Temperature Regulation Devices

Hello everyone!

Basically wanting to learn more about using devices to regulate temperature by hooking them up to DC fans. I've observed a slight problem: Most devices like thermostats and such are AC powered. I understand that it can be changed from one to another but I'm not exactly clear on what's needed.

I'm looking for something cheap, simple, and connected to a small digital thermometer. Seriously nothing fancy at all, I don't need one thousand buttons, programs, modes or gismo's. Just tell me the temperature, turn my fans off at one temp, turn them one at another, and I'm happy.
I did do some research and found some plans but they were all too technical, written in electrician "code". I'm a very tactual learner and kind of get the jist from the charts but don't have the patience to use any sort of legend to read the zig-zagged lines, K's, V's, circles, dots, broken lines, etc... Morris Code was simpler
(Bit OT Sorry)
Anyway I did find SOME SEEMINGLY Useful words... Like "thermistor", "Comparator LM339", and "MOSFET IRF 510"...

Any help is appreciated.

There are a bunch out there. If you are hung up on using dc equipment, get a regular house thermostat ( mercury bulb ) and go for it. They are "dry" and will take either ac or dc voltage.

There are line voltage stats ( johnson supply, grainger) that have a dial, set the temp and forget it ( works on either voltage )

I have to ask, if you are going with dc equipment, what are you using for a power supply?

Peace

Asmallvoice

Actually if running DC through a HVAC stat make sure it is rated for milivolt operation so it doesnt require 24 AC to function! Then it is a set of dry contacts! Here is what I built for all lighting, heating, and cooling . This is using a board from a furnace to switch from heat and cool thru the fan terminals on it. Works really well and can program different temps and times if needed. Total cost to build was $160.00 stat included and board was free from dead furnace!

ASMALLVOICE said:

There are a bunch out there. If you are hung up on using dc equipment, get a regular house thermostat ( mercury bulb ) and go for it. They are "dry" and will take either ac or dc voltage.

There are line voltage stats ( johnson supply, grainger) that have a dial, set the temp and forget it ( works on either voltage )

I have to ask, if you are going with dc equipment, what are you using for a power supply?

Peace

Asmallvoice

Click to expand...

Ya I'm kind of hung up on using DC fans. It's for a growbox. They are pc fans and DC is less dangerous to play with
When you say they are dry, you're talking about your average house thermostat?
The power supply I'm using is a 12V adapter. How much power does a friggen thermostat need? lol

160$ is way too much. I only want my fans to turn off when it gets too cold and come back on when the heat rises. Kinda like how floor board heaters work.
My attention span doesn't allow me to do it by hand with a switch either.
I'm surprised that THIS has been the most complicated thing I've had to deal with so far lol.

there is infinity of those on e-bay for computers. computer fan controllers...

SnakeByte said:

Ya I'm kind of hung up on using DC fans. It's for a growbox. They are pc fans and DC is less dangerous to play with
When you say they are dry, you're talking about your average house thermostat?
The power supply I'm using is a 12V adapter. How much power does a friggen thermostat need? lol

160$ is way too much. I only want my fans to turn off when it gets too cold and come back on when the heat rises. Kinda like how floor board heaters work.
My attention span doesn't allow me to do it by hand with a switch either.
I'm surprised that THIS has been the most complicated thing I've had to deal with so far lol.

Click to expand...

A regular mercury bulb t-stat needs no power, it is a electro-mechanical device. just makes and breaks a circuit, nothing more, the only load is what you put on the other side of the switch..lol It should handle the load of fewpc fans with no issues.

Yes. the term "dry" means the contacts are non-powered untill you put power to them, whatever it may be, ac, dc doesn't matter.

Peace

Asmallvoice

Awesome. Thanks everyone. I tend to over-complicate things a lot. lol But a thermal pc fan controller is probably what I'm looking for.
I'll have to get some fan pins... I spliced all of mine and didn't keep them.
Thanks again!

Does anyone know about these? : DC 12V Digital Temperature Controller Thermostat C

Can I ask why you are running all this DC gear?

Mini fridge growbox with computer fans for circulation, exhaust and intake. Thread
I've worked with the processing most my life but this is my first personal setup.
I'd like my intake and exhausts (3 Fans) to shut off when temps go below 25ºC/77ºF and then turn on when going above.
PC fan controllers seem to turn on at 30ºC which is already too hot and shut of at 27ºC which isn't cold enough.

SnakeByte said:

Does anyone know about these? : DC 12V Digital Temperature Controller Thermostat C

Click to expand...

I got one of those on ebay for $15 from a Hong Kong seller. I got a 120v model. Took a cheap $3 extension cord and chopped it in half. Plug --> AC In. The "outlet" half of the chopped extension cord has the neutral side always connected. The live side is connected to the controller's relay poles. The thing is programmable so that "on" is either "needs cool" or "needs hot". It came with a surprisingly good manual.
You could do this and then plug a DC wall-wart into the relay controlled extension cord- then you could control whatever you want. If you decide to go with an AC fan, like most would probably suggest, just plug it into the relay controlled extension cord. The temp sense probe is on a wire that is maybe 3 or 4 feet long, I suppose you could extend it somewhat but I would consult the manual.

Was thinking, I could hook them up to my lights if I plug an extension into the light timer so I can also plug my DC into it (which powers the fans) as well....
That way, they are only running when the lights are on! DERP!!! Thanks for your help everyone!

That's cool- the temp controllers are more handy for when lights are on continually. They can regulate within a configurable temperature window. Not bad for 15 bucks Good luck with your project

Right, but I use the 18/6 schedule.
This idea was so close, that if it was a snake, it would have bitten me.
Can't believe I didn't see it sooner...