Abstract: Counting and division circuits include an input differential stage connected to a cross-coupled differential stage. The input stage includes first and second IGFETS whose gate electrodes are respectively connected to first and second inputs, whose drains are respectively connected to first and second outputs, and whose sources are connected to the drain of a third IGFET whose source is grounded. The cross-coupled stage includes fourth and fifth IGFETs which are cross-coupled in that the gate of the fourth IGFET and the drain of the fifth IGFET are directly connected to the first output and the gate of the fifth IGFET and the drain of the fourth IGFET are directly connected to the second output. The sources of the fourth and fifth IGFETs are connected in common to the drain of a sixth IGFET whose source is grounded.

Abstract: The rectifier sub-assembly, formed by high temperature brazing, is glass encapsulated. It has axially extending leads with enlarged head portions. The sub-assembly is prepared for surface mounting by first flattening the leads outwardly from the enlarged head portions. An electrically insulating, heat conductive epoxy body is molded around the capsule, the enlarged head portions and at least a portion of each of the flattened lead sections. The leads are trimmed and if required, bent into the appropriate shape. After forming, the leads are barrel plated to obtain the best solderable surface for the most reliable electrical connection.

Abstract: The switching speed of bipolar power rectifiers is increased by formation of misfit dislocations in the depletion region, spaced from the substrate/epitaxial layer interface, in order to reduce minority carrier lifetime. The misfit dislocations are formed by the introduction of germanium during epitaxy, and are distributed along the silicon/silicon-germanium interface. Preferably, the germanium containing layer is located proximate the center of the depletion region.

Abstract: The switching speed of bipolar power rectifiers is increased by formation of misfit dislocations in the depletion region, spaced from the substrate/epitaxial layer interface, in order to reduce minority carrier lifetime. The misfit dislocations are formed by the introduction of germanium during epitaxy, and are distributed along the silicon/silicon-germanium interface. Preferably, the germanium containing layer is located proximate the center of the depletion region.

Abstract: The sonar transducer is protected from explosion shock by a variable impedance device, such as a metal oxide varistor, connected in parallel with the energy conversion component. The varistor normally has a very high electrical impedance, but becomes conductive upon application of the very high voltage output of the energy conversion component as a result of a rapid increase in mechanical energy, such as would accompany an underwater explosion in the vicinity of the transducer, to limit both voltage and current to a safe level so that the transducer can thereafter operate within acceptable parameters.

Abstract: The converter has two mixer stages each including a phase locked loop with an oscillator controlled by a phase comparator. The frequency reference to both stages is provided by a single master reference. The frequency of the oscillator in the first stage is offset to accommodate the three different broadcast frequency conventions. A high frequency reference permits the second stage to compensate for noise kilohertz away from the carrier. A local oscillator output which is also phase locked to the master reference is provided for an external video modulator.

Abstract: Television programs are broadcast to a plurality of receiver units in various geographic areas. Each unit has a memory for storage of a designation code representative of its location and a memory for the storage of a blackout tier indication. Prior to the transmission of the program to be blacked out, each unit is separately addressed and provided with a message including a designation code for storage. Then, a globally addressed message provides all receiver units having a selected designation code with a blackout tier indication for storage. A program tier indication is transmitted along with the program to be blacked out. Each unit, upon receiving the transmitted program, compares the transmitted program tier indication and the blackout tier indication in its memory. All receiver units having a stored blackout tier indication which matches the program tier indication are simultaneously prevented from displaying the program to be blacked out.

Abstract: The underwater sound projector includes a hollow-cylindrical metal housing having a recess with an opening. A non-ceramic flexural disc is supported over the opening. Within the recess is a stack of piezoelectric ring elements. A metal drive head transfers force axially from the stack to an annular area on the disc spaced from the center thereof. Foil electrodes are interposed between the piezoelectric rings and situated at the ends of the stack. A stress bolt clamp connects the drive head to the housing with the stack situated therebetween.

Abstract: A wafer with a <100> orientation comprises a strongly doped N layer (substrate), a lightly doped N layer (middle layer) and a lightly doped P layer (top layer). A strongly doped N layer (source layer) is diffused into most of the top layer. An oxide layer is grown. A V groove with a flat bottom is anisotropically etched through openings in the oxide layer. The V groove is etched through the source layer and most of the P layer. The bottom of the groove initially is at a level above the junction between the top layer and the middle layer. Exposure to beam of phosphorous ions forms a shallow implanted channel region proximate the walls of the groove. An unwanted implanted region along the bottom of the groove is also formed. A second anisotropic etch, through the same oxide mask, deepens the groove bottom to a point below the junction, removing the unwanted portion of the implanted region along the groove bottom. The implanted concentration of the channel is later reduced as the gate oxide is formed.

Abstract: An electrical device designed for leadless surface mounting on a PC board has molding compound which surrounds the electrical component and is so shaped as to have an outer surface which defines a flat, so that when the device is placed on the board it will remain in proper location and not roll away. An appropriately shaped mold is provided to accommodate the shape the molding compound simultaneously for a plurality of devices.

Abstract: An encrypted video distribution system includes a signal originating station which distributes television signals in a format unrecoverable by a standard television receiver. In particular, the normally occurring vertical and horizontal synchronizing pulses are deleted and, optionally also, video information is selectively inverted about a voltage reference potential intermediate the black and white levels. To permit synchronization restoration, a keying pulse is transmitted once each video field, and a synchronizing digital code burst transmitted once each frame--all at a fixed, predetermined intra-frame timed relationship. At each authorized subscriber location, the keying pulse and digital code burst are employed to lock a receiver frame clock which derivatively gives rise to all requisite reception-permitting synchronizing pulses. The transmitted information also contains information sufficient to restore the inverted video program content.

Abstract: A cryptographic system is used for the secure transmission of digitized signals to a plurality of receivers. At the transmission end, a key consisting of two blocks, each including a plurality of key fragments, is generated. For each transmission session, different sets of key fragments may be periodically selected from one of the key blocks and used to encrypt the signals. Data indicative of the set selection is generated. The key is distributed to each receiver. The set selection data is transmitted to all receivers along with the encrypted signals and used to construct the key fragment set for decryption of the transmitted signals. During the transmission session, the other key block may be varied to form a replacement key which is distributed to each receiver. At the end of the session, the functions of the key blocks are interchanged in all receivers at one time by selecting a set in the varied key block for use in encryption and decryption.

Abstract: A feedback coder, which employs simple CMOS push/pull amplifiers as gain elements, along with a bistable circuit, in its preferred embodiment takes the form of a second-order delta-sigma modulator. The output of the modulator is converted into pulse code modulated words by a finite impulse response filter which incorporates a partial coefficient generator utilizing simplified logic. The generator output is provided to an accumulator in which the stages operate at reduced speed. A simple multiplexer generates a serial output. The entire converter can be integrated on a semiconductor chip of relatively small area.

Abstract: Blank tickets, for use in an instant lottery game or the like, can be imprinted in a secure manner in an enclosed point of sale ticket-issuing apparatus under the control of a central computer. Prior to exposure of the ticket, an adhesive-backed sheet with a scratch-off material coating on areas aligned with the printing is applied to the surface of the ticket. The adhesive will cause obvious damage to the ticket to void same if an attampt is made to remove the label.

Abstract: Permeation of sea water through the protective rubber housing to the conductive portions of the exterior surface of the ceramic or other pressure-sensitive element results in the development of a low insulation resistance which leads to failure of the unit. The operational life of the unit is extended through the application of an acoustically transparent water impervious layer, interposed and bonded between the exterior surface of the ceramic or other pressure-sensitive element and the interior surface of the rubber housing.

Abstract: Recirculation is prolonged in a broadband microwave loop by flattening the overall frequency response of the loop. A bandpass filter, tuned to the input signal frequency, is placed in the loop after the broadband amplifier. A frequency discriminator responsive to the input signal controls the filter driver.

Abstract: A substantially solid transparent molded plastic body focuses light from an internal point to a point external to the body. The body has a center section with a surface having the curvature of a Cartesian Ovoid of revolution and a peripheral section. The peripheral section includes an inner refracting surface in the shape of a diverging truncated cone whose apex substantially coincides with the internal point and an outer reflecting surface in the shape of a polynomial curve of revolution. The slope of the outer surface causes it to reflect light rays between the refractory inner surface and the internal point. A light source such as an LED, or a photo-detector, may be immersed in the body at the internal point.

Abstract: The input digital signal is applied to a transition detector which causes an up/down counter to increment or decrement each time a transition is detected. The output of the counter is utilized to address a read only memory (ROM) which, in turn, generates binary words representing first and second integers. These binary words are used to control a programmable divider to generate an output having a frequency which moves between two values corresponding to the digital input. The rate at which the frequency changes between the two values is controlled by the ROM contents. In the implementation, the frequency changes with a raised cosine shape.

Abstract: A rectifier designed for leadless surface mounting on a P.C. board has a cylindrical body situated between two disk-like end parts. The end parts extend radially beyond the surface of the body defining a recess adapted to receive epoxy compound. A plurality of rectifiers are situated end-to-end within elongated cylindrical cavities in a mold. The end parts cooperate with the cavity walls to seal each individual recess when the mold halves are closed. Openings in the cavity wall aligned with each recess permit epoxy compound to enter each recess and be cured. Leads may be attached to the end parts after the molding operation to convert the rectifier into an axial lead device, if required.