Thermoelectricity 101

by Richmond Laney

Thermoelectricity is the direct conversion of heat into electric energy, or vice versa. The term is generally restricted to the irreversible conversion of electricity into heat described by the English physicist James P. Joule and to three reversible effects named for Seebeck, Peltier, and Thomson, their respective discoverers.
According to Joule’s law, a conductor carrying a current generates heat at a rate proportional to the product of the resistance ® of the conductor and the square of the current (I). The physicist Thomas J. Seebeck discovered in the 1820s that if a closed loop is formed by joining the ends of two strips of dissimilar metals and the two junctions of the metals are at different temperatures, an electromotive force, or voltage, arises that is proportional to the temperature difference between the junctions. A circuit of this type is called a thermocouple; a number of thermocouples connected in series are called a thermopile.

In 1834 the French physicist Jean C. A. Peltier discovered an effect inverse to the Seebeck effect: If a current passes through a thermocouple, the temperature of one junction increases and the temperature of the other decreases, so that heat is transferred from one junction to the other. The rate of heat transfer is proportional to the current and the direction of transfer is reversed if the current is reversed.

The Scottish scientist William Thomson (later Lord Kelvin) discovered in 1854 that if a temperature difference exists between any two points of a current-carrying conductor, heat is either evolved or absorbed depending upon the material. (This heat is not the same as Joule heat, or I2R heat, which is always evolved.) If such a circuit absorbs heat, then heat may be evolved if the direction of the current or of the temperature gradient is reversed.

It can be shown that the Seebeck effect is a result of the combined Peltier and Thomson effects. Magnetic fields have been shown to influence all these effects. Many devices based on thermoelectric effects are used to measure temperature, transfer heat, or generate electricity.


Please view this page which has other images of an intermittent pilot system.
This page is a better explanation of how the mercury flame sensor system works.
If you need to set your heat anticipator you will need a clamp on ammeter.
If your pilot light blows out or is a nusiance to relight add a relight module
Read about repairing an Amana furnace with a combustion blower./
If you also have a heat pump this page will help you repair it.
What is a cracked heat exchanger.
ICE RINK EQUIPMENT FOR SALE

 Read more that I have written on this subject at the freegas page
 and the question page .
To find out more about fan and blower motors click here
To find out what controls the fan in the heat mode or proper settings
To get parts look to Grainger or Johnstone.
To solve a problem use the link to the form below.
 Scott Meenen



About us
About Scott Meenen
Why Choose Us
Oil burner fillout form
Oil heating page
Thermostat facts
heat anticipator question
heat anticipator setting
control wiring colors
electric furnace service
Free Hot Water
Geothermal Heat pump
F.A.Q.
Glossary of Terms
 electric furnace fuses
 Spa and hot tub repair
Aquatherm heater fix
Electric Heat Facts
Free Pool heating
Pool service and repair
Solar Energy
Uses for solar energy
solar energy sitemap
Solar hot water heating
Segal Solar Systems

 To solve a problem use our furnace service fill out form
To solve a heat pump or air conditioning problem use this form
To solve gas burner ignition problems try this form.

Written By:  Richmond Laney for:
G&S MECHANICAL SERVICES.
Specializing in Mechanical, Controls and Electrical Modifications Of
Heating, Air conditioning, Refrigeration, Cold storage,
Ice Production and Food preservation.
Anything having to do with Heat and Energy.
Serving Maryland, DC, and Northern VA.
Contact us by pager: 1-877-467-2914

Page us by e-mail 4103560613.3732505@pagenet.net 240Chrs max.

If I can improve this page please let me know.
Email us at: jsmeenen@toad.net
                 This text written by: Scott Meenen
All files can be seen at the G&S Mechanical Framed home page


ITEMS FOR SALE