Thomson Effect
In many materials, the Seebeck coefficient is not constant in temperature, and so a spatial gradient in temperature can result in a gradient in the Seebeck coefficient. If a current is driven through this gradient then a continuous version of the Peltier effect will occur. This Thomson effect was predicted and subsequently observed by Lord Kelvin in 1851. It describes the heating or cooling of a current-carrying conductor with a temperature gradient.
If a current density is passed through a homogeneous conductor, the Thomson effect predicts a heat production rate per unit volume of:
where is the temperature gradient and is the Thomson coefficient. The Thomson coefficient is related to the Seebeck coefficient as (see below). This equation however neglects Joule heating, and ordinary thermal conductivity (see full equations below).
Read more about this topic: Thermoelectricity
Famous quotes containing the words thomson and/or effect:
“High from the summit of a craggy cliff,
Hung o’er the deep, such as amazing frowns
On utmost Kilda’s shore, whose lonely race
Resign the setting sun to Indian worlds,
The royal eagle draws his vigorous young”
—James Thomson (1700–1748)
“Human knowledge and human power meet in one; for where the cause is not known the effect cannot be produced. Nature to be commanded must be obeyed; and that which in contemplation is as the cause is in operation as the rule.”
—Francis Bacon (1560–1626)