Abstract: A gaming apparatus including a rigid circular ring with a plurality of hollow spokes projecting radially from a central hub having a cylindrical cavity with passageways from said cavity to each of said spokes.

Abstract: An embodiment of the present invention is a site controller that comprises a microcomputer with a RAM for main memory and an EPROM for program memory, an interface for accepting RS-485 data and voice communication on respective differential wire pairs from a daisy chain of student response keypad terminals, a public telephone data access arrangement with hybrid for sending and receiving voice over a dial-up line, a universal asynchronous receiver-transmitter for data communication by modem with a remote host site via an X.25 PAD and an audio processor for half-duplex communication between an instructor and a student that has voltage controlled amplifiers and side chain devices that reduce audio amplifier gain during periods of silence in order to eliminate feedback howl and adjustable delay and threshold devices for gating the respective channels through in the half-duplex mode.

Abstract: An embodiment of the present invention is a system for automatically pointing a directional antenna. The system comprises two GPS antennas mounted at horizontally opposed extremities of the directional antenna, the placement is such that the GPS antennas lie on a line having a normal vector approximately parallel to a boresight of the directional antenna. The outputs from the GPS antennas are downconverted to a measurement frequency and differentially phase compared for each of a plurality of radio visible GPS satellites. A measurement controller that receives the phase comparisons. A navigation computer receives measurements from the measurement controller and uses a microprocessor to calculate the GPS latitude and longitude and the attitude angles of the pair of GPS antennas. A servo points the directional antenna at a particular target communications satellite, based on the computed azimuth, elevation, latitude, and longitude, as provided by the navigation computer.

Abstract: An embodiment of the present invention is a pellicle for use on a photomask reticle used in conjunction with deep ultraviolet light wavelengths. The membrane of the pellicle comprises a purified fluoropolymer that has been spin coated on a substrate of nitrocellulose and then separated and mounted on an aluminum frame. The aluminum frame has vents that filter air of contaminants and which allow an equalization of air pressure on both sides of the pellicle membrane when a peel-off backliner is in place on the opposite side of the frame. A permanent bond is made between the membrane and frame and a sticky adhesive is used to keep the backliner on the frame until peel-off. The sticky adhesive is such that the backliner may be re-attached a plurality of times.

Abstract: An improved power factor DC power supply in accordance with the present invention (100 or 200) employs a power factor correcting network ( 120), a full-wave rectifier means (122), a pair of filter capacitors (124 and 126 ) , and three current steering diodes (128, 130 and 132). The power factor correcting network ( 120) includes both an inductor means (136 and 240) and a capacitor (138), the combination configured to improve the power factor DC power supply (100 or 200) presents to the AC power-line (102) by reducing the level of harmonic currents the DC power supply generates on the AC power-line. The filter capacitors (124 and 126) are configured with the current steering diodes (128, 130 and 132) such that the filter capacitors are charged in series and discharged in parallel.

Abstract: Receiver hitch mechanism including a receiver insert is mounted to a vehicle having a receiver type hitch. The receiver insert includes two apertures which a securing pin is indexed through. The first aperture is not within the receiver hitch and contains a threaded interior which coincides with a threaded exterior of a securing pin. The second aperture is located inside the trailer hitch and includes an interior wedge member which extends towards the interior of the receiver insert and is parallel with the securing pin. The securing pin includes one tapered end for frictional engagement with both the wedge member and the interior wall of the receiver hitch, and a second end for grasping, then rotating the securing pin.

Abstract: An embodiment of the present invention is a lighting system including a sense transformer with two primaries and a secondary for receiving alternating current (AC) from a power source, a low ohmage resistor placed across the sense transformer secondary winding for preventing saturation of the core of the sense transformer, an analog comparator for detecting when ground-fault signals in the sense transformer secondary winding exceed a threshold voltage and digital counters for testing whether or not a ground-fault condition persists longer than three consecutive half-cycles of the received alternating current from the power source.

Abstract: A microcomputer controlled media and disk testing system having a media servowriting subsystem and a certification subsystem. The servowriting subsystem comprises a precision magnetic read/write (R/W) head positioning device based on a laser positioning device and pattern generating and writing circuitry. The certification subsystem comprises of an apparatus to open bit windows and adjust thresholds and to assess the quality and nature of defects from the positions of bits and their analog characteristics when read back relative to such windows.

Abstract: An embodiment of the present invention is a lighting system comprising a full-wave bridge, a filter capacitor, a control logic that drives a pair of output transistors and an output network that includes an output transformer that powers a pair of fluorescent lamps. The output transformer has a natural resonant frequency that will produce maximum power transfer to the lamps if the transistors are switched by the control logic at a rate near the natural resonant frequency. Precise frequency control within the control logic maintain consistent levels of output current through the lamps by phase lock loop (PLL) synchronizing its output switching frequency to the sixty Hz commercial line frequency, as sampled through a resistor and a digital integrator that prevents false triggering.

Abstract: A pair of similar, 32-bit, error detection and correction devices, including a "lower 32-bit" device (210) and an "upper 32-bit" device (212) are configured as a 64-bit, error detection and correction system. When a (64-bit) word of data is being stored in memory, the lower 32-bit device (210) develops, on an inter-device bus (226), signals representing generation partial check bits. The upper 32-bit device (212) receives the partial check bits (226), and develops signals representing final check bits (236) for storage with the corresponding data word in memory (220 and 234). When a (64-bit) word of data is being retrieved from memory, from signals representing check bits retrieved from memory (222), the lower 32-bit device (210) generates on an inter-device bus (224), signals representing correction partial syndromes.

Abstract: A daisy chain voice-data terminal for communicating data and voice signals between remote locations, comprising, according to an embodiment of the present invention, a microcomputer with a RAM for main memory and an EPROM for program memory, a membrane keypad connected to an input port of the microcomputer, a liquid crystal display adjacent to the keypad and connected to an output port of the microcomputer, a microphone and preamplifier, a differential output audio amplifier, a relay controlled by the microcomputer to switch the differential output audio amplifier on and off a daisy chain cable connected to other response keypads and a site controller, an RS-485 serial input/output to interface the microcomputer to the daisy chain cable, a switching regulator to provide five volts to the logic circuits, and a separate three-terminal linear regulator to supply five volts to the audio circuits.

Abstract: An embodiment of the present invention relates to a worldwide network of differential GPS reference stations (NDGPS) that continually track the entire GPS satellite constellation and provide interpolations of reference station corrections tailored for particular user locations between the reference stations Each reference station takes real-time ionospheric measurements with codeless cross-correlating dual-frequency carrier GPS receivers and computes real-time orbit ephemerides independently. An absolute pseudorange correction (PRC) is defined for each satellite as a function of a particular user's location. A map of the function is constructed, with "iso-PRC" contours. The network measures the PRCs at a few points, so-called reference stations and constructs an iso-PRC map for each satellite. Corrections are interpolated for each user's site on a subscription basis.

Abstract: An in-circuit emulator (ICE) for hardware/software development and debugging microprocessors. Program execution reconstruction is extracted from an on-board cache memory. An external ICE enclosure interfaces to a target system microprocessor via a cable and a buffer/interface pod. A control program directs a non-intrusive emulation and a monitor program resides in a personal computer host and supports ICE commands. The monitor program allows a user to follow a target system's program flow, to capture related processor information, to make program modifications, and allows the user to restart programs. An on-line disassembler presents a display so as to allow the designer to examine memory, using instruction mnemonics rather than hexadecimal values, thus improving the designer's ability to read program memory. A bit trace buffer records the state of each the microprocessor's signals during each cycle of each instruction.

Abstract: A CMOS device having many output channels at least one of which channel includes a first pair of pull-up/pull-down of transistors between a "noisy Vcc and noisy ground", a second pair of pull-up/pull-down of transistors between a "quiet Vcc and quiet ground", and logic to switch the transistor pairs such that initial switching of an output is powered by the noisy Vcc and ground, and maintenance of an output state is powered by the quiet Vcc and ground. Quiescent channels are decoupled from active channels and will hold their assigned output levels.

Abstract: An embodiment of the present invention is a dimmable, high power factor, high efficiency electronic ballast comprising, on a single integrated circuit chip, a shunt regulator, a voltage reference, a high-temperature shutdown, an undervoltage lockout, a timer for start-up and restarting, a variable oscillator, a mode control, an op-amp for receiving a signal proportional to lamp current and for controlling the variable oscillator or the duty-cycle of pulses output in a closed-loop servo, and active power factor correction including an analog multiplier for receiving an AC voltage and an AC current sample, and for multiplying these together to result in a comparison with a DC voltage. The comparison produces a control signal for a MOSFET switch on a boost converter transformer that actively corrects the power factor at a rate set by the oscillator.

Abstract: A pair of transistors (110 and 112) configured with their channels connected in series. The gate of the "upper" transistor (110) is coupled to a relatively low-voltage, DC power supply voltage by a voltage-clamping and current-steering diode (144); to a relatively high-voltage, DC power supply voltage by the series combination of a current-steering diode (152) and one voltage-clamping zener diode (154 and 156) and coupled to the source of the "upper" transistor by a charge-removing resistor (162).

Abstract: An embodiment of the present invention is a communications system for multiple users sharing the same maximal length code (MLC) in a code position modulation multiple access environment. A 1023 chip length code is transmitted with reference to an independent coordinated time source. The code repeats every time after 1023 chips have been transmitted. The MLC will begin each time period with the first through 1023.sup.rd chip, depending on the data to be sent and the identity of the user transmitting it. The chips belong to the MLC that were not sent at the beginning of a time period are sent at the end to complete the MLC each time period in a wrap around fashion. Each time period can be aribtrarily divided into subsections embracing, for example, sixteen chip times. When so divided, more than sixty subsections are possible from one 1023 chip MLC. Respective users are each assigned a subsection.