A miniature thermo-photovoltaic (TPV) device for generation of electrical power for use in portable electronic devices. A TPV power source is constructed to provide a heat source chemical reactor capable of using various fuels, such as liquid hydrocarbons, including but not limited to propane, LPG, butane, alcohols, oils and diesel fuels to generate a source of photons. A reflector dish guides misdirected photon energy from the photon source toward a photovoltaic array. A thin transparent protector sheet is disposed between the photon source and the array to reflect back thermal energy that cannot be converted to electricity, and protect the array from thermal damage. A microlens disposed between the protector sheet and the array further focuses the tailored band of photon energy from the photon source onto an array of photovoltaic cells, whereby the photon energy is converted to electrical power. A heat recuperator removes thermal energy from reactor chamber exhaust gases, preferably using mini- or micro-bellows to force air and fuel past the exhaust gases, and uses the energy to preheat the fuel and oxidant before it reaches the reactor, increasing system efficiency. Mini- or micro-bellows force ambient air through the system both to supply oxidant and to provide cooling. Finally, an insulator, which is preferably a super insulator, is disposed around the TPV power source to reduce fuel consumption, and to keep the TPV power source cool to the touch so it can be used in hand-held devices.
The present invention is an apparatus and method for controlling the temperature of a heat generating device. The invention is particularly adaptable to controlling the temperature of an integrated circuit under test. In one embodiment the invention involves the use of a bellows having a heat slug disposed at one end that is adapted to engage a surface of the heat generating device. The bellows is compliant and includes a cavity containing a heat transfer medium. The bellows cavity is in fluid communication with a heat transfer medium reservoir. Heat is transferred from the heat generating device by engaging the heat slug with a surface of the heat generating device and applying a force to the bellows. The compliant nature of the bellows provides the temperature control apparatus with a self-planarizing feature that maximizes the contact surface area between the heat slug and heat generating device.
A microthermophotovoltaic (micro-TPV) system is a novel micro power device. The system fully utilizes the high surface-to-volume ratio of a microcombustor, and is able to deliver and electrical power output of 0.5-10 W in a package of the order of centimeters. The system comprises mainly a combustor-emitter, a filter, a photovoltaic (PV) cell array, and cooling fins. The combustor-emitter functions to convert chemical energy into radiative heat energy. The filter is able to recycle a large part of the unusable energy that cannot be converted into electricity by the PV cell array. The PV cell array is used to convert radiative heat energy into electricity. The system has no moving parts. Its fabrication and assembly are relatively easy. As a result, it can be readily used as a power source of micro mechanical devices and portable devices, in which convenience and low cost reliability and ease of maintenance are the key factors of consideration.
The generator includes: elements (4, 10) for generating a magnetic field in a first direction, a hot source (6) and a cold source (8) creating a temperature gradient (.gradient.T) in a second direction substantially perpendicular to the first direction, and at least one element (2; 14) having thermoelectric conversion properties, disposed in a plane substantially perpendicular to the direction of the temperature gradient (.gradient.T). The magnetic field generated is a field of traveling waves moving in the second direction. Each element having thermoelectric conversion properties has a continuous form in the plane perpendicular to the second direction.
Surveillance systems of this invention incorporate a charge coupled device image sensor with an illumination source that is made of an emitter which concentrates its optical output in a narrow band at or about the peak optical response of the photoconverter being used. Where a silicon imaging sensor is being used, the illumination system can comprise an emitter made of a rare earth oxide, such as ytterbium oxide, in the form of a filamentary network and fuel to energize the emitter. Different emitters can be employed to achieve the optimal radiant energy for any type of photoconverter device, including those based on silicon, germanium, indium gallium arsenide, and gallium antimonide. These surveillance systems may be applied in a number of specialized applications, such as, for example, in the covert surveillance of commercial, industrial, residential, or military sites, or any site in which the visible illumination of the surveillance area is undesirable. Because the emitters of the present invention emit radiation at or about the peak optical response wavelengths of the imaging sensors, the surveillance systems of the present invention are also advantageous in situations in which efficient energy consumption is important.
A thermophotovoltaic power generating apparatus has a combustor for burning a fuel upon supply of the fuel and air, an emitter heated by passage therein of combustion gas produced in the combustor, and a photoelectric conversion element that converts light radiated from the emitter into electric power, the combustor being provided between the emitter and the conversion element. Preferably, the emitter is disposed above the combustor, and the photoelectric conversion element is disposed below the combustor. With this structure, combustion gas does not reside in the combustion chamber, but is discharged via the emitter disposed above the combustor. Combustion becomes stable, and the emitter is efficiently heated, so that energy radiated from the emitter surface increases.
