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Topic: Seebeck effect


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In the News (Tue 2 Sep 14)

  
  Seebeck
Seebeck made investigations into photoluminescence (the luminescent emission from certain materials excited by light), the heating and chemical effects of different parts of the solar spectrum, polarization, and the magnetic character of electric currents.
Seebeck is credited with the discovery of the thermoelectrical effect, but he used his discovery to incorrectly conclude that the earth's magnetic field was produced by the temperature differences between the two poles and the equator.
Seebeck also formed a circuit composed of copper and bismuth conductors (wires) in which he held one junction of the metals in one hand, and observed that the needle deflected from the difference in temperature of the metallic junctions caused by the heat of his hand.
chem.ch.huji.ac.il /~eugeniik/history/seebeck.html   (1437 words)

  
 Patent-Invent: Thermoelectricity (Peltier-Seebeck Effect)
The Peltier-Seebeck effect, or thermoelectric effect, is the direct conversion of heat differentials to electric voltage and vice versa.
The Peltier, Seebeck, and Thomson effects are reversible; Joule heating is not, and cannot be, under the laws of thermodynamics.
Such effects can be observed in conductors where the carriers are ions, or in semiconductors where the carriers are holes or electrons.
www.patent-invent.com /electricity/inventions/thermoelectricity.html   (1149 words)

  
  Spartanburg SC | GoUpstate.com | Spartanburg Herald-Journal
Seebeck was born in Reval (today Tallinn, Estonia) to a wealthy Baltic German merchant family.
Seebeck initially believed this was due to magnetism induced by the temperature difference.
The proportionality constant (a) is known as the Seebeck coefficient, and often referred to as the thermoelectric power or thermopower.
www.goupstate.com /apps/pbcs.dll/section?category=NEWS&template=wiki&text=Thomas_Johann_Seebeck   (305 words)

  
 Adventures in CyberSound: Seebeck, Thomas Johann
Seebeck returned to the University of Berlin around 1818 (3) as faculty where he worked independently on the magnetization of iron and steel when electrical currents were passed through conductors.
Seebeck also formed a circuit composed of copper and bismuth conductors (wires) in which he held one junction of the metals in one hand, and observed that the needle deflected from the difference in temperature of the metallic junctions caused by the heat of his hand.
Seebeck devised thermocouples; used thermoelements to measure temperature, built a polariscope (device to measure polarized light); studied heat radiation, and the rotary effect of sugar solutions on plane polarized light.
www.acmi.net.au /AIC/SEEBECK_BIO.html   (1569 words)

  
 Talk:Peltier-Seebeck effect - Biocrawler   (Site not responding. Last check: )
Seebeck was not even alive anymore in 1884.
The Seebeck effect in a bar of metal, showing the flow of hot electrons only.
Is pyroelectricity the same phenomenon as the seebeck effect?
www.biocrawler.com /encyclopedia/Talk:Peltier-Seebeck_effect   (440 words)

  
  Thermoelectrics Basics
Seebeck discovered that if the ends of the circuit consisting of two heterogeneous metals soldered under different temperature conditions were closed, a magnetic needle placed near it would rotate as if there were a magnet applied.
Seebeck gathered much research material that dealt with circuits consisting of various combinations of hard and liquid metals, alloys and compositions of metals and effect of temperature difference on them.
The Peltier effect occurs whenever current passes through the circuit of two dissimilar conductors; depending on the current direction, the junction of the two conductors either absorbs or releases heat.
www.kryotherm.ru /history_spr.html   (800 words)

  
  Idle Reduction - Thermo Fan INC
Seebeck initially believed this was due to magnetism induced by the temperature difference.
The proportionality constant (a) is known as the Seebeck coefficient, and often referred to as the thermoelectric power or thermopower.
The proportionality constant, known as the Thomson coefficient is related by thermodynamics to the Seebeck coefficient.
www.thermofan.com /thermoelectrics.html   (718 words)

  
 [No title]
The Seebeck effect states that when a thermal gradient is applied to a solid, it will be accompanied by an electric field in the opposite direction.
The combined effect of the three principles is that mechanical energy is converted into thermal energy, which in turn is converted into electrical energy as a voltage and current across the sample.
Since, by the very nature of the mechanism, the effect is not restricted to the materials studied, Sood and Ghosh point out that the guiding principle to generate a higher voltage/current should be the choice of materials, such as selenium, tellurium, gallium-arsenide, oxides and electrically conducting polymers, all of which have high Seebeck coefficients.
www.hinduonnet.com /thehindu/thscrip/print.pl?file=20040910004910700.htm&date=fl2118/&prd=fline&   (2399 words)

  
 Seebeck Effect
Seebeck discovered that if two wires made from dissimilar metals are connected at both ends to make two junctions, when one end is heated, a small amount of current would flow through the circuit (see Fig.
If a voltmeter is used to read the millivoltage that the thermocouple produced, a second junction of dissimilar metals is produced at the point where the thermocouple wire is connected to the copper wires of the voltmeter.
One way to get around this problem is to extend the copper wire from the meter to point where a second junction can be produced in such a way that the voltage from this junction can be controlled.
www.data-acquisition.us /industrial_electronics/input_devices_sensors_transducers_transmitters_measurement/Seebeck_Effect.html   (253 words)

  
 Quantum Dot Thermoelectrics
Seebeck discovered that in an open circuit composed of two different conductors with a temperature difference between the ends, a voltage is created.
The Peltier effect states that when an electrical current is passed through a circuit of two different conductors, the junction of the two conductors will either absorb or release heat, depending on the current direction.
The three remaining factors are the Seebeck coefficient a, the thermal conductivity κ, and the resistivity ρ.
www.evidenttech.com /applications/quantum-dot-thermoelectric.php   (1406 words)

  
 Technical Info - Electrical Equations
Seebeck initially believed this was due to magnetism induced by the temperature difference.
The Seebeck voltage does not depend on the distribution of temperature along the metals between the junctions.
The proportionality constant, known as the Thomson coefficient is related by thermodynamics to the Seebeck coefficient.
www.customthermoelectric.com /History.html   (399 words)

  
 The Four Thermoelectric Effects | International Thermoelectric Society
Effect 2 is the Peltier effect - and is correctly identified as the reverse of the Seebeck effect.
Furthermore, in the effect which Seebeck spent the greater part of his career measuring, when the junctions between the dissimilar metals are maintained at different temperatures, a net electromotive force exists in the circuit which causes a current to flow around it.
Such a circuit cannot be constructed with a single conductor, and therefore the definition of Effect 3 may not serve as an adequate definition for the Seebeck effect.
www.its.org /node/3767   (2383 words)

  
 FEEE - Fundamentals of Electrical Engineering and Electronics: Thermocouples
An interesting phenomenon applied in the field of instrumentation is the Seebeck effect, which is the production of a small voltage across the length of a wire due to a difference in temperature along that wire.
This effect is most easily observed and applied with a junction of two dissimilar metals in contact, each metal producing a different Seebeck voltage along its length, which translates to a voltage between the two (unjoined) wire ends.
The Seebeck effect is fairly linear; that is, the voltage produced by a heated junction of two wires is directly proportional to the temperature.
www.vias.org /feee/dcsignal_06.html   (1615 words)

  
 Re: Does the thermoelectric effect exist in superconductors?
The Seebeck effect, named after Thomas Seebeck is the observation that when two dissimilar electrical conductors are connected at two points, and there is a temperature difference between the two points, an electrical current flows between the two points.
Seebeck observed that when copper and bismuth wires were connected at two ends, and one end was heated with respect to the other, a magnitized needle was deflected.
Seebeck reasoned that, because of this thermoelectric effect, the magnetic field of the earth was caused by the temperature between the poles of the earth and the equator.
www.madsci.org /posts/archives/2004-11/1101341951.Ph.r.html   (329 words)

  
 Thermolelectric cooling with Peltier cells
The opposite phenomenon is called the Seebeck effect, discovered in 1821 by the Estonian physicist Thomas Seebeck.
Seebeck effect is the direct conversion of heat energy into electrical energy.
Peltier effect is the heat pumping (moving heat energy from a cold place to a hotter one) by using electrical energy.
www.jcelectronica.com /articles/peltier.htm   (1543 words)

  
 Thermoelectric compensation for voltage control devices - Patent 4097829
In a Seebeck wafer, when heat is applied to the surface adjacent to the varactor diode junction, carriers in the wafer diffuse from the region at the interface with the varactor diode junction to the opposite side of the wafer.
This voltage is, in effect, a feedback voltage controlled by the junction temperature, which acts to oppose thermally induced changes in the varactor diode capacitance characteristic, such as occur in voltage controlled oscillators whenever the frequency is changed.
The Seebeck wafer is isolated from the RF circuitry by bypass capacitors 28 and 29.
www.freepatentsonline.com /4097829.html   (2272 words)

  
 Thermoelectric Technical Reference - Introduction to Thermoelectric Cooling
Seebeck did not actually comprehend the scientific basis for his discovery, however, and falsely assumed that flowing heat produced the same effect as flowing electric current.
In 1834, a French watchmaker and part time physicist, Jean Peltier, while investigating the "Seebeck Effect," found that there was an opposite phenomenon whereby thermal energy could be absorbed at one dissimilar metal junction and discharged at the other junction when an electric current flowed within the closed circuit.
Note that this effect may be reversed whereby a change in the direction of electric current flow will reverse the direction of heat flow.
www.ferrotec.com /technology/thermoelectric/thermalRef01.php   (1161 words)

  
 Introduction to Thermoelectrics
The Seebeck coefficient is defined as the open circuit voltage produced between two points on a conductor, where a uniform temperature difference of 1K exists between those points.
It was later in 1834 that Peltier[2] described thermal effects at the junctions of dissimilar conductors when an electrical current flows between the materials.
This is know as the Thomson effect and is defined as the rate of heat generated or absorbed in a single current carrying conductor subjected to a temperature gradient.
www.thermoelectrics.com /introduction.htm   (1007 words)

  
 Science@Berkeley Lab: Taking the Measure of the Seebeck effect
It was first reported in 1821 by the German-Estonian physicist Thomas Johann Seebeck, who observed that a temperature difference between two ends of a metal bar created an electrical current in between, with the voltage being directly proportional to the temperature difference (the Seebeck coefficient).
Scientists have long recognized that the Seebeck effect could be exploited as an environmentally clean way of producing electricity.
The ability to measure the Seebeck effect in metal/molecule junctions offers promise that extends beyond the field of energy, according to Majumdar and his coauthors.
www.lbl.gov /Science-Articles/Archive/sabl/2007/Feb/Seebeck.html   (1070 words)

  
 Thermoelectric effects
Note too, that the Fermi energy is constant throughout the material (we neglect any possible effects of the temperature on the Fermi energy, as we have it, for example, in doped semiconductors).
As always, electrons go to where the energy is lower; the electrons would tend to move from the hot end to the cold end, thereby transporting energy and thus equilibrating the temperature eventually.
It is conceivable then (also far from clear) that the total effect in terms of temperature differences is proportional to the current I flowing.
www.tf.uni-kiel.de /matwis/amat/elmat_en/kap_2/advanced/t2_3_2.html   (1252 words)

  
 Energy Citations Database (ECD) - - Document #530189
Seebeck effect in the mixed state of the 60-K phase of single-crystal YBa{sub 2}Cu{sub 3}O{sub y}
The resistivity and the Seebeck effect in the mixed state were investigated for the 60-K phase YBa{sub 2}Cu{sub 3}O{sub y} single crystal.
The measured Seebeck coefficient clearly shows an additional contribution at low temperatures, which may be evidence that there are two components (quasiparticles and vortices) carrying entropy in the mixed state.
www.osti.gov /energycitations/product.biblio.jsp?osti_id=530189&query_id=0   (260 words)

  
 Infared Thermocouples
This effect is illustrated in Figure 4-2, with A and B representing the thermocouple wires.
With the compensation means located in the instrument, in effect, the thermoelectric circuit is extended from the thermocouple hot junction to the reference (cold) junction in the instrument.
With this set-up, there are in effect three added thermocouples in the circuit: one in the thermocouple assembly, one in the external extension wire, and in the internal extension wire.
www.tcomega.com /literature/transactions/volume1/infared1.html   (1294 words)

  
 Thermoelectric generators - Patent 6620994
The Seebeck effect is the production of an electrical potential occurring when two different conducting materials are joined to form a closed circuit with junctions at different temperatures.
The third thermoelectric principle, the Thomson effect, is the reversible evolution of heat that occurs when an electric current passes through a homogeneous conductor having a temperature gradient about its length.
According to the Seebeck effect, thermoelectric generation occurs in a circuit containing at least two dissimilar materials having one junction at a first temperature and a second junction at a second different temperature.
www.freepatentsonline.com /6620994.html   (3055 words)

  
 eFunda: Theory of Thermocouples
The basis of thermocouples was established by Thomas Johann Seebeck in 1821 when he discovered that a conductor generates a voltage when subjected to a temperature gradient.
The Seebeck effect describes the voltage or electromotive force (EMF) induced by the temperature difference (gradient) along the wire.
Peltier effect describes the temperature difference generated by EMF and is the reverse of Seebeck effect.
www.efunda.com /designstandards/sensors/thermocouples/thmcple_theory.cfm   (621 words)

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