I need to power 2x120 mm fans

[ric0chet06]

My question is, is that if im only using a 420 watt psu to power 2 120mm fans, would the psu be constantly using 420 watts, or just using enough for the 2 fans? And is there a product out there that plugs into the wall and has the 3pin adapters? thanks

 

[Aluvus]

Originally posted by: ric0chet06
My question is, is that if im only using a 420 watt psu to power 2 120mm fans, would the psu be constantly using 420 watts

No.

or just using enough for the 2 fans?

Yes, plus a little more to cover the power supply's imperfect efficiency.

Also note that the voltage put out by the supply may be significantly out of spec with only that load on it.

And is there a product out there that plugs into the wall and has the 3pin adapters? thanks

None that I'm aware of, though you could make one out of any 12 V DC wall wart. Provided you wanted to run the fans at 100% speed all the time.

 

[ric0chet06]

EXCELLENT! so my power bill won't reflect using 420 watts for using 2 fans. The fans that i want have a knob to increase rpm's. Is there something that i can buy that connects to a 4 pin molex and lets me run like a lamp or a clock? like a molex to wall outlet type thing?

 

[Zepper]

What lamp or clock do you have that runs on DC of 12 Volts or less? I suppose you could hook up some car accessories if you want - as those things are about all that are commonly available that run on 12V DC. You can get PC to cigarette lighter connectors like this - you can find them for much cheaper and with the cigarette lighter jack only. Watch the total current draw with these accessories so as not to overload your PSU. Real Molex/Amp connectors can handle 9A max per pin.

I've also made an adapter that runs my digital camera off 3.3V PC power using something like this as a starting point - it was hard to find the right size power plug for the camera.

.bh.

 

[Modelworks]

Using that large (size of supply, not the wattage) of a supply for just two fans to me would be cumbersome.
You could do a much easier job by just using a 12volt 1A wall adapter.
Alot simpler to manage.

 

[imported_Willie]

Here you go. A wall adapter that converts 110 AC to 12V,2A DC output w/ a single Molex connector on the end. Use a Molex-to-3 pin adapter and you're set. And the beauty part is it's only $10.

http://www.jab-tech.com/12v-DC...Connector-pr-3776.html

 

[Ika]

Originally posted by: Willie
Here you go. A wall adapter that converts 110 AC to 12V,2A DC output w/ a single Molex connector on the end. Use a Molex-to-3 pin adapter and you're set. And the beauty part is it's only $10.

http://www.jab-tech.com/12v-DC...Connector-pr-3776.html

Jab-Tech shipping is pretty killer, turns that low low $10 into a high high $17.