Abstract: The invention is a circuit for eliminating or reducing unwanted components from an optical output signal. The circuit employs a photodetector for converting a portion of the output signal to an electrical signal, and a feedback loop which passes only the second harmonic band or the frequency difference band for combining with the input biasing signal.

Abstract: For use with a rack having a carrier backplane and capable of receiving modular circuit packs therein to be coupled to the carrier backplane, a circuit pack cable adapter that allows the modular circuit packs additionally to process signals originating from other than the carrier backplane, and a method of operation thereof. The circuit pack cable adapter includes: (1) a cable interface proximate a rear end of the circuit pack cable adapter and (2) an extension cable, coupled to the cable interface and couplable via the cable interface to a main cable passing through an aperture in the carrier backplane proximate the rear end, the extension cable deployable from a front end of the circuit pack cable adapter to at least one of the modular circuit packs to allow the modular circuit packs additionally to process signals originating from the main cable.

Abstract: A control system comprising an electrical circuit that produces distortion where the electrical circuit has a frequency band of operation. A pilot modulated carrier signal is generated and is cause to traverse across the frequency band of operation of the electrical circuit. Information obtained from the traversing pilot modulated carrier signal when it is determined that there is no interference between any signal applied to or generated by the electrical circuit. The information is used by the control system to substantially cancel the distortion.

Abstract: An integrated circuit output buffer has an improved tolerance to voltage levels that are greater than the power supply voltage level at which the IC is designed to operate. A first transmission gate transistor (110), typically p-channel, is connected between an output conductor (101) and a resistor (108) at a given node (114). The node is also connected to the gate of a second transmission gate transistor (105), typically also p-channel. The resistor pulls the given node towards a power supply voltage level (e.g., ground), so that the second transmission gate transistor conducts in normal operation. To prevent the node from reaching ground, at least one diode-like voltage-dropping device (201, 202) is connected in series with the resistor.

Abstract: For use with a power converter having a switching circuit coupled to a primary winding of a transformer and a rectifier coupled to a secondary winding of the transformer, the switching circuit exhibiting switching losses and the rectifier inducing reverse recovery currents in the converter, a snubber circuit and a method of reducing the switching losses and reverse recovery currents.

Abstract: A method and apparatus for assisting in the performance of maintenance, repair and emergency services. An integrated field support system is connectable to a customer support center. The integrated field support system comprises a portable platform (a computer), a group of peripheral devices, and a communications interface for accessing the customer support center. The field system allows field personnel to receive displays of documentation, graphics and other pictorial displays, and to issue commands orally for interpretation by a speech recognition unit. The connection to the customer support center provides personnel in that center with all data available to the field personnel and vice versa. Advantageously, this method and apparatus allow field personnel to receive the information they need to perform their tasks in an optimal fashion.

Abstract: Determining the location of an ESD event is achieved through the use of an envelope detector or absolute value comparator which identifies the arrival of an electromagnetic waveform generated by an ESD event at each of a plurality of antennas. Arrival times are compared to determine the location of the ESD event. A plurality of N antennas are employed, and each antenna is coupled to a corresponding envelope detector, threshold discriminator, switch, and register. The output of a clock is coupled to the switches, and a microprocessor is coupled to the registers. When an antenna receives a waveform corresponding to ESD, the envelope detector extracts an envelope signal related to the envelope of the waveform and couples the envelope signal to the threshold discriminator. When the envelope signal has a value above a specified threshold, the threshold discriminator sends a signal to latch the current count of the clock into the corresponding register.

Abstract: A high frequency electrical connector includes a number of input terminals and output terminals that are interconnected by three metallic lead frames mounted on a dielectric spring block. The lead frames comprise flat elongated conductors, each terminating in a spring contact at one end and an insulation displacement connector at the other end. The lead frames are mounted on top of each other and their conductors are generally parallel and close to each other. Selected conductors of the lead frames crossover each other when they are mounted on the spring block but are prevented from making contact with each other at the crossover point. One pair of adjacent conductors are spaced a first distance from each other up to the crossover point, and a second, greater distance from each other beyond the crossover point for a portion of their lengths. The conductors of the one pair cross each other at a second crossover point.

Abstract: Applicant has discovered that the dielectric constant of Ta.sub.2 O.sub.5 can be significantly enhanced by the addition of small quantities of TiO.sub.2. Specifically, if Ta.sub.2 O.sub.5 is doped with more than about 3 mole percent of TiO.sub.2 the doped material will have a dielectric constant higher than the undoped material. For example, at a ratio of 0.92 Ta.sub.2 O.sub.5 :0.08TiO.sub.2, the dielectric constant is enhanced by a factor of more than three. Because both Ta and Ti are compatible with current microelectronics processing, the new dielectric can be used to make capacitors of reduced size with but minor modifications of conventional processes.

Abstract: A system which makes use of existing coax wiring to provide video-on-demand to individual subscribers. IP addressable, bi-directional video switches are used to replace traditional set-top cable boxes. The video switches are controlled by a network server which communicates with them over the existing coax wiring by using one of the frequencies previously used to transmit a VHF channel. The network server also controls video servers and a video head end, and it interfaces with the coax by means of a head end IP tap. Consequently, the network server can receive the subscriber's request for particular video programming, and it can order a video server to provide such programming to the subscriber, coordinating the programming, any desired frequency shifting, and the selection of the frequency on which the programming should be transmitted by the video head end and received by the subscriber's video switch.

Abstract: A protection device for an electrical circuit comprises a housing assembly, a fuse support structure that is comprised of a conductive material and that can be coupled to the housing assembly, a main fuse that can be mounted to the fuse support structure to receive a flow of current therefrom and a trip fuse mechanically mounted to the main fuse by electrical contacts. The electrical contacts not only secure the trip fuse to the main fuse, but also provide a conductive path across the main fuse and through the trip fuse. In some embodiments, a momentary switch may be coupled to the trip fuse. In such instances, the trip fuse is configured to activate the momentary switch when a predetermined excessive current flows through the trip fuse and may be electrically connected to a current indicator that indicates when the excessive current flows through the trip fuse.

Abstract: A parallel ring network is restorable upon sensing a failure of a transmission media. A central transmitter is coupled to one end of a first transmission medium. A central receiver is coupled to one end of a second transmission medium. A central sensor senses a transmission media failure centrally and provides a central alarm. In response to the central alarm, the central receiver is coupled to another end of the first transmission medium and the central transmitter is coupled to another end of the second transmission medium. At least one local station has a local receiver, a local transmitter, a local sensor for sensing a transmission media failure locally and providing a local alarm, and a local switch. In response to the local alarm, the local switch moves from a first position to a second position. When the local switch is in the first position, the local transmitter is coupled to the second transmission medium and the local receiver is coupled to the first transmission medium.

Abstract: The dynamic gain control system includes a pump source providing pump light. The dynamic gain control system measures a certain portion of the input pump light into the optical amplifier and measures a certain portion of the output pump light from the optical amplifier. The dynamic gain control determines the pump light loss based on the input pump light and output pump light measurements. Based on the pump light loss, the dynamic gain control system maintains the pump light loss relatively constant (for example 0.1 dB) independent of the number of input channels and their relative powers (for example, input channel powers of +50 dBm to 10 dBm) by providing feedback to control the output pump light. In doing so, the dynamic gain control system maintains the inversion level of the optical amplifier. A relatively constant inversion level corresponds to only small variations in the gains of the input channels (multi-channel gain) as a result of changes in the input channels to the optical amplifier.

Abstract: A system for reducing bandwidth of video signals. Ordinarily, an NTSC (National Television Standards Committee) video signal has (a) a bandwidth of 6.0 MHz, (b) chrominance and luminance carriers separated by about 3.58 MHz, and (c) an audio carrier located at the upper end of the 6.0 MHz bandwidth. The invention reduces the separation between chrominance and luminance carriers to about 2.15 MHz, and decreases the bandwidth to about 4.0 MHz. In addition, the invention moves the audio carrier outside the 4.0-MHz bandwidth. The invention allows multiple channels, of 4.0 MHz bandwidth each, to be placed adjacent each other in a cable television spectrum, and the audio signals of the channels to be placed together, at the upper end of the spectrum, outside the range allocated to the video information. A larger number of channels is obtained than would otherwise be available, because the upper end of the spectrum is not suitable for carrying video information, but will handle audio information.

Abstract: In a power converter having a power train that includes a power switch and a rectifier for conducting forward currents from the power switch, a circuit for, and method of, moderating a peak reverse recovery current of the rectifier and a power converter employing the circuit or the method. The circuit includes: (1) a snubber circuit coupled to the rectifier and including a snubber inductor, a snubber capacitor and an auxiliary diode, the snubber inductor reducing the peak reverse recovery current of the rectifier and the snubber capacitor recovering energy stored in the snubber inductor and (2) an auxiliary switch, coupled in parallel with the power switch, that is activated when the power switch is transitioned from a conducting state to a non-conducting state to charge the snubber capacitor.

Abstract: A low-complexity method and apparatus for performing signal decomposition in a low bit-rate WI speech encoder. A time-ordered sequence of sets of time-domain parameters is generated based on samples of a speech signal to be coded, each set of time-domain parameters corresponding to a waveform characterizing the speech signal. A cross correlation is then performed between two or more of said sets of time-domain parameters to produce a set of signals which represents relatively high rates of evolution of characterizing waveform shape across the time-ordered sequence of sets. Finally, the speech signal is coded based on the produced set of signals. A set of signals which represents relatively low rates of evolution of characterizing waveform shape across the time-ordered sequence of sets may also be produced.

Abstract: An optical connector is disclosed for terminating an optical cable 10 comprising a plastic optical fiber 11 surrounded by a protective jacket 12. The connector includes a housing having an exterior latch 201 that secures it to an adapter 31. The latch is constructed as a cantilever with its fixed end positioned toward a front end of the housing. The connector further includes a cable-holding structure that attaches to the jacket of the optical cable in such a manner that the plastic optical fiber 11 connects to an associated optical device without the use of a ferrule. One cable-holding structure includes a guide tube 45 that is made from metal and is pressed, or insert molded, into the back end of one plastic housing 40. A portion of the guide tube protrudes from the back end of the housing and is crimped onto the optical cable. Here, the optical cable is immovably attached to the housing.

Abstract: Optical switches utilizing electrostatically-driven actuators formed from micro machined plates are disclosed. Under an applied voltage, a movable plate moves toward a fixed plate or a conductive region of an underlying support. The switches further include a mechanical linkage from the actuator to an optical device. The displacement of the movable plate generated at the actuator is transferred, via the mechanical linkage, to the optical device. The optical device, which is positioned in close proximity to optically-aligned spaced optical fibers, is movable into and out of an optical path defined by the optical cores of the optical fibers by the action of the actuator. An "in-plane" optical switch includes an actuator having two vertically-oriented electrodes, which generates a substantially horizontally-directed displacement of the movable plate and the linked optical device.

Abstract: A segment detection system automatically, contactlessly, rapidly, and precisely detects a segment along an edge, such as a boundary, of an object in a digitized image. The segment detection system includes an imager for capturing an image of an object and converting the image into an electrical signal. A computer is connected to the camera for receiving the electrical signal. A machine vision system is associated with the computer and is adapted to analyze the image. A segment detection program is disposed in the computer for driving the computer and the machine vision system in accordance with the present invention. The segment detection program includes an initialization subroutine and a matching subroutine. The initialization subroutine configures the program to search for a particular target polynomial equation. The matching subroutine derives a test polynomial equation that represents a test segment from a test edge of the object based upon an analysis of the image.

Abstract: A method determines the number of servers as a function of time required for a finite server queueing system based on a projected load. The number of servers is chosen subject to the constraint that the probability of delay before beginning service does not exceed a target probability at all times. The finite server queueing system is first advantageously modeled as an infinite-server system and the mean and variance of the number of busy servers at time t is determined and a distribution is approximated. For any time, the number of servers is chosen to be the least number so that the probability that these are all busy is less than the target probability. As an optional refinement, the infinite server target tail probability is then related to the actual delay probability in the finite server system.