Abstract: A reflow furnace in which the rate at which the temperature of the parts being processed can change can be varied throughout the furnace in order to provide a high initial rise rate, a period of low or no rise, and a very fast rise to a temperature above the melting point of solder followed by a fast drop to a temperature below the melting point of the solder. The entire operation is performed in an atmosphere of air, inert gas, active gas, or combustible gas. In a stabilization zone and a reflow zone, the primary heating mode is forced, controlled convection that is perpendicular to surface of an assembly to be soldered.

Abstract: A microelectronic-based timekeeping apparatus having several display means, such as liquid crystal displays, that change color to indicate the time-of-day, and user accessible switches for setting modes of operation, are mounted within an aluminum frame. Time-of-day is represented by the dynamically changing relationship among the several display means. Display means consist of light valves alone, or light valves in combination with a backlighting means. The apparatus is suitable for integration with a work of abstract art and may be free-standing or hung on a wall.

Abstract: An embodiment of the present invention is a method for determining the cleanliness of a semiconductor wafer initially deposited with polysilicon, patterned with photoresist, processed, and then having the resist removed under standard conditions. The method comprising the steps of: depositing a thin TEOS film over the entire surface of a wafer; exposing said wafer to a solution of hot potassium hydroxide (KOH) that attacks polysilicon and is highly selective to and does not etch said TEOS film, the exposing such that if any pin hole exists in the TEOS film an underlying layer of polysilicon is attacked vigorously; and inspecting said wafer for a visual indication in said polysilicon layer of whether or not said polysilicon layer was attacked by the exposure to said potassium hydroxide (KOH).

Abstract: The present invention comprises an articulator for registering an upper dental cast to a lower dental cast. The articulator includes an upper member subassembly with left and right sides and a lower member subassembly with left and right sides each composed of plastic material. The articulator further has at least one hinge member engaging one of the members allowing one of said members to pivot relative to the other member and a coupling means flexibly connecting the upper member subassembly to the lower member subassembly. The articulator further includes disconnectable connection means joined to one of the members for disengaging the upper member subassembly and the lower member subassembly whereby the upper and the lower member subassemblies may be separated, and a clipping means for removably securing the upper member subassembly to the upper dental cast and the lower member subassembly to the lower dental cast such that said upper and lower dental casts can be properly and flexibly aligned.

Abstract: An AC solid state relay in a single inline package (SIP) comprised of dual silicon controlled rectifiers (SCRs) with a supporting circuitry mounted directly on an alumina substrate with molecularly bonded copper metalization layers and heat spreader all coated in a thermally conductive epoxy. And a DC solid state relay in a single inline package (SIP) comprised of an NPN power transistor with a supporting circuitry mounted directly on an alumina substrate with molecularly bonded copper metalization layers and heat spreader all coated in a thermally conductive epoxy.

Abstract: An electronic housing structure including an enclosure for containing at least one electronic device having a plurality of user interface switches. The electronic housing structure further has a user interface pad attached to the enclosure near the user interface switches for operating said user interface switches. The user interface pad further seals the enclosure to completely seal and protect the electronic device. The enclosure and the user interface pad are composed of a waterproof, dust-proof and mud-proof material whereby said electronic device can be operated in an outdoor condition.

Abstract: A lower power, noise rejecting TTL-to-CMOS input buffer, without the use of a current consuming voltage reference, has the characteristic of recognizing a logic LOW as less than 0.8 volts and a logic HIGH as greater than 2.0 volts for DC TTL signals while drawing only leakage current from its Vcc power supply, and simultaneously possesses the characteristic of rejecting high-amplitude Vin noise. For an input signal rapidly rising from zero to three volts, the buffer output switches at an input signal level of approximately 2.5 volts; and for the input signal rapidly falling from 3 to zero volts, the buffer output switches at an input signal level of approximately 1.4 volts.

Abstract: The present invention provides a verification plate to verify the accuracy and precision of a mask inspection system in detecting contaminated particles. The verification plate is developed on a substrate having a plurality of predefined glass, i.e., transparent, and chrome, i.e., opaque, patterns. A predetermined number of verification particles each with a predefined size, shape, and location are securely disposed on these glass-chrome patterns. The verification plate is preferably produced having both the glass-chrome patterns and the particles arranged in an orderly manner such that a verification process can be automated under the control of a computer program.

Abstract: A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of optical positioning tracks on at least one of said sides of said media, and a media type code optically embossed on at least one of said sides of said media. The media type code contains information about the physical properties of the particular diskette that will allow a disk drive unit to auto-configure itself to allow optimum data communication and performance.

Abstract: An embodiment of the present invention is a temperature forcing system and method for precision temperature control of a device-under-test. The system comprises a thermal test head suspended by a support arm that receives a temperature controlled air flow through an output hose from an air supply system. A pair of temperature sensors, one attached to the device-under-test and the other in the output hose, are used differentially by a closed-loop temperature controller when the temperature of the device-under-test comes within a temperature window surrounding a target temperature setpoint point. Outside the temperature window control is linear and within the temperature window control is compensated by a correction factor obtained during a single calibration test that amalgamates the effects of the mass of the device-under-test, the ambient conditions and other factors.

Abstract: An embodiment of the present invention is a shipboard GPS positioning system having data links to outlying tailbuoys equipped with respective GPS receivers. On ship, an Intel 386-based microcomputer system collects data from various ship's equipment including the ship's GPS receiver and data from the several tailbuoy units. A computer-implemented process located in the microcomputer system controls the following processes. Periodically each GPS receiver produces updated pseudo ranges (PRs) and these are time-tagged. The time-tagged PRs for the ship are aligned according to their time tags with their counterpart PRs from the tailbuoys. The raw PRs are then passed through a Kalman mathematical filter to produce filtered pseudo-ranges (PRs). A position solution is then attempted for each GPS receiver using the PRs. The filters provide statistical data that is used to rate the quality of each PR in a weighted least squares solution process.

Abstract: For enabling a static, random-access-memory (500) bit lines (556 and 558) pre-charging circuit (518), employed is an address-change-detection circuit (510) having a plurality of address-change-detectors (570 and 572) each for detecting a change in an associated SRAM addressing signal and, driven by the address-change detectors (570 and 572), a pulse generator (700) driving the pre-charging circuit (518).

Abstract: A single-transistor EEPROM device of the present invention comprises memory transistors in banks similar to NAND structures wherein the control gates of the memory transistors have negative voltages applied in various modes that allow reading, writing, and programming regardless of the V.sub.th of nonselected memory transistors in a bank. Programming and erasing results from various combinations of negative and positive voltages are used on the select gates together with positive voltages less than that alone which is necessary to induce Fowler-Nordheim tunneling are applied to the bit lines.

Abstract: A removable toilet seat cover comprising deep pile carpet for cushioning of the rim of a rigid toilet seat and elastic bands that aid the elderly in positioning the cover on a seat for securing by the closing of overlapping flaps equipped with VELCRO.RTM.-type fabric hook-and-link fasteners.

Abstract: A sensitive and fast low voltage lamp system controller to provide safe operation of "bare wire" systems that are particularly attractive for use in exhibition and tradeshow booth lighting. The high sensitivity is achieved by emphasizing high frequency noise present during shorts and by proportionately limiting the instantaneous current that tracks the line AC voltage waveform; fast response is provided by a power FET coupled to a bridge rectifier in series with the load and both then in series with a protection relay.

Abstract: A method for determining the thickness of a layer of material, such as soil, wood, ice or coal, that utilizes a microstrip antenna as a thickness measuring sensor. The sensor is positioned over the layer and a value for a parameter of the antenna such as conductance or resonant frequency is measured. The value is compared to a calibration table of values and the thickness of the layer is determined by interpolation. Alternatively, the value is compared to a control value to initiate a decision process. The decision could be that a layer of ice is building up on a wing of an aircraft or that an explosive device is buried under a layer of soil.

Abstract: An embodiment of the present invention is a voltage controlled oscillator (VCO) comprised of a differential pair of transistors that have respective positive feedback paths with phase-lead networks cross-coupled. Each positive feedback path on each side has two different phase-lead branches. The two phase-lead branches have the same phase differences on each side of the differential pair, in order to maintain a symmetry that improves common-mode noise rejection on a voltage control differential input. Current-steering is used to control the mixture of currents that arrive at the bases of the differential transistor pair from the respective two different phase-lead branches, and thereby changing the frequency of the VCO.

Abstract: A method utilized with an underground conductor detection system for calibrating a downhole transmitter to compensate for detuning of the transmitter antenna by geologic formations. The method comprises sending a synchronization signal to the transmitter antenna, measuring the current flow through the transmitter antenna and adjusting the current to a constant level, and measuring the phase difference between the transmitter antenna current and the synchronization signal. A receiver transmitter is calibrated by sending a synchronization signal to a radiating antenna in the receiver that in turn sends a calibration signal to the receiver antenna that is directed over the entire signal pathway back to surface located signal processing equipment. Another method of underground conductor detection sends a surface wave to the downhole receiver to cancel the effect of the surface wave modulation on a target wave being radiated by the underground detector.

Abstract: A crawling insect trap comprising a tube and perforated wicks. The wick contains one or more bioactive compounds, among which may be poisons, attractants and birth control agents. The outer surface of the tube is coated with an unpalatable agent to deter children and animals from eating the trap. The trap is color coded to allow rotation of active agents. An adhesive strip is provided to facilitate placement of the trap.

Abstract: A method for remotely monitoring conditions such as carbon monoxide or methane gas concentration, longwall roof support pressure, machine parameters or uncut coal, trona or potash layer thickness in a natural resource mining system such as a longwall or continuous mine system. The method utilizes a plurality of sensors connected to low magnetic moment transmitters, e.g. 0.1 ATM.sup.2, or high magnetic moment transmitters, e.g. 2.5 ATMhu 2, that transmit colleted data during multiple short burst transmission periods. Prior to transmission, the data is converted to a digital word format. An algorithm in the transmitter microcomputer ensures that random time intervals exist between data transmission bursts thus preventing a data transmission clash at the central receiver. A microcomputer algorithm in the central receiver protects against data contention caused by simultaneous transmission from several sensors.