Abstract: An improved thermoelectric power generation system utilizes rotary thermoelectric configurations to improve and increase thermal power throughput. These systems are further enhanced by the use of hetrostructure thermoelectric materials, very thin plated materials, and deposited thermoelectric materials, which operate at substantially higher power densities than typical of the previous bulk materials. Several configurations are disclosed.

Abstract: A nondestructive inspection device (or method) is basically configured such that a laser beam (1300 nm) is irradiated on a surface (or back) of a semiconductor device chip to scan. Due to irradiation of the laser beam, a defect position is heated to cause a thermoelectromotive current, which induces a magnetic field. A magnetic field detector such as SQUID detects a strength of the magnetic field, based on which a scan magnetic field image is produced. A display device superimposes the scan magnetic field image on a scan laser microphotograph on a screen, so it is possible to perform defect inspection on the semiconductor device chip. Incidentally, a semiconductor device wafer is constructed to include a thermoelectromotive force generator and its wires, which are electrically connected to first-layer wires. By irradiation of the laser beam on the thermoelectromotive force generator, it is possible to detect a short-circuit defect, which lies between the first-layer wires.

Abstract: A plurality of n-type bar-shaped devices (51) consisting of an n-type thermoelectric semiconductor and a plurality of p-type bar-shaped devices (52) consisting of a p-type thermoelectric semiconductor are regularly disposed or fixed through an insulating layer (50) to form a thermoelectric device block (53). End portions of the n-type bar shaped device (51) and the p-type bar-shaped device (52) are connected with an interconnection conductor (58a) on an upper surface (53a) and a lower surface (53b), which will be interconnecting end faces of the thermoelectric device block (53), to form a plurality of thermocouples connected in series.

Abstract: A plurality of n-type bar-shaped devices (51) consisting of an n-type thermoelectric semiconductor and a plurality of p-type bar-shaped devices (52) consisting of a p-type thermoelectric semiconductor are regularly disposed or fixed through an insulating layer (50) to form a thermoelectric device block (53). End portions of the n-type bar shaped device (51) and the p-type bar-shaped device (52) are connected with an interconnection conductor (58a) on an upper surface (53a) and a lower surface (53b), which will be interconnecting end faces of the thermoelectric device block (53), to form a plurality of thermocouples connected in series.

Abstract: Electric power is generated downhole in a well using a thermoelectric device. A temperature gradient or differential .DELTA.T present in the well is applied to the thermoelectric device to produce a voltage potential across the output terminals of the device. The thermoelectric device includes a first thermocouple coupled to a heat source and a second thermocouple coupled to a heat sink source. The electric power generated by the thermoelectric device is used to recharge battery packs located downhole or to power electrical devices or systems.

Abstract: A thermionic paired tube bank (100) designed for use as a tubular heat exchanger for generating electricity, preferably heated by combustion products after they leave the combustor of a power plant but before they enter the turbine or steam generator portion of the power generation system. In this case the thermionics act as a topping cycle to increase the overall electrical generation efficiency. The heat could also be supplied by the products of combustion as they leave the gas turbine or steam generator in which case the thermionics would act as a bottoming cycle. The thermionic paired-tube bank comprises a plurality of paired-tube thermoelectric couples (50) and a plurality of electrical connections (66, 68).

Abstract: On a top surface of a substrate, a first and a second electrode are formed. A p-type semiconductor film is formed over substantially the entire exposed area on the top surface of the substrate and over the first electrode. An n-type semiconductor film is also formed over substantially the entire surface, but does not cover the first electrode, the p-type semiconductor film and the second electrode. A junction surface between the p-type and n-type semiconductor films extends over substantially the entire substrate, thereby providing a thermoelectric device which can cool or heat a wide surface area. The inclusion of the junction surface between p-type and n-type films, which extends over substantially the entire surface of the substrate, provides a unit whose top surface serves as a heat-absorbing portion and whose bottom surface serves as a heat-releasing portion.

Abstract: One of a heat-absorbing-side thermal conductor and a heat-dissipating-side thermal conductor is substantially in a form of a single piece. Plural groups of thermoelectric elements are arranged relative to the single-piece thermal conductor. Corresponding to the plural groups of thermoelectric elements, the other one of the heat-absorbing-side thermal conductor and the heat-dissipating-side thermal conductor is arranged in a form divided into a like number of pieces.

Abstract: The invention refers to a thermoelectric generator unit comprising a plurality of thermoelectric elements (1) of alternately p and n character and electrically series connected by means of metal connector members (2), the elements having essentially cylindrical shape.

Abstract: A thermoelectric module with a plurality of electricity generating units each having a first end and a second end, the units being arranged first end to second end along an in-line axis. Each unit includes first and second elements each made of a thermoelectric material, an electrically conductive hot member arranged to heat one side of the first element, and an electrically conductive cold member arranged to cool another side of the first element and to cool one side of the second element. The hot member, the first element, the cold member and the second element are supported in a fixture, are electrically connected respectively to provide an electricity generating unit, and are arranged respectively in positions along the in-line axis. The individual components of each generating unit and the respective generating units are clamped in their in-line positions by a loading bolt at one end of the fixture and a stop wall at the other end of the fixture.

Abstract: A microfabricated thermopile optimized as a differential temperature sensor provides differential temperature sensing between opposite edges of the device. A plurality of the thermopile sensors are stacked to increase the number of couples possible with an attendant increase in sensitivity.

Abstract: The present invention provides an alkali metal thermal to electric conversion cell having radially projecting beta-alumina type solid electrolyte elements and a central heat input region.

Abstract: A subsea thermoelectric generator has a plurality of flat thermoelectric modules attached concentrically to the outside wall of an undersea line in which petroleum products extracted from a subsea drilling well circulate. The thermoelectric modules are disposed in flat-bottomed pans machined into the outside wall of the line. The pans are sealed by lids made of heat-conducting material and in thermal contact with the thermoelectric modules. Each lid defines, with the walls of the corresponding pan, a peripheral sealed chamber. The various chambers in the pans communicate with each other through passages provided in partitions that separate the pans and are filled with a soft (compliant), preferably non-heat-conducting, resin. At least one of the pans is provided with an orifice closed by a sealed deformable element.

Abstract: A thermoelectric radiator for generating a direct current while providing at least a portion of the necessary cooling is formed with a first and second plurality of interdigitated thermoelectric lamella which are electrically joined and are connected to the positive and negative portions of the electrical system. The result is direct current flow when a heated coolant is passed over the lamella.

Abstract: A thermoelectric device fabricated of at least two dissimilar thermoelements and at least one of the thermoelements has a conductor in parallel therewith increasing the Figure of Merit. The thermoelements are also surrounded by a conductor along the leg lengths thereby simplifying the manufacturing process.

Abstract: A thermoelectric module includes a switching circuit for switching the connection between a first thermoelectric element and a second thermoelectric element between series connection and parallel connection, a voltage detecting circuit for controlling the switching circuit by detecting the voltage of the second thermoelectric element, and a storage battery circuit for storing electricity utilizing the voltages generated by the first thermoelectric element and the second thermoelectric element connected by the switching circuit. A voltage generated from an applied temperature difference is detected by the voltage detecting circuit. If there is a sufficient temperature difference, the first thermoelectric element and second thermoelectric element are connected in parallel by the switching circuit to charge the electricity in the storage battery circuit using the doubled current.

Abstract: A thermoelectric generator system including a refrigerator of the of the absorption type having no moving parts and operating with ammonia, water and hydrogen to extract heat from a heat source and discharge heat from an absorber and having at least one thermocouple positioned to intercept heat flow from the heat source to the boiler and/or from the condenser to the evaporator. The system is arranged such that a boiler from one system absorbs heat discharged from the absorber of one or more other identical systems so that systems can be ganged together to produce a combine system having increased efficiency.

Abstract: The invention encompasses a torus formed by heated and cooled junctions of dissimilar metals such as copper and nickel to generate a low voltage current and form an electrical path of greatly enhanced conductivity wherein a greater current flow may be induced to form a stronger magnetic field. Current at higher voltage may be incrementally removed by magnetic field arrangements to act as magnetic variable switches while at the same time the magnetic field is contained and current also flows through the torus.

Abstract: A heater mechanism incorporating a thermoelectric converter for use with a self-powered, solid, liquid or gaseous fueled, heater. During operation of the heater mechanism the thermoelectric converter supplies sufficient electrical power to (a) sustain the heater in operation, (b) maintain the starter battery at full charge, and (c) provide auxiliary power to remove and transport heat to desired locations away from the heater. The converter is a highly compact design (high power output per unit volume of space) and lends itself to high volume (mass production) and automated assembly techniques to produce it inexpensively. The thermoelectric converter is made of fewer components than prior art devices. A number of components in the thermoelectric stack serve dual or even multi-functions. The thermoelectric stack components are bonded or mounted together in such a manner as to permit handling as a unit.

Abstract: A thermoelectric element sheet includes at least two layered structures having a plurality of thermoelectric elements which are arranged between insulating films. In each layered structure the thermoelectric semiconductors are arranged in pairs and electrodes connect the thermoelectric semiconductors of each pair to provide a plurality of structural units. Further electrodes connect the structural units. The thermoelectric element sheet can be used in thermoelectric energy conversion systems which depend on the Seebeck, Peltier or Thomson effect to convert thermal energy to electrical energy or vice versa.

Abstract: Multijunction thermal converters are formed in an integral multifilm membrane form over a through opening in a nonmagnetic, dielectric substrate. Through the use of conventional photolithographic and etching techniques, very compact, rugged and precise integrated structures are formed to include either single linear elongate heater elements, bifilar or trifilar heater elements, and multijunction thermopiles at reasonable cost. Disposition of the heater element and hot junctions of the thermopiles over a through opening in the substrate, with the cold junctions of the thermopiles disposed over the substrate thickness, enables the heating element to provide a substantially isothermal uniform heating of the thermocouple hot junctions to obtain high thermal efficiency and reduce Thompson and Peltier heating effects. Forming the essential elements into an integrated multifilm membrane also makes possible minimization of interconnections between the elements, and this results in minimized reactance.

Abstract: A low voltage high amperage thermopile generating and electron storage unit is disclosed wherein current is formed by heating and cooling alternate junctions of dissimilar metals arranged in a circular fashion and may be enhanced with an electrical flux pump. Current may be withdrawn using an ultra fast thermopile type switch to connect to an electrical load source.

Abstract: In the conventional thermoelectric conversion module, P-type thermoelectric semiconductor chips and N-type thermoelectric semiconductor chips are alternately arranged in both the longitudinal and the transverse directions. Consequently, assembling work is complicated and there arises the problem in quality that erroneous types of chips are arranged. In the present invention, therefore, each of either rows of chips or columns of chips is constituted by thermoelectric semiconductor chips of the same type, thereby to improve assembling workability as well as to prevent erroneous arrangement. Furthermore, as a preferred fabricating method, bar-shaped thermoelectric semiconductors are used and are jointed to one substrate and then, are electrically disconnected between the leads.

Abstract: A thermopile 30 comprises a stacked assembly of bimetallic layers in which there is full conductor interface contact over the distance separating hot and cold surfaces 31, 32. The assembly may include dielectric layers forming a capacitor stack. A.C. current through the stack is matched in strength to the Seebeck-generated thermoelectric current circulating in each bimetallic layer. The resulting current snakes through the stack to cause Peltier cooling at one heat surface and heating at the other. A.C. operation at a kilocycle frequency enhances the energy conversion efficiency as does heat flow parallel with the junction interface.

Abstract: A method of manufacturing a thermoelectric device including the steps of printing a patterned mask on both sides of a strip of copper foil, shielding one side and plating a pattern of nickel on the other side, removing the shield, securing the foil to a flexible film and etching copper from predesignated areas, creating the thermoelectric device.

Abstract: Thermoelectric heat pumps using recuperative heat exchange are described. These devices use sets of thermocouples (thermoelectric couples) arranged side-by-side to form a plate. The plate is positioned in a fluid-containing vessel and heat exchanging fluid is flowed down one side of the plate and up the other side. In these devices the heat flow, and thus the driving thermal gradient on each thermoelectric couple in the device, is in a direction from one side of the plate to the other side, i.e., other than the direction of the device's working thermal gradient, which is the direction of the flow of fluid. Generally these two directions (driving gradient on the thermoelectric couples and fluid flow-working thermal gradient) are essentially orthogonal to each other.

Abstract: Disclosed are integrity-enhanced thermoelectric devices and methods of their preparation. Such devices have the following characteristics: (1) there is, on average, no greater than about 10% incidence of function loss (failure) of the device on application to the device of a substantial impact or distortion force or corrosion exposure, and (2) the device have at least about 85% of the thermal performance of thermoelectric devices without integrity enhancement (i.e., thermal conductivity across the integrity-enhanced devices is significantly less than 0.0021 Cal-Cm/Cm.sup.2 Sec .degree.C., and is less than or equal to about 0.0015 Cal-Cm/Cm.sup.2 Sec .degree.C.; empirically expressed as maintenance of at least a 40.degree. C. temperature differential over the intra-plate distance which is about 3/16 to about 1/4 of an inch.).

Abstract: A thermoelectric device has hot and cold sides. The hot and cold sides include a plate of insulation material having "peanut" or rectangularly shaped tabs forming hot and cold side tab patterns. The tabs have circular or polygonal shaped pockets adjacent opposing ends of the tabs. Legs of p-type and n-type semiconductor material are attached in opposing end pockets of the tabs. Spade connectors are attached to end tabs of the cold side plate for connection to a dc source of power. The legs are vibrated into the pockets of one side (either the hot or cold side) and the tabs of the other side are positioned to opposing ends of the tabs of the other side (either the cold or hot side).

Abstract: A new and improved semiconductor thermoelectric device which could be used either as a thermoelectric cooler or as a thermopile heat sensor with high output voltage. This invention comprises an array of thermocouples fabricated on a semiconductor substrate. The thermocouples comprise segments of tantalum and segments of conductively doped polysilicon as two electric conductor materials of different thermoelectric properties which are buried between two layers of oxide. A layer of metal as a heat collector covers the surface of the thermopile and distributes heat from a nearby heat source.

Abstract: Thermopile has a plurality of reference junctions and a plurality of measurement thermocouple junctions connected electrically alternately in series on a dielectric support. Each reference junction has thereover a first medium which is nonthermally responsive and each measurement junction has thereover a second medium which is thermally responsive. The first and second mediums occupy areas which are arranged in a checkerboard pattern, the reference junctions under areas occupied by said first medium each being electrically connected directly to a measurement thermocouple under an area occupied by said second medium.

Abstract: An improved thermoelectric device and fabrication process wherein in a first embodiment strips of conductive material are attached to corresponding strips of adhesive material and first and second patterned arrays of tabs are struck from the strips onto the adhesive strips. In a second embodiment strips of conductive material are blanked to form the first and second patterned arrays of tabs and substantially simultaneously therewith the arrays of tabs are partially returned to their strips which now serve as support frames for the tab arrays. The array of tabs have either flat rectangular surfaces or flat peanut shaped surfaces with or without round shaped pockets adjacent to each end. Round pockets are used to receive legs of thermoelectric material of any shape without orientation. The first and second patterned tab arrays are attached to plates of insulation material and the adhesive strips or the strip frames removed, as applicable, to form first and second side plates.

Abstract: In order to increase the thermoelectromotive force delivery by a thermoelectric element as a whole or regulate the temperature coefficient of such thermoelectromotive force, n-type semiconductive ceramic members and p-type semiconductive ceramic members are assembled to form such element and are electrically connected with each other. The n-type and p-type semiconductive ceramic members are provided in the form of plate members, which are stacked so as to be interconnected by insulating layers and conductor layers. The insulating and conductor layers are provided on opposite surfaces of adjacent plate members by thick film printing and baking performed thereafter.

Abstract: Disclosed is a thermopile improved in its measurement sensitivity and manufacturing cost, which comprises a pillar-shaped substrate having a side extending in the parallel direction to an incident light to be measured so as not to be irradiated with the incident light, and first and second thermoelectric material layers arranged alternately on the side of the pillar-shaped substrate along the extending direction of the side of said pillar-shaped substrate.

Abstract: A thermoelectric heat pump or power source device is provided with P-type and N-type elements made of either thin films or thick films for use on flexible or nonflexible substrates. For flexible units the film type elements are formed on substrates of such flexible, electrically insulation material as, for example, MYLAR and TEFLON; while for inflexible units the elements are formed on substrates of such materials as, for example, Beryllia, Alumina, ceramics, or plastics. Further, the elements are patterned on the different substrates for particular usages. For example, radial element patterns used for cooling hot spots and ladder element patterns are used for cooling linear hot bodies. Ladder element patterns may also be used on flexible substrates to be folded to form corrugations having cold strips and hot strips on opposing sides to which sheets of suitable material can be attached to form panels, blankets, therapeutic devices or pipe covers for heating or cooling their contents as desired.

Abstract: Thermoelectric device having a number of thermoelectric elements electrically connected in series and thermally connected in parallel. Each element is provided with two element halves, electrically connected in series and thermally connected in parallel, of opposite conductivity types. Each element half has two semiconducting end pieces and an electrically conducting intermediate piece which are electrically connected in series.

Abstract: A thermoelectric semiconductor multicouple array comprises a substrate of semi-insulating material 10, alternate n-type and p-type strips or legs ion implanted into said substrate and connected together electrically in series, and terminal means 11 connected to said series-connected strips or legs. The array may be incorporated in an integrated circuit chip. A method of making such thermoelectric semiconductor multicouple arrays is also disclosed.

Abstract: A thermoelectric semiconductor multicouple array comprises a substrate of semi-insulating material 10, alternate n-type and p-type strips or legs ion implanted into said substrate and connected together electrically in series, and terminal means 11 connected to said series-connected strips or legs. The array may be incorporated in an integrated circuit chip. A method of making such thermoelectric semiconductor multicouple arrays is also disclosed.

Abstract: A thermoelectric device of the kind that comprises an array of thermoelectric rods of two different materials alternatingly arranged between two carrier plates with each carier plate being a plurality of discrete conductive metal junctions to which the thermoelectric rods are pairwise connected. The two carrier plates are made of synthetic polymeric materials and each of the junctions comprises a monolithic metal member directly linked to a carrier plate.

Abstract: A temperature difference detecting element utilizing thermoelectromotive force which is generated by a Seebeck effect when temperature gradients are applied to a semiconductive ceramic material. A substrate has a plurality of thermoelements. Each thermoelement comprises a semiconductive ceramic material and a pair of hot-side and cold-side electrodes which are provided on the semiconductive ceramic material with a prescribed spacing, to form a hot junction and a cold junction respectively. A plurality of such hot-side electrodes are arranged on a first region of the substrate to be adjacent to each other, while a plurality of such cold-side electrodes are arranged on a second region of the substrate to be adjacent to each other. The plurality of thermoelements are sequentially connected in series with each other by electrically connecting, for example, the hot-side electrodes of the thermoelements with the cold-side electrodes of those adjacent thereto.

Abstract: A probe for measuring heat includes an elongate rod fitted within a sheath, and a plurality of annular recesses are formed on the surface of the rod in a spaced-apart relationship to form annular chambers that are resistant to heat flow. A longitudinal bore extends axially into the rod and within the cylinders defined by the annular chambers, and an integrated heater and thermocouple pack is dimensioned to fit within the bore. In construction, the integrated pack includes a plurality of wires disposed in electrical insulation within a sheath and a heater cable. These wires include one common wire and a plurality of thermocuple wires. The common wire is constructed of one type of conductive material while the thermocouple wires are each constructed of two types of materials so that at least one thermocouple junction is formed therein. All of the wires extend the length of the integrated pack and are connected together at their ends.

Abstract: A structure for joining thermoelectric and heat exchange elements in series so that the combination can be operated as a heat pump, at an elevated voltage with high efficiency when transporting high heat flux levels across very small temperature differences.

Abstract: The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta"-alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta"-alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta"-alumina solid electrolyte of the tubular member. A transition piece is positioned about the interior of the member and contacts the transporting means.

Abstract: The present invention provides a thermoelectric converter including a series of thermoelectric cells bonded to a hot surface and to a waste heat conductor. The heat conductor is in turn bonded to cooling pipes which have corrugations to prevent the build up of thermal stresses in one direction. Thermal stress is avoided in a second direction, perpendicular to the first, by having spaces located between the thermoelectric cells. The converter can be folded into a compact configuration and is applicable to satellite power systems.

Abstract: The apparatus of thermoelectric effect for current generation in internal combustion engine vehicles and the like, with recovery of the externally dissipated heat, according to the present invention, comprises a thermoelectric generator provided with several Peltier effect elements undergoing heat transfer with a high-temperature fluid originating from the engine and with a cooling fluid, and possessing electrical conductors connected to their ends across which a thermoelectric e.m.f. is generated, said conductors being connected to an electrical user circuit.

Abstract: A probe for measuring heat includes an elongate rod fitted within a sheath, and a plurality of annular recesses are formed on the surface of the rod in a spaced-apart relationship to form annular chambers that are resistant to heat flow. A longitudinal bore extends axially into the rod and within the cylinders defined by the annular chambers, and an integrated heater and thermocouple pack is dimensioned to fit within the bore. In construction, the integrated pack includes a plurality of wires disposed in electrical insulation within a sheath and a heater cable. These wires include one common wire and a plurality of thermocouple wires. The common wire is constructed of one type of conductive material while the thermocouple wires are each constructed of two types of materials so that at least one thermocouple junction is formed therein. All of the wires extend the length of the integrated pack and are connected together at their ends.

Abstract: Thermal fluxmeter with a plurality of thermocouples comprising a continuous thin layer of a first conductor or semiconductor material such as constantan, covered on at least one of its faces by a succession of areas comprised of very thin deposits of a second conductor or semiconductor material such as copper, having a thermoelectric power different from that of the first material; the characteristic of the invention is that at least one channel traverses from side to side through each deposit area and through the underlying thin layer, said channels being offset in the same direction with respect to the center of the traversed area; said channels may be provided with an inner coating of a deposit of the second material; appropriately, the thin layer is deposited on a substrate of insulating material.

Abstract: A thermoelectric unit is disclosed having superposed PN semiconductor thermoelectric stages (10, 12) thermally and electrically connected together by a planar ceramic coupler (14) therebetween. The PN semiconductor blocks (16, 18) of each stage are connected by metallic bridging elements (20), which bridging elements are soldered to isolated metallized areas (40) on each face surface of the ceramic coupler (14) to thereby form a thermal path between the stages. Each stage further includes power source tabs (22,24; 26,28), the tabs (26,28) of one stage receiving power from the other stage through electrically conductive metallized edge paths (42, 44) on the ceramic coupler (14). This forms an interstage connection for connecting the PN semiconductor blocks of the one stage to the PN semiconductor blocks of the other stage.

Abstract: A lockable, mechanically secure coupling is provided for heat exchanger tubes which are connected together by end plates into superimposed layers (A or B) to form hydraulic connections between the extremities of two tubes (1) using tubular elbows (3). Each tubular elbow (3) has a coupling member (5) connected to the extremities thereof by welding, brazing or glueing to form a coupling flange. The subassembly comprising an elbow with its coupling member (5) is received in a countersunk recess (10) in the external face of the end plate and is mechanically locked by pairs of straight pins (13) which extend into spaced parallel bores (12) or (15), disposed orthogonally to the axis (XX) of the tubes (1), each pin (13) being received in an external semicircular groove (9) of the coupling member (5). The invention provides a tight, mechanically sound joint for the hydraulic connections between tubular heat exchangers used in thermoelectric devices employed as heat pumps or as electrical generators.

Abstract: A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use thermoelectric generators.

Abstract: A method of selecting optimum values for the factors H and .mu. in a thermoelectric heating/cooling device. A system model is formulated by relating the heat transfer characteristics of the heat exchangers on the hot and cold sides of the device to the thermoelectric properties of the TE couples. The model yields a set of governing differential equations that take into account the relative flow directions of the fluids and the position dependence of the temperatures. The equations can be solved and the solutions used in an iterative procedure to select optimum values of H and .mu. that will meet the specified heating or cooling requirements. In a less rigorous method, the average temperatures on the hot and cold sides of the device are used, and these temperatures are mathematically expressed by equations that normally provide results within acceptable margins of error.