Re: Standind wave in a magnet

HERNING@uwplatt.edu
Thu, 16 Apr 1998 23:36:06 -0500 (CDT)

<snip>
> As to the Peltiers, I still have the big one you gave me and a couple of
> the smaller ones....it sure is an easy enough experiment to carry out
> and it is a mystery to me also as to how they work..I remember reading
> something about electron donors being involved....

Here is some info on how peltier junctions work, taken from Mark's Standard
Handbook for Mech Engineers:

Peltier Junctions work by the Peltier effect (hence their name) which
involves heating or cooling of the junction of two thermoelectric
materials by passing a current through the junction Semiconductor
thermoelectric materials have greatly increased the effectiveness of
thermojunction for cooling

The Peltier effect is also the inverse of the Seebeck effect in which a
current is produced in a closed circuit of two disimilar metals if the
juction is maintained at different temperatures, as in thermocouples for
measuring temperature.

and it goes on to say how semiconductors have increased the efficency
(which is still very low)

So I guess that it is still a rather fascinating gizmo to work with.
Its too bad they require (a peltier junction) such a huge amount of
current to operate. Just imagine an air conditioner made out of these
for your auto or home, no moving parts, no circulating fluid to leak
harming the ozone layer ect.... Any other comments?

Garrett Herning
herning@uwplatt.edu
http://vms.www.uwplatt.edu/~herning/