115 results about "Thermal diode" patented technology

A system and method for evaluating the thermal bond between a heat-producing device and a heat-absorbing apparatus. The heat-producing device may be a CPU, such as an INTEL PENTIUM microprocessor, and the heat-absorbing apparatus may be a heat sink. The two may be joined with a heat-conducting substance such as thermal grease or adhesive. In one exemplary embodiment, the heat-producing device is operated at a first power level, a first temperature measurement is then taken, the device is operated at a second power level, and then a second temperature measurement is then taken. The thermal resistance is then calculated, which may involve subtracting the second temperature from the first, and may involve dividing by the power level. The first power level may be full power, and the second power level may be near zero. The first temperature may be measured when equilibrium temperatures have been reached, and the second temperature may be measured a predetermined amount of time after the second power level is initiated, which may be just enough time for the temperatures of the CPU and the heat sink to equalize. The CPU may perform the calculations, and the temperature may be measured with an on-board thermal sensor which may be a thermal diode.

A silicon carbide power device includes a junction field effect transistor and a protective diode, which is a Zener or PN junction diode. The PN junction of the protective diode has a breakdown voltage lower than the PN junction of the transistor. Another silicon carbide power device includes a protective diode, which is a Schottky diode. The Schottky diode has a breakdown voltage lower than the PN junction of the transistor by adjusting Schottky barrier height or the depletion layer formed in the semiconductor included in the Schottky diode. Another silicon carbide power device includes three protective diodes, which are Zener diodes. Two of the protective diodes are used to clamp the voltages applied to the gate and the drain of the transistor due to surge energy and used to release the surge energy. The last diode is a thermo-sensitive diode, with which the temperature of the JFET is measured.

A system and method for evaluating the thermal bond between a heat-producing device and a heat-absorbing apparatus. The heat-producing device may be a CPU, such as an INTEL PENTIUM microprocessor, and the heat-absorbing apparatus may be a heat sink. The two may be joined with a heat-conducting substance such as thermal grease or adhesive. In one exemplary embodiment, the heat-producing device is operated at a first power level, a first temperature measurement is then taken, the device is operated at a second power level, and then a second temperature measurement is then taken. The thermal resistance is then calculated, which may involve subtracting the second temperature from the first, and may involve dividing by the power level. The first power level may be full power, and the second power level may be near zero. The first temperature may be measured when equilibrium temperatures have been reached, and the second temperature may be measured a predetermined amount of time after the second power level is initiated, which may be just enough time for the temperatures of the CPU and the heat sink to equalize. The CPU may perform the calculations, and the temperature may be measured with an on-board thermal sensor which may be a thermal diode.

A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder. A plurality of thermal stages is stacked along an axial direction between a cold side and a hot side. A heat exchanger includes a cylindrical stator positioned at and in thermal communication with the cold side or the hot side of the plurality of thermal stages. A cylindrical rotor is spaced from the cylindrical stator by a cylindrical gap. The cylindrical rotor is configured to rotate relative to the cylindrical stator about a rotation axis. A shearing liquid zone is defined between a surface of the cylindrical stator that faces the cylindrical gap and a surface of the cylindrical rotor that faces the cylindrical gap when the cylindrical gap is filled with a liquid.

A composite VDMOS device possessing a temperature sampling and over-temperature protection function belongs to the power semiconductor device field. In the invention, a VDMOS device, a polysilicon thermal diode and an over-temperature protection circuit are integrated. Through using a negative temperature characteristic of forward voltage drop of the polysilicon thermal diode, the polysilicon thermal diode is made on an insulating layer of a VDMOS device surface so as to realize sampling of a VDMOS device operating temperature. Based on a temperature sampling signal of the polysilicon thermal diode, the over-temperature protection circuit carries out partial pressure to a gate input voltage Vin of the whole composite VDMOS device so as to obtain a gate control voltage VG of the VDMOS device. Therefore, the over-temperature protection can be performed to the VDMOS device, which is characterized by: when the operating temperature of the VDMOS device reaches TH, turning off the VDMOS device; when the internal temperature drops to TL after the VDMOS device is turned off, starting the VDMOS device, wherein temperature return difference can be represented as a following formula: Delta T=TH-TL. By using the composite VDMOS device of the invention, the accurate sampling and the over-temperature protection can be performed to the VDMOS device so that thermal failure of the device can be avoided and a service life of the device can be prolonged. A structure is simple and sampling accuracy is high. The device is compatible with a VDMOS device technology. The device is monolithic and has many other advantages.

A method and a reference circuit for bias current switching are provided for implementing an integrated temperature sensor. A first bias current is generated and constantly applied to a thermal sensing diode. A second bias current is provided to the thermal sensing diode by selectively switching a multiplied current from a current multiplier to the thermal sensing diode or to a load diode. The reference circuit includes a reference current source coupled to current mirror. The current mirror provides a first bias current to a thermal sensing diode. The current mirror is coupled to a current multiplier that provides a multiplied current. A second bias current to the thermal sensing diode includes the first bias current and the multiplied current from the current multiplier. The second bias current to the thermal sensing diode is provided by selectively switching the multiplied current between the thermal sensing diode and a dummy load diode.

A mechanism for utilizing a single set of one or more thermal sensors, e.g., thermal diodes, provided on the integrated circuit device, chip, etc., to control the operation of the integrated circuit device, associated cooling system, and high-frequency PLLs is provided. By utilizing a single set of thermal sensors to provide multiple functions, e.g., controlling the operation of the integrated circuit device, the cooling system, and the PLLs, silicon real-estate usage is reduced through combining circuitry functionality. Moreover, the integrated circuit device yield is improved by reducing circuitry complexity and increasing PLL robustness to temperature. Furthermore, the PLL circuitry operating range is improved by compensating for temperature.

An electronic device testing apparatus is described that includes a temperature measurement device for measuring a temperature of an IC device based on a voltage of a thermal diode provided inside the IC device, a temperature sensor and a temperature applying device provided to a pusher, and a temperature control portion for calculating a correction value from a difference of a measurement temperature of a predetermined IC device by the temperature measurement device and that by the temperature sensor. A temperature of the IC device to be tested is measured by the temperature measurement device at an actual operation, and the temperature applying device is controlled based on the obtained measurement temperature and the correction value calculated by the temperature control portion.

A method for controlling the rotating speed of a fan is disclosed. The method includes the steps of: reading a standard temperature Tc of a central processing unit (CPU); reading a thermal diode's temperature Td and a system ambient temperature Ta; comparing Td with a minimum temperature Tl, such that the fan begins processing the heat of the CPU begins; if Td>Tl, increasing pulse-width modulation (PWM) duty cycle of the fan to 100%; if Td<=Tl, comparing a critical temperature T0 with Ta; if Ta>T0, increasing PWM fan duty cycle to 100%; if Ta<=T0, setting the fan duty cycle at 40%; sending the PWM fan duty cycle to a fan speed controller.

A far-field radiative thermal rectification device uses a phase change material to achieve a high degree of asymmetry in radiative heat transfer. The device has a multilayer structure on one side and a blackbody on other side. The multilayer structure can consist of a transparent thin film of KBr sandwiched between a thin film of VO2 and a reflecting layer of gold. When VO2 is in its insulating phase, the structure is highly reflective due to the two transparent layers on highly reflective gold. When VO2 is in the metallic phase, Fabry-Perot type of resonance occurs and the tri-layer structure acts like a wide-angle antireflection coating achieved by destructive interference of partially reflected waves making it highly absorptive for majority of spectral range of thermal radiation. The instant structure can form the active part of a configuration that acts like a far-field radiative thermal diode.

A circuit for sensing on-die temperature at multiple locations using a minimum number of pins is described. Thermal diodes coupled to pins are placed on a die to measure the temperature at various die locations. Voltage is applied to the pins to determine the temperature at each given diode location. The polarity of the voltage applied across the pins determines what diodes are selected for measurement.

A heat pipe for horizontal arrangement, which belongs to a heat transfer element, comprises a pipe body and a medium fluid in the pipe body, wherein the pipe body comprises an evaporation segment, a heat insulation segment and a condensation segment, which are communicated with each other; and heat-dissipating fins are arranged on the outer circumference of the condensation segment. The condensation segment of the heat pipe is inclined upwards by an angle beta relative to the evaporation segment and the heat insulation segment, and a liquid absorption net is arranged on the inner walls of the evaporation segment and the heat insulation segment of the pipe body. When the heat pipe works normally, the medium fluid is repeatedly circulated in the heat pipe to carry out rapid heat exchange. When the temperature of the condensation segment is higher than the temperature of the evaporation segment, the inclination angle of the condensation segment can allow the gas to gather at the condensation segment and the liquid to gather at the evaporation segment to prevent the occurrence of heat blockage due to the flowing and circulation of the medium in the pipe and prevent reverse heat transfer, so that the heat pipe can achieve one-way heat transfer function of one-way thermal diode by injecting only one medium. The heat pipe has the advantages of improved heat transfer efficiency, reduced processing steps and saved manufacture material.

The present invention provides a solar energy heat utilizing system combining thermal diode and phase-change energy-storing materials, it is characterized by it combines the thermal diode technology and the phase-change energy-storing technology, at the same time utilizes them in solar energy heat utilization to provide life hot water for people. When solar radiation is absorbed by heat-collecting sheet, the temperature of heat-collecting sheet one side is increased swiftly, the temperature of phase-change materials in heat-storing device is relative lower, so the solar energy heat quantity is transmitted into heat-storing device through thermal diode to make phase-change materials absorb heat and unfreeze and store heat quantity; when life hot water is needed, tap water flows over the heat transferring coil pipe in phase-change materials, and absorbs heat quantity for warming-up. The system has simple structure, it is easy to be combined with buildings, due to the utilization of thermal diode technology and the phase-change energy-storing technology, the heat-collecting performance and thermal insulation performance of the system are improved greatly. Compared with all-glass vacuum tube solar water heating system, the system has characteristics of no freezing, bearing more, fast start, high sensitivity and fast heat transfer speed.

A thermal sensing system includes a circuit having a layout including standard cells arranged in rows and columns. First and second current sources provide first and second currents, respectively. The thermal sensing system includes thermal sensing units, first and second switching modules, and an analog to digital converter (ADC). Each thermal sensing unit is configured to provide a voltage drop dependent on a temperature at that thermal sensing unit. The first switching module is configured to select one of the thermal sensing units. The second switching module includes at least one switch controllable by a control signal. The at least one switch is configured to selectively couple the thermal sensing units, based on the control signal, to one of the first and second current sources, via the first switching module. The ADC is configured to convert an analog voltage, provided by the selected thermal sensing unit, to a digital value. The invention also provides a small area high performance cell-based thermal diode.

A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder with a plurality of magneto-caloric stages. Each of the plurality of magneto-caloric stages has a respective Currie temperature. The magneto-caloric cylinder has a length along an axial direction. The plurality of magneto-caloric stages is distributed along the length of the magneto-caloric cylinder. A plurality of thermal stages also has a length along the axial direction. The length of the plurality of thermal stages is less than the length of the magneto-caloric cylinder. The magneto-caloric cylinder is received within the plurality of thermal stages such that the magneto-caloric cylinder is movable along the axial direction relative to the plurality of thermal stages.

A mechanism for utilizing a single set of one or more thermal sensors, e.g., thermal diodes, provided on the integrated circuit device, chip, etc., to control the operation of the integrated circuit device, associated cooling system, and high-frequency PLLs is provided. By utilizing a single set of thermal sensors to provide multiple functions, e.g., controlling the operation of the integrated circuit device, the cooling system, and the PLLs, silicon real-estate usage is reduced through combining circuitry functionality. Moreover, the integrated circuit device yield is improved by reducing circuitry complexity and increasing PLL robustness to temperature. Furthermore, the PLL circuitry operating range is improved by compensating for temperature.

A design structure for an apparatus for utilizing a single set of one or more thermal sensors, e.g., thermal diodes, provided on the integrated circuit device, chip, etc., to control the operation of the integrated circuit device, associated cooling system, and high-frequency PLLs, is provided. By utilizing a single set of thermal sensors to provide multiple functions, e.g., controlling the operation of the integrated circuit device, the cooling system, and the PLLs, silicon real-estate usage is reduced through combining circuitry functionality. Moreover, the integrated circuit device yield is improved by reducing circuitry complexity and increasing PLL robustness to temperature. Furthermore, the PLL circuitry operating range is improved by compensating for temperature.

A magneto-caloric thermal diode assembly includes a plurality of elongated magneto-caloric members. Each of a plurality of thermal stages includes a plurality of magnets and a plurality of non-magnetic blocks distributed in a sequence of magnet then non-magnetic block along a transverse direction. The plurality of thermal stages and the plurality of elongated magneto-caloric members are configured for relative motion along the transverse direction. The plurality of magnets and the plurality of non-magnetic blocks are spaced along the transverse direction within each of the plurality of thermal stages. Each of the plurality of magnets in the plurality of thermal stages is spaced from a respective non-magnetic block in an adjacent thermal stage towards a cold side thermal stage along the lateral direction and is in conductive thermal contact with a respective non-magnetic block in an adjacent thermal stage towards a hot side thermal stage along the lateral direction.

A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder with a plurality of magneto-caloric stages. A length of one of the plurality of magneto-caloric stages is different than a length of another of the plurality of magneto-caloric stages. Each of a plurality of thermal stages includes a plurality of magnets and a non-magnetic ring. The plurality of magnets is distributed along a circumferential direction within the non-magnetic ring in each of the plurality of thermal stages. The length of each of the plurality of thermal stages corresponds to a respective one of the plurality of magneto-caloric stages.