Abstract: A digitally-controlled cycloconverter converts a multiple-phase power signal of variable frequency into a single-phase or multiple-phase signal of a lower selected frequency. The cosinusoidal algorithm is utilized to determine the firing delay times, with the analog reference wave used in that algorithm being created from a digitized hardware table. The cosinusoidal algorithm is further simplified by defining the relationship between the analog reference wave and the cosinusoidal timing waves in terms of a two-part piecewise linear relationship which is incorporated into a digital algorithm. The digital algorithm is implemented on a system employing a high-power microprocessor having hardware multiplication and division capability, allowing the algorithm to be used with supply voltages having frequencies about those previously used for cycloconversion. The control logic involved with the firing of a series of thyristors is simplified by utilizing pulse transformers.

Abstract: Detergent bars (soap or non-soap) are stamped or imprinted using a die or dies having a modulus of elasticity in the range 5.times.10.sup.5 to 1.times.10.sup.7 Nm.sup.-2. This gives reduced adhesion of detergent to die, reduced die-blocking and consequently reduced marring of bars. Preferably each such die has a facing layer of elastomer so as to achieve the desired low modulus of elasticity which preferably is distinctly less than that of the detergent.

Abstract: An opto-electronic device, comprising an optical waveguide and means for imposing an electrical field in a direction transverse to the waveguide, is designed such that the spatial spread of the electrical field is very small. The electrical field overlies the region of peak amplitude of the profile of optical radiation in the waveguide. Constructed principally out of semiconductor materials made from elements selected from the III and V groups of the Periodic Table, the device lends itself to monolithic integration in optical communications systems.

Abstract: An optical waveguide device, suitable for coupling to optical fibers, provides a combination of narrow optical confinement and small changes in refractive index along a first axis, with broad optical confinement and large changes in refractive index along a second, perpendicular axis. A rib waveguide in which a single transverse mode beam can propagate, comprises a thin guiding layer 2 sandwiched between a pair of relatively thick confining layers 1, 3 of refractive index only slightly less than that of the guiding layer 2. The rib is etched through both the upper confining layer 3 and the guiding layer 2 and is exposed at its sides and top to air.

Abstract: A method of sensing the optical deflection function of an approximately cylindrical object, such as an optical fibre preform, comprises illuminating the object with collimated light; focusing the transmitted light so that in the focal plane the distance of the light from the optical axis is linearly proportional to the angle through which light has been deviated by the object; optically modulating the focused light so that a property of the light varies as a function of said distance, and calculating the deflection function from the modulated light. The modulations may be spatial or temporal. The refractive index profile can also be calculated.

Abstract: Buffer storage apparatus is disclosed for use with a semiconductor wafer processing system having plurality of processing stations positioned along a conveyor structure and in which allowance must be made for different processing rates at different stations, the buffer storage apparatus including a first buffer storage station positioned between a first and a second processing station for temporarily holding wafers received from the first processing station and then conveying them to the second processing station, and a second buffer station positioned between the second processing station and the third processing station and including means for conveying a wafer received from the second processing station to the third processing station or for temporarily holding it.