If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #89
Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145
My single peltier on the pic was on heatsink in ice water (cooled in refrigerator) and I managed to get maybe few degrees under 0 (I didn't measure it precisely).
If I had some smaller peltiers to stack I could get to even lower tempšeratures..
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
There is nothing really wrong with stacking pielters, you just have to make sure that the bottom is much larger than the top one.
For applications like this, it is actually much more efficieny to use a stack. Lets see you get a 130F diferential using 20w of power from a single peilter
Registered Member #223
Joined: Mon Feb 20 2006, 06:42PM
Location: Ottawa, Ontario, Canada
Posts: 125
It would seem to me that each layer of your peltier stack doesn't have a heat spreader to couple the smaller pelteirs to the larger ones. If that's the case then it's about the same as stacking 3 equal sized pelteirs. I can see a little silver thing over the bottom pelt but I can't tell if that’s thermal compound or a very thin heat spreader built into the pelteir. If it is a heat spreader plate it's too thin to do very much anyway.
With no/small load conditions it's ok to stack peltiers to a point; after which you start getting diminishing returns. But you usually want to actually cool an active heat source. This is when stacking pelteirs is bad. I have gotten close to a ~75C difference with one big 320W peltier being water cooled on the hot side to ~25C. The cold side was cold enough to keep a few drops of liquid propane from boiling at 1atm. ~-50C(no load). I had to feed it 30A at 16V though (480 watts!!).
Peltiers are fairly cool devices ( pun not intended) They have no moving parts and can provide many years of constant operation without problems or leaking refrigerant. They are also small for the temperatures they can reach.. I'd like to see someone fit a cascaded phase change system in their pocket.
(hmm seems to be something wrong with Google temperature conversion.. with -64F I get -550C!?!)
Edit: I see what I did wrong.. To get the correct conversion with Google you need to enter '(-64)F to C" not just '-64F to C'
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
I was just relying on the ceramic plate on the tec's as a heat spreader as I didn't have any sutable pieces laying arround. I probabyl could get considerably cooler with them, but the ceramic seems to have a suprisingly high thermal conductivity (I tried to solder on a wire for one that broke and I had to heat the whole thing up to soldering themp to melt the solder)
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
-50C 3 stage pielter cooler
