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 #2390
Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381
Elegant solution: Modify one controller or build an amplifier for it so it can drive 4 TEC modules.
Ghetto solution: Stuff the 4 thermistors into one thermowell.
I did actually think about shoving all 4 thermistors into one well !! I Did also tag that idea with "ghetto rig". I did some searching yesterday after Ash mentioned using the 2.5k thermistor. I could only find 2.2k in what they call "standard" sizes. When i have the controllers in hand i will surely know more about what i can do with them. One main reason i want to stick with these controllers is that they are cheap! Another is that they switch the output polarity based on the set point to heat or cool. I guess another solution, after some testing, would be two thermowells and two 5k thermistors. If that also turns out to be trouble i may need to make my own instead of using the encased models. (the kind in the stainless 1/4 inch tube)
Here is a picture of the main system this setup will be a companion to, should give you guys an idea of what i am doing with this!
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
2.2 should be fine if you are able to adjust the set-point.
I'd be very surprised if these controllers output anything other than a fixed voltage.
If it works the same as the control circuit illustrated in section 3.1 here:
you may be able to use the 'standard' 10k thermistor, as the voltage drop across each resistor will be the same (assuming there is no 'common earth' (and I can't see why there would be one).
Registered Member #2390
Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381
Thanks again Ash! Good link! Plenty of good information there! If that controller wasn't so expensive (almost $600 without shipping) I would have 4 of those! Very nice setup and the software is an added bonus.
I will have all 4 controllers in hand first week of January according to the tracking. The first thing i am going to do is measure the voltage at the sensor terminals. (There are only two pins, neither of which are marked + or -) I do know that the controller is not grounded. It is powered, and supplies power to the tec through only one input. 12vcd at the two input terminals supplies fan, controller, and tec power. The body is also plastic so mounting it in the enclosure will not ground it.
Maybe the ticket will be to use a small and separate vref supply and the one 10k thermistor. I will know more in January!! Thanks for the help and HAPPY HOLIDAYS!!!!
Registered Member #2390
Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381
Well!!! Got the 4 controllers installed, bought a bunch of thermistors in the way of 2.2k, 5k. Also had the 4 10k units that came with the controllers. Everything is working fine using Steve's method. For some reason, when i do parallel two controllers using the 5k thermistor i get odd readings. Currents and voltages are right where they're supposed to be so i am not too sure whats happening. In theory, the two controllers should show the same actual temp on the display with them rigged up in parallel. With the same hysteresis settings and setpoint the two almost seem to be splitting the difference. For example, if one is showing 70 and the other 68, when they update it will flip to 68 and 70. Not too sure whats going on there but i do know it is inside the controller. No damage to the units occurred and when i pop the 10k back onto each one its right back to normal.
For now everything is working just fine!! I might chase Steves "elegant" solution and get into the guts of one these controllers. Using one to run all 4 tec units has been sounding better and better since Steve planted the seed in my brain! That would actually allow me to use a smaller enclosure as well.
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.
Thermistor Question
