Using PC components for temp control

[espenlg]

I have a small temperature-issue here, and I've solved it by using a large table-fan blowing the heat away from the top of the tank..

But then I was thinking, maybe I could automate this by using PC components and computer-fans..

There are plenty of temperature controllers available cheap, but my question is - would the water be affected by the probes?

I'm thinking of probes like this:
http://www.frozencpu.com/tmp-27.html

Thanks!

 

[kgross]

If you are worried about the water being affected by the probe, just seal the probe in some inert epoxy or silicone. It will slow down the temp responce since it will have to change temp of more material, but it will still work.

Kim

 

[espenlg]

I'm a little suprised that noone else has comments about this? Must be the absolutely cheapest temperaturecontrol system available? Not to mention how many cool controllers that's made for computers these days

 

[BeanAnimal]

Buy a RANCO to control the temp. Use the computer to LOG the temp. You really don't want a PC in charge of one of your tanks most critical life support systems do you?

 

[perpetual98]

I just broke down and bought a Ranco to play around with. It's on my 2.5G pico right now, but it'll probably move to one of my 120G tanks at some point. I'm sure if I searched back long enough ago, I could find my thread where BeanAnimal and I would argue back and forth. He was telling me to buy a Ranco and I was trying to build my own temperature controller. About a year later, I have the Ranco and no home-built temperature controller.

Anyway, I looked briefly into the computer temp controllers and just figured that they were tuned to handle higher temps like CPU's and stuff. Maybe they can be set up for lower temperatures.

Bean, I think that you can get some temperature controllers for computers that are just add-on hardware and can be set up to not interface with the OS at all. They have a controller that fits into a 5.25" bay and has some sensors and stuff. Switches 12V fans on and off.

Or maybe I'm way in left field. It's happened before.

Eric

 

[BeanAnimal]

Nah I am sure there are some that just do their thing and only report to the OS via USB or whatever

I have about 15 temp probes that will be connected to my system (dallas 1-wire) but the RANCO will still do the control. It's s little workhorse that I don't have to worry about.

Now the guys with NON PC based controllers may have better luck. I just don't want the finicky nature of a PC to be responsible for my tanks temperature. There is way to much going on inside a windows machine.

 

[perpetual98]

<a href=showthread.php?s=&postid=7893667#post7893667 target=_blank>Originally posted</a> by BeanAnimal
There is way to much going on inside a windows machine.

Great. Now the Linux fanboys are going to chime in.

 

[espenlg]

Yes, I was thinking about the ones that doesn't really use the OS or computer at all. Just supply it with 12V and it works without the computer.. The temperature probes works from 20-80 celcius with 0,1 accuracy.. Or something in that area..

I'm also looking into building the DIY project at OZReef, but it's gonna cost me around $100, so then I might aswell buy something that's already tested and failproof.. How much is one of those Ranco's?

 

[perpetual98]

I have all the OZReef documents printed out, but they seem to me to be lacking in detail and part numbers for us in the US. The Ranco units can be ebay'd for around $50 for a single stage, and about $100 for the dual stage ones that will control fans or chillers.

 

[BeanAnimal]

The part numbers should cross reference easily. All of those parts are just standard off the shelf values. Digikey, Newark, Allied etc will have them.

However even though the project is fairly easy and straightforward, it's a lot to chew for an electronics novice. It could be done, but will be made harder if you don't have some kind of electronics construction and troubleshooting experience.

The RANCO may be your best bet while you work on the OZ project

 

[espenlg]

Yes, I agree partnumbers would be usefull, I spent two hours today searching for similar components on a website we have here called ELFA.. So if anyone wants to try I can share it when I've completed it

But then again - how much temperature variations do you allow for in your tank? Mine varies from 25C in the morning to 27-28C in the evening.. Is that to much variations for the average reef?

 

[BeanAnimal]

Don't rely on catalog numbers...

Just look for component values and component types.

5% 1/4 watt 120K resistor... they are all the same.
22uF Ceramic Disc Capacitor or Electrolytic Capacitor...

I glanced at the partslist and didn't see anything hard to find on it.

 

[adnup]

Heres the best price I found for a <a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7586707654&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1" target="_blank">RANCO</a>