DIY stealth cabinet grow...powering PC fan controller?

Hello all,

Building a stealth grow box which I'll do a thread about when it's finished. It's nearly there though.

One main problem as I'm the WORST for technical, electrical and general know-how - what would be the best way to power this PC fan controller from the mains (or PSU or something)? I have a 120mm exhaust PC fan, an 80mm intake PC fan, and 2 USB powered air circulation fans which I was hoping to be able to power from the controller.

Any help would be massively appreciated

I think it would be nice if you could use the controller but it's going to make it much more complicated. Based on the wires you are going to need a motherboard to power the USB ports, and a 12v PSU to run the fans. If you had a PC to dedicate to growing....it might work.

What I would do is forget the controller. To power computer fans or any DC small fan I use old cell phone chargers. Round up your old DC adapters compare the voltages they output to what the fan needs, as long as it's less then it will work fine but at a slower speed. You can use this as your control. Just strip the wires and hook them together, You can soder the connection then tape it up or just tape it well. Test it first to make sure the +/- are correct.

For the usb fans grab a couple of those 120v to usb charger doo-dongle-hicky's and run them from your power bar.

If you are dead set on using the controller, it wouldn't be impossible but I would put the controller in my PC and call it a day.

Cheers,
SilverSerf

Forget the controller. Way too complicated as you need a PSU for the controller and then you need to hack the controller apart to make it work without a motherboard... you might as well just hook them up direct to the PSU.

USB runs on 5V and the other PC fans need 12V. Cheapest way to do this just use a USB mains power supply (like a cheapo phone charger) for the USB fans. Then use a 12V power supply like this:

http://www.ebay.co.uk/itm/141870005624

The 2A PSU would be plenty for a couple of small PC fans. You chop off the connector from the PC fans and screw them into the connector provided (you can connect up 2 fans to the same connector without an issue). You need to identify the positive and negative wires on your fans. There are 4 possible combinations of wire colour coding so I'll direct you at a site with pictures: http://pcbheaven.com/wikipages/How_PC_Fans_Work/

If you really want fan speed control I'd suggest adding a rheostat to the 12V line on the fan to be controlled (25ohm 2w should work fine and would cost about 3 bucks). That would be much easier than trying to integrate your existing fanbus (TBH even thinking about it is starting to give me a headache!).

@loftygoals @silverserf many thanks for your replies. After doing a test run with my CFLs in there I have realised there is no need for the controller -it's getting pretty hot in there so need the fans at full speed, so I'll take your advice on that. I think I was trying to be too clever with something that doesn't need it. We tried powering the fan today with a random low voltage charger and the fan worked, so I think I should (touch wood) be okay for now..

On a side note, my growing space (80x45x70cm) has a total of 275w of CFL in there (8x25w 1x45w, 1x30w). During a test run, with no ventilation or fans running, with the box sealed closed, the temps are reaching 32c at what would be canopy level. Is this normal? I think I'm going to reduce it down to 200w (100w per plant). I'm growing 2 plants, on a 6-week perpetual cycle. Would be nice to pull 1-2oz per plant but would be happy with 20-30g.

Cheers!