Potentiometer needed for 12v PC fan?

[npk]

Hello. I have built a PC grow case but there's still a few things I want to do before I call it complete. I want to be able to adjust the fan speed which is apparently done with a potentiometer. So exactly what size/spec potentiometer do I need? The fan is 12v 0.3A, and my 12v adaptor is 1.25A if that matters.

 

Once I get that, I gather I just wire it in to the red wire on the fan and I'm good to go, yeah? How low will it let me slow it to? And will it allow me to crank it any higher than the normal?

 

Sorta off that topic a bit, but would it be just as simple a wiring job to rig up some sort of thermostat jobby so the fan speeds would be controlled by the temp? Or maybe to keep it simpler, to make the fan come on at a set temp, and cut out at another temp?

 

Should I just go bother the guy at dick smith with these questions? Ta!

[loylty gets u nothing]

a fan speed controller hey

i think they start at around 70$

but then the 1s with built in thermos go for a coupla $$$ MOre

 

but having a small fan as yours

slowing it down isnt gunna do much

infact id say the fam will do nothing,well not much anyways

for extraction centrifugals are best option

slowing fans down will shorten life of fan too imho

anyways all the best

bil

[Tom]

Just get one of those adjustable voltage plug in adaptors from Kmart or Bunnings, the lower the voltage the slower the fan spins, they work very well with PC fans.

 

[npk]

YEAH! Great idea, Tom! I didn't even think of that. Thanks all. I went into Jaycar this morning and asked about potentiometers and they said I'd have to look it up on the net because I'd need all sorts of extra stuff wired in...resistors or something. Over my head. Well, I'll just get a new adapter anyway.

 

I also got a cool fridge thermometer which gives an alarm at set min/max temps, and remembers min/max daily temps, etc. It's awesome.

[Pam]

Oooh oooh... I want one of those thermometers! Kinda like a baby monitor for plants.

[npk]

Yeah I'd get one Pam. It has magnets too so it sticks to my case. I just wish they had one available with humidity too. My dream case would have a thermometer, humidity reading, AND a webcam, all transmitting thru wifi, so I could check it anywhere around the property via laptop, or perhaps over the net if I had to go away. This would also be cool because you could use the webcam to do time-lapse videos of the growth.

[ConvexConepiece]

To control the speed of my 12v 12cm PC fan I use a speed controller that came with one of the computer heatsink/fan combos I bought.... just a low med or high setting.