Your SlideShare is downloading. ×
0
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
The thermo electric effect
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

The thermo electric effect

4,333

Published on

0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
4,333
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
325
Comments
0
Likes
4
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide
  • Change in electrons
  • Charge carrier diffusion if electrons move from hot to cold, then a positive immobile nucleus is left at hot side to conserve charge. So this gives rise to a voltage. Phonon Drag: Similar, P has holes while N has excess by running current the incoming electrons distort nearby electrons thus causing a degradation in mobility and thus a lower temperature.
  • Thermo Couples used to be only two different metals but now you have p and n type Used to be metal not p and n semiconductors2000 degress Celsiusseries
  • P type has a deficiency of charge carriers and n types have an excess
  • Thermo power is measured across the material
  • Transcript

    • 1. THE THERMO-ELECTRIC EFFECT By, Prajwal Keranahalli
    • 2. WHAT IS IT?The thermoelectric effect is the direct conversion of temperature differences to electric voltage or vice-versa.The direction of heat flow can be controlled by changing polarity of the voltage source
    • 3. HISTORYIn the 1820’s Thomas Seebeck (Germany) discovered that if two metals at different temperatures were touching you could create an electric currentJean Peltier discovered that the opposite was also true. By sending a current through two metals you could create differences in temperature
    • 4. WHY DOES THIS EFFECT OCCUR?Charge Carrier Diffusion and Phonon Drag Seebeck Effect Peltier Effect
    • 5. THERMOELECTRIC MODULE
    • 6. THE ZEROTH LAW OFTHERMODYNAMICSPairs of P and N type conductors are both it contact with a copper plate.There will thermo power until the system is at equilibrium. (All three materials are at the same temperature)
    • 7. SEMICONDUCTORS Semiconductors have an electrical conductivity between materials like copper and glassThey possess and interesting property where its conductivity increases with added temperatureP and N type (thermocouples) semiconductors are created by doping.
    • 8. PHYSICS BEHIND IT
    • 9. THERMAL CONDUCTIVITY OFCERAMICS
    • 10. APPLICATIONSThermoelectric generatorCooling ComputersDrink CoolersRecharging DevicesSpace ProbesSolar PowerClothingUseful, Quiet, no Moving PartsIt is less efficient (10%) and more expensive
    • 11. TEST FOR UNDERSTANDINGThe USB Coffee cup warmer is an example of the Seebeck Effect or the Peltier Effect?Before the P and N type Semiconductors what material were used instead as thermal couples for thermoelectric modules?What are the advantages of using thermoelectric generators over, for example heat engines?
    • 12. REFERENCESRockwood, Alan L. (1984). "Relationship of thermoelectricityto electronic entropy". Phys. Rev. A 30 (5): 2843–4. Bibcode1984PhRvA..30.2843R. doi:10.1103/PhysRevA.30.2843G. Jeffrey Snyder and Eric S. Toberer "ComplexThermoelectric Materials" Nature Materials 7, 105-114(2008).CRC Handbook of Thermoelectrics, Introduction, Edited byD.M. Rowe, CRC Press, 1995.G. Jeffrey Snyder, Tristan Ursell. "Thermoelectric efficiencyand compatibility" Physical Review Letters, Vol 91 p. 148301(2003)

    ×