344 results about "Temperature induced" patented technology

The present invention provides a primary-side flyback power converter that supplies a constant voltage output and a constant current output. To generate a well-regulated output voltage under varying load conditions, a PWM controller is included in the power converter in order to generate a PWM signal controlling a switching transistor in response to a flyback voltage sampled from a first primary winding of the power supply transformer. Several improvements are included in this present invention to overcome the disadvantages of prior-art flyback power converters. Firstly, the flyback energy of the first primary winding is used as a DC power source for the PWM controller in order to reduce power consumption. A double sample amplifier samples the flyback voltage just before the transformer current drops to zero. Moreover, an offset current is pulled from a detection input of the double sample amplifier in order to generate a more accurate DC output voltage. The offset current is generated in response to the temperature in order to compensate for temperature-induced voltage fluctuations across the output rectifier. Ultimately, in order to maintain a constant output current, the PWM controller modulates the switching frequency in response to the output voltage.

A highly sensitive silicon micro-machined sensor package is provided for use in a micro-g environment that can also resist high shock in excess of 5000 g. The sensor is provided to measure acceleration in cooperation with associated electronics which are required to have electrical contact with sensor elements. The sensor is sealed in a high vacuum environment, and is arranged and designed to be free of temperature induced stress to the sensor. The sensor die package assembly comprises a silicon micro-machined sensor die, a ceramic package, two contact springs, a shorting clip, solder preform, a metal lid and a getter foil for ensuring a good vacuum for an extended period. The sensor die comprises a moving mass with eight supporting flexures on both sides of the proof mass. The proof mass's movement is protected on both sides by a top and a bottom cap. Acceleration applied to the package and the die causes the proof mass to move vertically in relation with the adjacent caps. The changes in distance between the proof mass and the caps in turn generate a change in an electrical signal which corresponds to the capacitance changes between the gaps. The sensor die package arrangement provides that the sensor die be secured within an evacuated ceramic case. Electrical connections made between external contacts of the case and contacts of the sensor die within the case are made through conductive springs, thereby minimizing materials in the interior of the case which would outgass in the vacuum environment.

The present invention provides a system and method for controlling one or more light-emitting elements which are driven by forward currents to generate mixed light for use, for example, through a luminaire. The system has one or more light sensors for acquiring feedback optical sensor data and a user interface for providing reference data representative of a desired mixed light. The system also has a controller for transforming either the sensor data or the reference data into the coordinate space of the other and to determine a difference between the sensor and the reference data in that coordinate space. The controller is configured to adjust the forward currents during operating conditions so that the sensor data matches the setpoint data. The present invention also provides a system and method that can at least partially compensate certain temperature induced effects when transforming the optical sensor or the reference data.

The present invention provides a primary-side flyback power converter that supplies a constant voltage output and a constant current output. To generate a well-regulated output voltage under varying load conditions, a PWM controller is included in the power converter in order to generate a PWM signal controlling a switching transistor in response to a flyback voltage sampled from a first primary winding of the power supply transformer. Several improvements are included in this present invention to overcome the disadvantages of prior-art flyback power converters. Firstly, the flyback energy of the first primary winding is used as a DC power source for the PWM controller in order to reduce power consumption. A double sample amplifier samples the flyback voltage just before the transformer current drops to zero. Moreover, an offset current is pulled from a detection input of the double sample amplifier in order to generate a more accurate DC output voltage. The offset current is generated in response to the temperature in order to compensate for temperature-induced voltage fluctuations across the output rectifier. Ultimately, in order to maintain a constant output current, the PWM controller modulates the switching frequency in response to the output voltage.

The present invention provides a system and method for controlling one or more light-emitting elements which are driven by forward currents to generate mixed light for use, for example, through a luminaire. The system has one or more light sensors for acquiring feedback optical sensor data and a user interface for providing reference data representative of a desired mixed light. The system also has a controller for transforming either the sensor data or the reference data into the coordinate space of the other and to determine a difference between the sensor and the reference data in that coordinate space. The controller is configured to adjust the forward currents during operating conditions so that the sensor data matches the setpoint data. The present invention also provides a system and method that can at least partially compensate certain temperature induced effects when transforming the optical sensor or the reference data.

A thermal insulation container for storing materials at predetermined temperatures over extended periods including thermal energy storage units and means for substantially eliminating thermal conductors and providing improved insulation properties by mechanically absorbing temperature induced frictional forces. Highly efficient vacuum thermal insulators embedded within components of the container contribute significantly to its superior temperature maintaining characteristics.

Multiple criteria are monitored and controlled to enhance the success of direct-metal deposition, including greater control over factors such as deposit layer height / thickness, sub-harmonic vibration, contour path shape, powder mass flow, and deposition speed, and stress accumulation. Sensors are used to monitor some or all of the following parameters during the deposition process: deposit height, width, temperature, and residual stress. A predetermined limit with respect to the yield strength of the material is preferably set. If the stress exceeds that limit sensors will automatically introduce one or more remedial measures, the priority of which is established using a look-up table generated in accordance with prior experimental knowledge. To control temperature induced distortion and stress, an infrared temperature detector may be used in conjunction with a controller to reduce temperature, increase speed and decreased power for purpose of stress management.

Polymeric nanoencapsulation methods, which combine sonication and nonsolvent temperature induced crystallization, are provided. The steps include (a) providing active agent nanoparticles having an average diameter between about 5 and about 100 nm; (b) treating said active agent nanoparticles (e.g., a superparamagnetic material) with an anionic surfactant to form modified active agent nanoparticles; (c) mixing the modified active agent nanoparticles with a solution of a polymer in a solvent at a first temperature, which is greater than the melting temperature of the polymer and less than the boiling point of the solvent to form a first mixture, said mixing comprising the use of sonication; (d) mixing a non-solvent with the first mixture to form a second mixture, the non-solvent being a non-solvent for the solvent and for the polymer and having a boiling point greater than the melting temperature of the polymer; (e) sonicating the second mixture to form an emulsion; and (f) cooling the emulsion to a second temperature and at a rate effective to precipitate polymeric nanoparticles comprising the polymer with the modified active agent nanoparticles dispersed therein.

The present invention concerns a fingerprint sensor which is small; demonstrates high sensitivity, low power consumption, high data acquisition rate and is insensitive to vibration and pressure. The sensor produces a high contrast fingerprint representation and is not subject to repeated deformation which could potentially reduces its lifetime. The fingerprint sensor has a microthermistor array for converting temperature variation into an electrical signal, the array being composed of a plurality of microthermistors, each of the thermistors being adapted to output an electrical signal proportional to a temperature variation; a read-out integrated circuit operatively connected to the microthermistor array for receiving the electrical signal and converting it into an electronic output signal representative of the ridge and valley structure of a finger; and a substrate for supporting the read-out integrated circuit and the microthermistor array. The invention is based on microthermistor array. The ohmic resistance of these sensors varies strongly with temperature. The parameter directly measured in this case is the temperature-induced resistance variation of each individual microthermistor. Signals from each of the microthermistor part of the array represent the fingerprint pattern.< / PTEXT>

This invention provides a method apparatus for electrically connecting a semiconductor die, such as a power MOSFET, to a substrate on which the die is mounted, e.g., a lead frame, with a conductive strap, such that the connection is resistant to the shear stresses incident upon it with changes in temperature of the device. The method includes providing a conductive strap, and in one embodiment thereof, forming a recess in the top surface of the substrate. The bottom surface of a flange portion of the strap is attached to the floor of the recess such that the recess captures the flange and prevents relative horizontal movement of the flange and substrate with variations in the temperature of the device.Other embodiments include attaching the strap to the die and substrate with joints of a resilient conductive elastomer, and forming apertures in the strap and substrate that cooperate with a conductive joint material to reinforce the connection against temperature-induced shear forces.

The present invention consists of a method and system for compensating, over time and over an operating temperature range, for margin loss in a non-volatile memory (“NVM”) cell, which method comprises selection of a reference level based on temperature readings obtained from a temperature sensing element that is thermally coupled, directly or indirectly, to the NVM cell. The reference level may be selected from a group consisting of references levels of various types, or it may be obtained by adjusting the output of a single reference based on the temperature reading(s), or it may be obtained by utilizing pre-stored conversion data, which conversion data associates a given temperature reading with a corresponding temperature range that is, in turn, associated with a corresponding reference level. A pool of likewise reference cells may be provided, and the reference level may be selected from this pool, based on its association to the temperature reading. The pool of reference cells may consist of Program verify reference cells, or Erase verify reference cells.

The present invention consists of a method and system for compensating, over time and over an operating temperature range, for margin loss in a non-volatile memory (“NVM”) cell, which method comprises selection of a reference level based on temperature readings obtained from a temperature sensing element that is thermally coupled, directly or indirectly, to the NVM cell. The reference level may be selected from a group consisting of references levels of various types, or it may be obtained by adjusting the output of a single reference based on the temperature reading(s), or it may be obtained by utilizing pre-stored conversion data, which conversion data associates a given temperature reading with a corresponding temperature range that is, in turn, associated with a corresponding reference level. A pool of likewise reference cells may be provided, and the reference level may be selected from this pool, based on its association to the temperature reading. The pool of reference cells may consist of Program verify reference cells, or Erase verify reference cells.

A method and a device for eliminating or minimizing the sensitivity changes in a microphone due to temperature changes. The temperature-induced changes in the sensitivity can be caused by the changes in the sound-to-electrical signal transducer, in the microphone membrane, in the ASIC or other reasons. One or more temperature dependent components in the microphone or in a microphone module are used to offset the temperature-induced changes in the sensitivity. Sensitivity of a microphone is defined as the output voltage for a specific acoustic stimulus and load condition.

This invention is a storage device (cryocontainer) for the vitrification method of cryopreservation that uses shape memory materials to create a novel shape-shifting feature in which the relevant heat transfer zone of the cryocontainer can be thermally morphed between a shape conducive to biological specimen handling and to a shape conducive to rapid heat transfer. This feature utilizes the temperature induced phase transformation of shape memory materials. The temperature inducement occurs naturally within the normal temperature changes that occur during vitrification.

A T-RAM memory cell includes a temperature compensation device to adjust the gate-to-source voltage of an access transistor for the memory cell as a function of temperature so that the sub-threshold current of the transistor is insensitive to temperature variations. As a result, the sub-threshold current can be maintained slightly above the holding current of a thyristor used in the memory cell despite substantial temperature variations. In one embodiment, the temperature compensation device includes a current source directing a fixed current through a diode-connected transistor of the type used as the memory cell access transistor. Temperature induced changes in a reference voltage generated at the junction between the current source and the transistor therefore match the temperature induced changed in the sub-threshold current of the access transistor. As a result, the sub-threshold current of the access transistor can be made insensitive to temperature variations by applying the reference voltage to the gate or source of the access transistor.

An implantable pressure sensor system having a sensor assembly configured and adapted to measure pressure in a volume, the sensor assembly including at least a first MEMS pressure sensor, an application-specific integrated circuit (ASIC) having memory means, temperature compensation system, drift compensation system, a sensor catheter, and power supply means for powering the sensor assembly, the first MEMS pressure sensor having a pressure sensing element that is responsive to exposed pressure, the pressure sensing element being adapted to generate a pressure sensor signal representative of the exposed pressure, the temperature compensation system being adapted to correct for temperature induced variations in the pressure sensor signal, the drift compensation system being adapted to correct for pressure and temperature induced pressure sensor signal drift.

A side-hole optical cane for measuring pressure and / or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor, preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors, wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor, because temperature induces an equal shift in both the first and second wavelengths. Furthermore, the magnitude of these shifts can be monitored to deduce temperature, hence providing the side-hole cane additional temperature sensing capability that is unaffected by pressure. Additionally, the side-hole cane can be used to measure a differential pressure between a first pressure ported to the side-holes and a second external pressure.

A high speed optical communication system (>=10 Gbit / s) is compensated for temperature variation by providing it with one or more automatic dispersion compensation modules. Each module has an adjustable dispersion element, a data integrity monitor and a feedback network whereby the monitor adjusts the dispersion element to compensate for temperature variation. In a preferred embodiment the dispersion compensating modules comprise chirped fiber Bragg gratings in which the chirp is induced in the grating by passing a current along distributed thin film heaters deposited along the length of the fiber. The magnitude of the applied current determines the dispersion of the grating. A data integrity monitor is configured to sense the integrity of transmitted data and to provide electrical feedback for controlling the current applied to the grating.

A method and system of ultrasound imaging includes acquiring ultrasound channel data for a region-of-interest, determining an estimated size of a heat-affected region, identifying a first subset of the ultrasound channel data, and identifying a second subset of the ultrasound channel data. The method and system includes generating a pilot trace based on the first subset of ultrasound channel data and comparing the second subset of the ultrasound channel data to the pilot trace to determine delay errors for the second subset of the ultrasound channel data. The method and system includes determining that the heat-affected region has experienced a temperature-induced tissue change based on the delay errors and the estimated size of the heat affected region, and presenting information indicating that the heat-affected region has experienced the temperature-induced tissue change.

A method and apparatus for correction of temperature-induced variations in the analog output characteristics of a microbolometer detector in an infrared detecting focal plane array utilizing electronic means to correct for the temperature variation of the individual microbolometer detector. The electronic circuitry and associated software necessary for implementation is also described.

A nose cone formed from a shape memory alloy (SMA) having a recoverable strain of at least 2% collapses about the dome for storage, deploys at launch to protect the sensor dome and reduce drag during atmospheric flight and is shed to allow sensing for terminal maneuvers. The SMA is shape-set at elevated temperatures in its Austenite phase with a memorized shape having a radius of curvature greater than that of the sensor dome to reduce aerodynamic drag. The temperature is reduced and the SMA collapsed to conform to the curvature of the sensor dome within the recoverable strain for storage. A first mechanism is configured to return the collapsed SMA to its memorized shape at launch or prior to going supersonic. In one embodiment, the SMA is stored below its Martensite finish temperature in a temperature-induced Martensite phase in which case the mechanism heats the SMA above the Austenite finish temperature to return the material to its memorized shape. In another embodiment, the SMA is stored above its Austenite finish temperature in which case collapsing the SMA places the material in a strain-induced Martensite phase. The mechanism holds the collapsed SMA in place and the releases the stored energy allowing the SMA to return to the memorized shape.

Apparatus and methods that compensate for the thermally-induced drift of the resonance frequency of a closed-loop resonator include, in an exemplary embodiment, a waveguide-based Mach-Zehnder interferometer (MZI) and an overcoupled, waveguide-based microring resonator. The temperature-induced red-shifting ring resonance can be balanced by a spectral blueshift with temperature of the MZI. To stabilize the resonance of the ring at a given wavelength, the change in optical path lengths with temperature of the ring and the MZI should be equal and opposite. The interplay of nonlinear change in phase of ring resonator with temperature and linear change in phase of MZI with temperature, along with matching the period of this phase change, gives rise to perfect oscillation in the combined system resonance with temperature.

Vacuum insulating glass (VIG) units and edge seals for VIG units are provided. The VIG units include an edge seal that includes a viscous material, and is configured to allow the glass sheets to move laterally relative to one another when the glass sheets experience differential thermal strain and further configured such that viscous shear occurs within at least a portion of the viscous material when there is relative lateral movement between the glass sheets. The edge seals comprise a cavity that contains at least a portion of the viscous material, wherein at least a portion of a boundary defining the cavity is reversibly expandable and collapsible such that the viscous material and the cavity are configured to maintain volume compatibility when one or both of the viscous material and the cavity undergo a temperature-induced volume change.

The invention provides a method and apparatus to optimally estimate and adaptively compensate the temperature-induced frequency drift of a crystal oscillator in a navigational signal receiver. A Read-Write memory encodes two tables, one for looking up frequency drift values versus temperature readings and another one for valid data confirmation on the first table. The initially empty look-up table is gradually populated with frequency drift values while the receiver computes the frequency drift along with its position. During initial start of the receiver or re-acquisition of satellite signals, the stored frequency drift value corresponding to the current temperature is used. If no valid frequency drift value is available, the frequency drift value is computed based on the existing frequency drift values in the table. This invention reduces the Time-To-First-Fix (TTFF) of the receiver and enables the receiver to self-calibrate, thus no additional factory calibration would be necessary.

An implantable pressure sensor system having a sensor assembly configured and adapted to measure pressure in a volume, the sensor assembly including at least a first MEMS pressure sensor, an application-specific integrated circuit (ASIC) having memory means, temperature compensation system, drift compensation system, and power supply means for powering the sensor assembly, the first MEMS pressure sensor having a pressure sensing element that is responsive to exposed pressure, the pressure sensing element being adapted to generate a pressure sensor signal representative of the exposed pressure, the temperature compensation system being adapted to correct for temperature induced variations in the pressure sensor signal, the drift compensation system being adapted to correct for pressure and temperature induced pressure sensor signal drift.

A porous polymer separator for use in a lithium ion battery is formed by a temperature-induced phase separation method. The porous polymer separator includes a polymer matrix having opposed major faces and a network of pore openings that extends between the major faces and permits intrusion of a lithium-ion conducting electrolyte solution. As part of the temperature-induced phase separation method, a single phase polymer solution that includes a polymer material dissolved in a miscible mixture of a real polymer solvent and a polymer non-solvent is prepared at an elevated temperature above room temperature. A film is then formed from the single phase polymer solution and cooled to phase-separate the polymer material into a solid polymer precipitate. Additional polymer non-solvent is then used to remove the real polymer solvent from the solid polymer precipitate followed by drying.

Transmissions over a unidirectional optical fiber coupling multiple nodes are compensated for temperature-induced effects. A round-trip delay time is determined for a signal sent from a first node to travel around the unidirectional optical fiber loop and be received back at the first node. That measured round-trip delay time is then used to account for temperature-induced effects on signal transmissions over the unidirectional optical fiber loop. This temperature compensation is particularly beneficial in applications that require a high level of timing accuracy.

A method and a voltage-controlled oscillator provide an output signal with a frequency within one of a plurality of frequency bands, while reducing or eliminating temperature-induced band-switching or other drifts in operating frequency. The band-switching is reduced or eliminated by providing a circuit that adjusts a tuning sensitivity according to a calibration performed under test conditions. For example, such a voltage-controlled oscillator may include (a) a digitally controlled variable current source for providing a first control current to select one of the frequency bands for the voltage-controlled oscillator; (b) a variable transconductance circuit providing a second control current to compensate a variation in operating frequency; and (c) a control circuit for varying the frequency of the output signal in accordance with the first and second control signals. The variable transconductance circuit may be programmable by selectively activating elements of an array of varactor circuits, according to a capacitance associated with each varactor circuit. The capacitance associated with each varactor circuit is binary weighted.

Transmission spectrometers require low levels of background light so that the signal to noise ratio is increased, and also require stable performance over wide temperature ranges. Light reflected by the transmission grating can result in increased background levels. One approach to reducing the background level is to orient the transmissive diffraction grating so that light reflected by the grating is reflected out of the diffraction plane. The temperature-induced wavelength drift of a transmission spectrometer can be due to the frame upon which the transmission grating is mounted. The wavelength drift is reduced by allowing the thermal expansion of the grating to be independent of the frame.