Peltier modules are pretty neat. You can get more info from a company
called MELCOR. They sell all kinds of Peltier devices, from individual
chips to whole assemblies. http://www.melcor.com/teccover.htm also has
some links to "handbooks" and product information. I'm not sure I can
explain the phenomenom that you observed, but you might try emailing MELCOR
and asking them. If you do get something back, please paste it back to this
thread.

I bought some modules from them a long time ago. At the time, a 1" unit
cost around $25, and I was thinking of using them in a cacaded arrangement
to replace the freon-driven system on my Norcold fridge. Then I learned how
"efficient" they were. Oh well. I do use one of the larger cooler type
units on many occcasions I have filled it with pop and beer and left it
plugged in on my boat all week. When I go out the next weekend, I'm stocked
up with a cooler full of COLD drinks! I have since fixed the Norcold, so
now I just use the peltier cooler for "additional capacity" for parties.


"Glenn Ashmore" wrote in message
...
Can someonr explain the idiosincracies I have observed in a peltier
module?

In scrounging parts for the watermaker I cam across an interesting
surplus assembly. I was really after the 1 gpm flowmeter and stainless
needle valve but it came with a really strange device. One of those
things you just sense is to good to throw away. This thing is a pair of
hollow black anodized aluminum blocks about 4.25"x1.75"x1" with pipe
fittings on each end. They are bolted together with what appears to be
a couple of 1.5" square Peltier modules separating them.

Being a curious sort, I did the natural thing and took it apart to play
with the Peltier modules. First I put them on the VOM to check
resistance. They seems to float around between 19 and 22 ohms. Then I
wired it to a DC power supply and slowly cranked up the voltage. While
one side slowly got warm and the other cooler I could not get it higher
than 3 volts and the current never got above .25 amps. Changing
polarity did not make any difference.

This does not seem to fit any of my perception of the rules of
electricity. What is happening?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
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