is generally superior to the corresponding tin-lead layer except for solderability. To improve the solderability of at least these areas of the palladium-nickel to which elements are to be soldered, a layer of copper is deposited thereon. If desired, the solderability of the copper may be preserved by coating it with, for example, a tin-lead layer.

Abstract: A telephone exchange conference circuit for three-party conferences, receives the PCM bytes from the conferees in a FIFO store (4), and checks the bytes in a processor (1) to find the one for the loudest outgoing speech. This is then sent to another FIFO store (5) for transmission to the other conferees. This loudest speech sample is sent to all conferees other than the one which originated that sample: he gets a silent code.The system has two time slots per conferee, one for "talk" and for "listen".

Abstract: A temperature compensated crystal oscillator in which the base emitter voltage of transistors in an integrated circuit is used to provide substantially linearly temperature sensitive outputs which are employed to generate a series of polynomial functions of Chebyshev-like form which are summed and used to control a varicap diode in the oscillator feedback path.

Abstract: An optical fibre pulling tower is made of tubular modular substructures (5) of synthetic granite mounted one on top of the other by means of joining plates (6) cast in situ. A baseplate (13) sits on a concrete raft (14) and is adjustable to be exactly upright.

Abstract: All the layers of the anode foil of an electrolytic capacitor roll (5) are cold welded to a piece of tabbing (8) using radiussed weld tooling (10, 12, 13) which bends the foil layers in the course of the welding operation so as to enable a good weld to be effected. The cathode foil layers are welded to their piece of tabbing in the same way. Optionally the roll may be partially flattened at the time the welds are made.

Abstract: A ceramic chip capacitor comprises electrically conductive layers extending alternately to two opposing edges of a rectangular ceramic body. The other two edges are provided with electrical terminations. The edges to which the conductive layers extend are partially covered with fusible metallic films which connect the layers to respective terminations. The fusible films isolate the capacitor from associated circuitry if the capacitor fails and effects an internal short circuit.