Misplaced Pages

Revision as of 13:42, 23 August 2013

Jean Charles Athanase Peltier (/ˈpɛlti.eɪ/; French: [pɛlˈtje]; February 22, 1785, in Ham – October 27, 1845, in Paris) was a French physicist. He was originally a watch dealer, but at 30 years old took up experiments and observations in the field of physics.

Peltier was the author of numerous papers in different departments of physics, but his name is specially associated with the thermal effects at junctions in a voltaic circuit. He introduced the Peltier effect. Peltier also introduced the concept of electrostatic induction (1840), based on the modification of the distribution of electric charge in a material under the influence of a second object closest to it and it's an electrical charge. This effect has been very important in the recent development of non-polluting cooling mechanisms

Biography

Peltier initially trained as a watchmaker and was up to his 30s working as a watch dealer. Peltier worked with Abraham Louis Breguet in Paris. Later, he worked with various experiments on electrodynamics and noticed that an electronic element when current flows through a temperature difference or temperature difference at a generated current flow. In 1836, he published his work to the 1838 by Emil Lenz were confirmed. Furthermore, Peltier dealt with topics from the atmospheric electricity and meteorology. In 1840, he published a work on the causes and formation of hurricanes.

Peltier's papers, which are numerous, are devoted in great part to atmospheric electricity, waterspouts, cyanometry and polarization of sky-light, the temperature of water in the spheroidal state, and the boiling-point at great elevations. There are also a few devoted to curious points of natural history. But his name will always be associated with the thermal effects at junctions in a voltaic circuit, a discovery of importance quite comparable with those of Seebeck and Cumming.

Peltier discovered the calorific effect of electric current passing through the junction of two different metals. This is now called the Peltier effect (or Peltier–Seebeck effect). By switching the direction of current, either heating or cooling may be achieved. Junctions always come in pairs, as the two different metals are joined at two points. Thus heat will be moved from one junction to the other.

Peltier effect

The Peltier effect is the presence of heating or cooling at an electrified junction of two different conductors (1834). His great experimental discovery was the heating or cooling of the junctions in a heterogeneous circuit of metals according to the direction in which an electric current is made to pass round the circuit. This reversible effect is proportional directly to the strength of the current, not to its square, as is the irreversible generation of heat due to resistance in all parts of the circuit. It is found that, if a current pass from an external source through a circuit of two metals, it cools one junction and heats the other. It cools the junction if it be in the same direction as the thermoelectric current which would be caused by directly heating that junction. In other words, the passage of a current from an external source produces in the junctions of the circuit a distribution of temperature which leads to the weakening of the current by the superposition of a thermo-electric current running in the opposite direction.

When electromotive current is made to flow through a electronic junction between two conductors (A and B), heat is removed at the junction. To make a typical pump, multiple junctions are created between two plates. One side heats and the other side cools. A dissipation device is attached to the hot side to maintain cooling effect on the cold side. Typically, the use of the Peltier effect as a heat pump device involves multiple junctions in series, through which a current is driven. Some of the junctions lose heat due to the Peltier effect, while others gain heat. Thermoelectric pumps exploit this phenomenon, as do thermoelectric cooling Peltier modules found in refrigerators.

The Peltier effect generated at the junction per unit time, ${\displaystyle {\dot {Q}}}$, is equal to

${\displaystyle {\dot {Q}}=\left(\Pi _{\mathrm {A} }-\Pi _{\mathrm {B} }\right)I,}$

where,

${\displaystyle \Pi _{A}}$ (${\displaystyle \Pi _{B}}$) is the Peltier coefficient of conductor A (B), and

${\displaystyle I}$ is the electric current (from A to B).

Note: Total heat generated at the junction is not determined by the Peltier effect alone, being influenced by Joule heating and thermal gradient effects.

The Peltier coefficients represent how much heat is carried per unit charge. With charge current continuous across a junction, the associated heat flow will develop a discontinuity if ${\displaystyle \Pi _{A}}$ and ${\displaystyle \Pi _{B}}$ are different.

The Peltier effect can be considered as the back-action counterpart to the Seebeck effect (analogous to the back-emf in magnetic induction): if a simple thermoelectric circuit is closed then the Seebeck effect will drive a current, which in turn (via the Peltier effect) will always transfer heat from the hot to the cold junction.

The true importance of this "Peltier effect" in the explanation of thermoelectric currents was first clearly pointed out by Joule; and Sir W. Thomson further extended the subject by showing, both theoretically and experimentally, that there is something closely analogous to the Peltier effect when the heterogeneity is due, not to difference of quality of matter, but to difference of temperature in contiguous portions of the same material. Shortly after Peltier's discovery was published, Lenz effected by means of it the freezing of small quantities of water by the cold developed in a bismuth-antimony junction when a voltaic current was passed through the metals in the order named.

Publications

Listed by date

Other

• Notice des faits principaux et des instrumens nouveaux ajoutés à la science de l'Electricité par M. Peltier.
• Mémoires sur l'électricité des vapeurs, sur l'électricité atmosphérique et sur les trombes. Imprimerie de Cosson.
• Météorologie électrique: Première partie

References and notes

General

• The Annual Report Of The Board Of Regents Of The Smithsonian Institution. 1867 Doc. No. 86. 1868. p158+.
• Florian Cajori, A history of physics in its elementary branches. 1922. p269.

Citations

1. Catalogue of the Wheeler gift of books, Volume 2. By American Institute of Electrical Engineers. Library, Latimer Clark, Schuyler Skaats Wheeler, Andrew Carnegie, William Dixon Weaver, Engineering Societies Library, Joseph Plass
2. "Peltier effect". dictionary.reference.com (ed. though transcribed as two syllables, the recording is more natural, with three)
3. A Handy Book of Reference on All Subjects and for All Readers, Volume 6. Edited by Ainsworth Rand Spofford, Charles Annandale. Gebbie publishing Company, limited, 1900. p341 (ed., also Gebbie, 1902 version, p341
4. ^ The New Werner Twentieth Century Edition of the Encyclopaedia Britannica: A Standard Work of Reference in Art, Literature, Science, History, Geography, Commerce, Biography, Discovery and Invention, Volume 18. Werner Company, 1907. p491
5. Contemporarily, known as the thermoelectric effect.
6. or generated
7. This is usually a heatsink and fan assembly.
8. The Peltier effect, where current is forced through a junction of two different metals, also forms the basis of the small 12/24 volt vehicular HVAC systems. It forms the basis of the relatively costly, but stable, junction heated soldering irons. It is used for spot cooling of certain integrated circuits.
9. ^ Yu. A. Skripnik, A. I. Khimicheva. Methods and devices for measuring the Peltier coefficient of an inhomogeneous electric circuit. Measurement Techniques July 1997, Volume 40, Issue 7, pp 673-677
10. The magnetic field B is sometimes called magnetic induction.
11. Mathematical and physical papers, by Sir William Thomson. Collected from different scientific periodicals from May, 1841, to the present time. Kelvin, William Thomson, Baron, 1824-1907., Larmor, Joseph, 1857-, Joule, James Prescott, 1818-1889. vol. viii. p. 90
12. Also contains the papers of: Achille Barbier, Edouard Ernest Blavier, Hippolyte Marié-Davy, comte Th Du Moncel, François Victor Périn, Karl Albert Holmgren, B. Galletti, A. Jounin, Achille Cazin, Emil Kopp, Breton frères
13. Tr. Observations on a new species of floscularia
14. Tr. Notice of the main facts and new instruments added to the science of electricity.
15. Tr. Notice key facts added to the science of Electricity
16. Tr. Observations on multipliers and on thermo-electric batteries
17. Tr. Memory training tables reports that between the strength of an electric current and the deflection of needles multipliciateurs: follow-up research on the causes of disruption of thermocouples and how to ensure in their job measuring average temperatures
18. Tr. Memory on the various species of mist
19. Tr. Meteorology :Observations and experimental research on the causes that contribute to the formation of tornadoes.
20. Tr. General considerations on the ether, followed by instructions on shooting stars
21. Tr. Essay on the coordination of the above causes, produce and accompany electrical phenomena
22. Tr. Letter to the cause of differences between the results of the experiments of MM. Bravais and Peltier on the temperature of boiling water and the results of experiments cabinet.
23. institut. 22 avril 1844. (Comptes-rendus, vol. 18, p. 768.)
24. Tr. Observations in the Alps on the boiling temperature of water.
25. Tr. The cyanométrie and air polarimetry: or user of the additions and changes made to the cyano-polariscope M. Arago, to make cyano-polarimeter in the observation of all points of the sky.
26. Tr. Notice the fluid forces, and lightning
27. Tr. Notice of the main facts and new instruments added to the science of Electricity by Mr. Peltier
28. Tr. Memoirs of electricity vapor on atmospheric electricity and waterspouts
29. Power Meteorology: Part One

Template:Persondata

This article about a French physicist is a stub. You can help Misplaced Pages by expanding it.

• v
• t
• e

• French physicists
• 1785 births
• 1845 deaths
• People from Somme
• French physicist stubs