Peltier effect
The Peltier-Seebeck effect, or thermoelectric effect, is the direct conversion of heat differentials to electric current and vice versa. This effect was first discovered, accidently, by the German physicist Thomas Seebeck in 1821.
The Seebeck effect is the conversion of heat differences directly into electricity. It is the reverse of the Peltier effect, in which a voltage is created in the presence of a temperature difference.
The conductors are attempting to return to the electron equilibrium that existed before the current was applied by absorbing energy at one connector and releasing it at the other. The individual couples can be connected in series to enhance the effect.
Thus, a thermocouple works by measuring the difference in potential caused by the dissimilar wires. Several thermocouples in series is called a thermopile.
Different materials will create different voltage potentials.
This is also the principle at work behind thermal diodes, which are used for creating power from heat differentials.
The Peltier effect occurs when a current is passed through two dissimilar metals or semiconductors (n-type and p-type) that are connected to each other at two junctions (Peltier junctions). The current drives a transfer of heat from one junction to the other: one junction cools off while the other heats up. This effect was observed 13 years after Seebeck's initial discovery in 1834 by Jean Peltier.
The direction of heat transfer is controlled by the polarity of the current, reversing the polarity will change the direction of transfer.
A Peltier cooler/heater or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other.
Peltier coolers are also called TECs (Thermo Electric Converter).
External links
- http://www.uni-konstanz.de/physik/Jaeckle/papers/thermopower/thermopower.html - A paper describing the thermoelectric effect.
- http://www.nanothermel.org/public_main.htm - A website describing the thermoelectric effect, including equations, applications, and further references
- http://www.trnmag.com/Stories/2001/121901/Chips_turn_more_heat_to_power_121901.html - A news article on the increases in thermal diode efficiency
- http://www.sii.co.jp/info/eg/thermic_main.html - A wristwatch powered by thermocouples, using the heat difference between the human body and its surroundings.
Referenced By
1834 in science | Heat Pump | Heating | List of electronics | List of electronics topics | List of physics topics M-Q | Peltier | Segway | Segway HT | Segway Human Transporter | Thermoelectric cooling
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