Abstract: A power device such as a forward converter employing a main switch in series with a power transformer coupling an input, primary circuit and an output, secondary circuit has its transformer reset from a reset capacitor that is switched. Switching of the reset capacitor is effected by a reset switch, preferably a MOSFET, the control electrode of which is driven from a reset winding on the power transformer. Current flow between the reset capacitor and the primary winding resets the transformer. The capacitor can be chosen such that flux density in the transformer core is substantially symmetrical about zero. Leakage and magnetizing conductance energy is recycled. Large spikes are not produced across the main switch.

Abstract: A converter topology that eliminates reverse recovery losses in its output rectifying semiconductor devices employs an AC injection voltage source in series with a power transformer primary winding. Input semiconductor switches in the converter's primary circuit are controlled to provide in the power transformer secondary a voltage across the winding or windings in a first direction forward biasing one of the output rectifying devices followed by a lower level reverse biasing voltage produced by the injection voltage. This lower level voltage across the secondary turns off the previously conducting rectifier device and drives carriers out of its semiconductor junction or junctions to eliminate reverse recovery losses occurring when the secondary applies a higher level reverse bias across the non-conducting rectifier device.

Abstract: Methods and apparatus for gathering image information from nanostructures includes a composite waveguide of conductive nanoparticles in a dielectric medium. The waveguide is irradiated with preferably coherent blue light to form a slow surface wave. The evanescent wave that is the “tail” of the surface wave exists outside the waveguide contiguous to its surface. The nanostructures are located to encounter the evanescent wave. The slowing of the wave that occurs in the waveguide reduces the wave's speed and wavelength sufficiently such that nanostructures can be imaged. Upon encountering the evanescent wave, the nanostructures radiate. This radiation causes a backward scattering from the structures and a forward perturbation of the wavefront of the surface wave. From the scattering and perturbation information about the physical characteristics of the nanostructures sufficient to form an image is derived.

Abstract: A multilayer structure in which all the magnetic elements have the windings edged in the inner layers and the magnetic core which surrounds the winding has the legs penetrating through the multilayer structure. The interconnection between the magnetic elements and the rest of electronic components is done through the layers of the multilayer board, horizontally and vertically through via. For higher power components special cuts are performed in the multilayer board to accommodate the body of the components which may be connected to an external heatsink. The winding arrangement in the transformer is done in a such way to minimize and even eliminate the common mode noise injected through the capacitance between primary and secondary winding. The input filter is constructed to exhibit a differential and a common mode impedance.

Abstract: A neurocomputer (50) comprises n oscillating processing elements (60A, 60B, 60C, 60D and 60E) that communicate through a common medium (70) so that there are required only n connective junctions (80A, 80B, 80C, 80D and 80E). A rhythmic external forcing input (90) modulates the oscillatory frequency of the medium (70) which, in turn, is imparted to the n oscillators (60A, 60B, 60C, 60D and 60E). Any two oscillators oscillating at different frequencies may communicate provided that input's power spectrum includes the frequency equal to the difference between the frequencies of the two oscillators in question. Thus, selective communication, or dynamic connectivity, between different neurocomputer oscillators occurs due to the frequency modulation of the medium (70) by external forcing.

Abstract: A new steering logic based on a mixed weighted two-norm and least squares optimization solution overcomes a deficiency of being trapped in the momentum saturation singularities. The new steering logic utilizes an additional weighting matrix, W, in conjunction with deterministic dither signals in a weighting matrix V. The new steering logic also provides a simple means of avoiding troublesome, internal elliptic singularities which are commonly encountered by most other pseudoinverse-based steering logic. Various CMG systems, such as a typical pyramid array of four single-gimbal CMGs, two and three parallel single-gimbal CMG configurations, and four parallel double-gimbal CMGs of the International Space Station are described as illustrative embodiments demonstrating the simplicity and effectiveness of the new steering logic.

Abstract: A power supply circuit comprising an active power factor correction circuit. The active power factor correction circuit comprises a controller for controlling both the power factor correction and the inrush current control circuit. The inrush control circuit comprises at least one insulated gate bipolar transistor (IGBT) connectable to the controller.

Abstract: The invention discloses improved structures of light-processing (e.g. light-emitting and light-absorbing/sensing) devices, in particular Vertical Cavity Surface Emitting Lasers (VCSELs), such as may find use in telecommunications applications. The disclosed VSCAL devices and production methods provide for an active region having a quantum well structure grown on GaAs-containing substrates, thus providing processing compatibility for light having wavelength in the range 1.0 to 1.6 ?m. The active region structure combines strain-compensating barriers with different band alignments in the quantum wells to achieve a long emission wavelength while at the same time decreasing the strain in the structure. The improved functioning of the devices disclosed results from building them with multicomponent alloy layers having a large number of constituents.

Abstract: A method and apparatus for detecting electromigration at its outset includes a pair of conductive traces deposited on a substrate in an integrated circuit. A multiplicity of conductors are connected along the length of the traces. Current is passed through the traces and the resistances of the traces from one conductor connection to the next are continually monitored by observing the voltage drop from one conductor to the next. The connection of the conductors to the traces may be less than one micrometer apart. When resistance changes as a result of the onset of electromigration, the exact location can be determined and studied in optical or scanning electron micrographs.

Abstract: Water may be purified and treated to kill and/or remove various harmful contaminants and microorganisms with a method and system including ozone treatment and oxygenation. In the present system and method, the ozone treatment and oxygenation process is carried out in the chamber of one canister and includes one or two further canisters, either a pre-filtration canister that contains a filter for removing large particulates that might interfere with the ozone treatment and oxygenation process, or a post-filtration canister that contains a filter for removing smaller particulates downstream, or both. The system is versatile in that one or the other of the filtration canisters can be eliminated. To limit the expense of manufacturing the system, the exterior of the canisters are identically molded and the bottom caps of the canisters are integrally molded to the body of the canisters, also eliminating one possible leakage point.

Abstract: A method for determining the Coefficient of Thermal Expansion of a specimen. The specimen is placed in the tester and a tensile force is applied to the specimen. The specimen is equilibrated at a first temperature and then elongated. After reaching a desired elongation, the specimen is equilibrated at another temperature. The tensile force on the specimen is changed to a predetermined value or until the specimen fails. A force-displacement curve is generated from the stressed specimen. The force-displacement curve is converted into a stress-strain response, from which the Coefficient of Thermal Expansion is determined.

Abstract: Semiconductor nitride layers are produced using a corona discharge supersonic free-jet source producing an activated nitrogen molecule beam impacting a semiconductor substrate in the presence of a group III metal or impacting an oxide layer on a semiconductor substrate. The activated nitrogen molecules are of the form N2A3&Sgr;u+. Apparatus for producing the nitride layer on the substrate includes the corona discharge free-jet source, a skimmer to collimate the N2 beam and succeeding stages interconnected by collimators and evacuated to draw off background gases.

Abstract: A hard machining process uses a cylindrical tool (21) of ceramic or other hard machining material of comparatively low cost that provides a circular cutting edge to be engaged in cutting relation with hardened workpiece (20) to be machined. As tool cutting edge wear occurs, the tool (21) is rotated through a small angle to bring into contact with the workpiece (20) a fresh portion of the cutting edge. It is not necessary to rotate that tool (21) sufficiently to effect replacement of the entire cutting edge portion in engagement with the tool. Sufficient angular movement of the tool is made to replace that of the cutting edge that has the greatest effect on the finish of the machined workpiece (20), which is the cutting location where the removed chip is thinnest.

Abstract: An improved freeze/thaw characteristic is achieved in concrete by substituting crumb rubber for entrained air. The percent by volume of entrained air for concrete prescribed for a given set of freeze/thaw conditions is first determined then a predetermined quantity of crumb rubber is introduced into the mix in dependence on the percent of air entrained in the prescribed air entrained concrete.

Abstract: A front wheel of a scooter is pivotally mounted to a frame and includes an upwardly extending shaft supporting a handlebar for steering the scooter. A footpad or peg or pedal, mounted on a spring returned lever, is interconnected with the rear wheel through a gear mechanism supported by the frame. By pumping the footpad, rotation of the rear wheel and forward motion of the scooter occurs. The gear mechanism includes a first gear or sprocket mounted for rotation about the arms of rotation of the rear wheel. A further sprocket coaxially mounted is linked via a drive-chain to a sprocket on an offset shaft. A further sprocket on the offset shaft drives a final, drive sprocket via a further chain. And the final sprocket drives the rear wheel through a one way clutch. Depression of the footpad, peg or pedal moves a rack-like bar longitudinally. The bar is in engagement with and drives the first gear or sprocket. The bar may carry drive-chain cross-members or pins that engage the teeth of the first sprocket.

Abstract: An ultrasonic path guidance system and method for the visually impaired uses an array of ultrasound transmitters that are directional and aimed at distinct locations forward of the user. The transmitters are positioned on the torso of the individual user and one or more receivers detect echoes from obstacles upon which the transmitted ultrasound sound impinges. Audible tone is generated each time an echo is received. The tone's frequency is dependent on which transmitter transmitted the original ultrasound pulse that resulted in the detected echo. This gives an easy to understand indication of the location of detected obstacles. The elapsed time from emission of an ultrasound pulse to reception of its echo is used to arrive at the distance to the obstacle.

Abstract: An extrusion system controller monitors the movement of an extrudate using a motion detector. Upon detection that the extrudate is no longer moving along its path of movement at the appropriate speed, the controller causes power interruption to the extrusion system by a controlled power switching device. A dimensional anomaly detected by a gauge can cause the controller to effect power interruption as well, when the anomaly lies outside a range of correctable dimensions or when the anomaly does not respond to corrective action by the controller. In the event that a cutter is used on the extrusion line, a detector that may be a photodetector senses that the extrudate is being severed regularly. In the absence of regular severance of the extrudate, the controller effects a power interruption. By use of these techniques, the extrusion line can run entirely unattended.