Abstract: A transducer sensor is positioned within a hollow of the body of a housing. The housing has an extending alignment pin, which pin coacts with a corresponding slot or aperture in the wall of a vessel whose pressure or temperature is to be monitored. The transducer body is associated with a connector where the alignment pin is placed and extends from the housing in a fixed relation to the connector. A suitable aperture or slot in the wall of the vessel to be monitored accommodates the extending pin whereby when the transducer is placed in the vessel aperture the connector associated with the transducer is always located in proper position. Positioned on the housing is a sliding nut which can move in a direction parallel to the central axis of the housing and either to the right or left.

Abstract: A high temperature pressure sensing system (transducer) including: a pressure sensing piezoresistive sensor formed by a silicon-on-insulator (SOI) process; a SOI amplifier circuit operatively coupled to the piezoresistive sensor; a SOI gain controller circuit including a plurality of resistances that when selectively coupled to the amplifier adjust a gain of the amplifier; a plurality of off-chip contacts corresponding to the resistances, respectively, for electrically activating the corresponding resistances and using a metallization layer for the SOI sensor and SOI ASIC suitable for high temperature interconnections (bonding); wherein the piezoresistive sensor, amplifier circuit and gain control circuit are suitable for use in environments having a temperature greater than 175 degrees C. and reaching between 250° C. and 300° C., and wherein the entire transducer has a high immunity to nuclear radiation.

Abstract: A method and apparatus for measuring knocking in internal combustion engines employs a high temperature transducer, which transducer is mounted within a cylinder. The output of the transducer is solely related to pressure. The output signal from the transducer is directed to the input of a high frequency amplifier associated with a band pass filter. In this manner the combustion signal can be filtered out and one provides a signal which is only indicative of the knocking signal and of the knocking frequencies. This signal can be analyzed simply and effectively by the use of a processor such as a multimeter or a microprocessor. In a similar manner the processor can compare the combustion and knocking signal without the band pass filtering with the knocking signal with the combustion signal filtered out.

Abstract: A displacement transducer includes a load cell structure having a thick outer peripheral area, a thick inner central area and two symmetrical thin beams. The two beams are disposed along a common diameter of the structure and joins the outer peripheral area and the inner central area. At least one strain gauge is placed on a surface of one beam and at least one strain gauge is placed on a surface of the second beam. A top diaphragm cover member is secured to a top surface of the outer peripheral area and covers the two beams.

Abstract: A method for selectively enhancing a voice telephone call from a first location to a second location over a public switched telephone network, including receiving audio signals from a conventional telephone using a first device positioned at the first location; and, in a first mode, passing the received audio signals to the public switched telephone network in a substantially unaltered manner; and, in a second mode, generating data indicative of the received audio signals using the first device; multiplexing the generated data with other data desired to be communicated using the first device; and, transmitting the multiplexed data over the public switched telephone network; wherein, the transmitted data is suitable for being received from the public switched telephone network and de-multiplexed to generate reproduced audio signals indicative of the received audio signals and the other data by a second like device.

Abstract: A method of fabricating a semiconductor-on-insulator device including: providing a first semiconductor wafer having an about 200 angstrom thick oxide layer thereover; etching the first semiconductor wafer to raise a pattern therein; doping the raised pattern of the first semiconductor wafer through the about 200 angstrom thick oxide layer; providing a second semiconductor wafer having an oxide thereover; and, bonding the first semiconductor wafer oxide to the second semiconductor wafer oxide at an elevated temperature.

Abstract: A pressure sensor including: a deflectable diaphragm including a substantially central boss and channel; and, an optical waveguide having first and second arms, wherein the first arm is substantially aligned with an edge of the boss and the second arm is substantially aligned with an edge of the channel.

Abstract: A differential pressure sensor has a semiconductor wafer having a top and bottom surface. The top surface of the wafer has a central active area containing piezoresistive elements. These elements are passivated and covered with a layer of silicon dioxide. Each element has a contact terminal associated therewith. The semiconductor wafer has an outer peripheral silicon frame surrounding the active area. The semiconductor wafer is bonded to a glass cover member via an anodic or electrostatic bond by bonding the outer peripheral frame to the periphery of the glass wafer. An inner silicon dioxide frame forms a compression bond with the glass wafer when the glass wafer is bonded to the silicon frame. This compression bond prevents deleterious fluids from entering the active area or destroying the silicon. The above described apparatus is mounted on a header such that through holes in the glass wafer are aligned with the header terminals.

Abstract: A pressure sensor header for a pressure transducer includes a header shell having a sensor cavity formed therein, a sensor element disposed in the sensor cavity, a fluid medium disposed in the sensor cavity, an isolation diaphragm closing the sensor cavity, and a joining arrangement disposed at an interface of the isolation diaphragm and the header shell, the joining arrangement joining the isolation diaphragm with the header shell. The isolation diaphragm is an integral unit comprising a thin membrane surrounded by a thicker outer ring. The joining arrangement has a recessed female joining element formed in one of the outer ring of the isolation diaphragm and the header shell, and a protruding male joining element formed on the other one of the outer ring of the isolation diaphragm and the header shell, the male joining element received in the female joining element.

Abstract: A portable security device for providing secure communications over a plurality of networks is presented. In one embodiment, the device comprises, at least one communication port for transfer of audio data, at least one communication port for transfer of digital data, a keypad, an encoding/decoding device, a conversion device operable to covert between audio and digital data and a processor, in communication with a memory, the keypad, the said encoding/decoding device, operable to execute code for selecting a configuration of a transmission and a reception port from among said communication ports dependent upon the presence of a network communication device and an input/output device in communication with said selected ports, providing data received from said selected reception port to said encryption/decryption device for encrypting; and providing said encrypted data to said selected transmission port.

Abstract: A single wire interface for a transducer transmits the transducer output as a frequency modulated signal over one single wire during one interval. During a second interval a reference signal is transmitted as a frequency modulated signal. Both the transducer output and the reference signal output are processed by the same circuitry during the respective intervals to provide both frequency modulated signals. The frequencies of the two signals are measured and then the ratio of the two periods which is the reciprocal of the two frequencies is calculated. This ratio is the direct measure of the output of the transducer and when provided eliminates sources of errors.

Abstract: A pressure transducer assembly including: a pressure sensor header; a transducer assembly member; and a joining arrangement disposed at an interface of the header and the transducer assembly member, for joining the header with the transducer assembly member, the joining arrangement including: a recessed female joining element formed in one of the header and the transducer assembly member; and a protruding male joining element formed on the other of the header and the transducer assembly member, the male joining element received in the female joining element.

Abstract: An ultra high temperature hermetically protected transducer includes a sensor chip having an active area upon which is deposited piezoresistive sensing elements. The elements are located on the top surface of the silicon wafer chip and have leads and terminals extending from the active area of the chip. The active area is surrounded with an extending rim or frame. The active area is coated with an oxide layer which passivates the piezoresistive sensing network. The chip is then attached to a glass pedestal, which is larger in size than the sensor chip. The glass pedestal has a through hole or aperture at each corner. The entire composite structure is then mounted onto a high temperature header with the metallized regions of the header being exposed to the holes in the glass pedestal; a high temperature lead is then bonded directly to the metallized contact area of the sensor chip at one end. The leads are of sufficient length to extend into the through holes in the glass pedestal.

Abstract: A semiconductor heterostructure based pressure switch comprising: first and second small bandgap material regions separated by a larger bandgap material region; a third small bandgap material region within the region of larger bandgap material, the third material region and larger bandgap material region defining at least one quantum dot; and, first and second electrodes electrically coupled to the first and second small bandgap material regions, respectively, wherein the electrodes are sufficiently proximate to said quantum dot to facilitate electron tunneling there between when a pressure is applied to the bandgap material defining the quantum dot.

Abstract: A circuit produces an output that is proportional to the molar density of gas in a chamber. The circuit employs an operational amplifier which measures the temperature using a RTD or other element that changes resistance with temperature. The RTD is placed such that it produces a decreasing current draw at the inverting input of the operational amplifier as the temperature increases. This decreasing current draw in turn produces a decreasing voltage at the output of the operational amplifier. By changing the ratio of resistors connected to the non-inverting terminal of the operational amplifier one changes the offset of the output voltage. By changing the feedback resistor connected from the output of the operational amplifier to the inverting terminal and connecting the output of the inverting terminal to a voltage divider including the RTD device, one can change the gain with temperature.

Abstract: A pressure transducer apparatus including: first and second pluralities of piezoresistors each coupled in Wheatstone bridge configurations, wherein the bridges are coupled together to provide a first output being indicative of a differential pressure; and, a third plurality of piezoresistors coupled in a Wheatstone bridge configuration and being suitable for providing a second output being indicative of an absolute line pressure. A compensator may be employed for adjusting the first output for line pressure variation responsively to the second output.

Abstract: A field emission display comprises an anode comprising a matrix of pixels and a cathode comprising an insulating layer defining a plurality of wells having a conductor therein. A first conductive layer forms a plurality of conductive pads, each of the conductive pads corresponding to one of the wells. A plurality of nanostructures are electrically coupled to the conductive pads. A second conductive layer is formed over the insulating layer and provides a plurality of gate electrodes. When a potential between the conductive pads and gate electrodes exceeds a threshold voltage, the nanostructures emit electrons that impinge on the pixels.