12v computer fan help. +rep

TheConstantGardner

Well-Known Member
How can I hook this up so that it can run off an outlet instead of batterys? bongsmilie+rep for help
Go to RadioShack (or any electronics store) and buy a 12v adapter. Cut the leads and attach to your fan.

Look around your house. You've probably got a 12volt adapter from some old gadget. Use it. Check the amp rating on the fan and make sure the 12v adapter can supply at least that much.
 

BigBudBalls

Well-Known Member
The cell phone charger myth HAS to stop. Most phones of the last 5+ years work on 3.3V. You would never charge one with 12V. (but the wallwart idea is fine.)

While you are at RS, just look at 120VAC fans, they have them. Saves the down conversion and loss of energy in that conversion.
 

tom__420

Well-Known Member
The cell phone charger myth HAS to stop. Most phones of the last 5+ years work on 3.3V. You would never charge one with 12V. (but the wallwart idea is fine.)

While you are at RS, just look at 120VAC fans, they have them. Saves the down conversion and loss of energy in that conversion.
I don't think I have even seen a cell charger with that low of voltage. Most of the ones I have seen are between 5-8 volt output
 

beelzbub

Member
When I build my box, I was trying to figure out the same issue. Instead of going through all that work, I bought this power supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817152019

and these fans
http://www.newegg.com/Product/Product.aspx?Item=N82E16835185092

The power supply only cost $15, and you can essentially daisy chain as many fans together as you want as long as they pull less than 380 watts. I found this solution much easier than wiring individual plug in fans. The modifications you need to make to the power supply are much easier than if you bought a 12v adapter. Here is a link for instructions: http://www.gideontech.com/content/articles/196/1

Basically, when you look at the plug that goes into the mobo you'll see 20-24 pins with different colored wires. The green wire is the "ON" wire, and every black wire is a Ground wire. All you have to do is (UNPLUGGED PLEASE!) get a paper clip and bend/cut it so that one ends is in the green plug, and the other end is in any black plug. The circuit is now complete and the power supply will automatically turn on once you flip the switch, no motherboard needed.

On a side note, if you are growing stealth like me (I grow in an apartment) noise is a big factor. Those fans above are hands down the QUIETEST fans I've ever seen. They move great air, and you literally cannot tell they are on once you turn them on.
 

Mr ADHD

Well-Known Member
Oh and FYI folks most cell batteries are:
[FONT=Verdana, Arial, Tahoma]Lithium Polymer (Li-Poly)
Lithium Ion (Li-Ion)
Nickel Metal Hydride (NiMH)
Nickel Cadmium (NiCad)
[/FONT]
99% of theese are 3.6 volts w/ a few odd ones just over 4 volts. Also the amperage from a modern cell phone charger probibly isnt even enough to turn a 12v motor...
 

TheConstantGardner

Well-Known Member
Do you have the computer the fan came from? If so use the Psu from the computer. Sorted!
Why on earth would you want to burn 400-500 watts 24/7 to power a 20cfm computer fan? Secondly, do you know how to pinout a non-switching powersupply to make it work without a mainboard attached?
 

Geozander

Well-Known Member
Why on earth would you want to burn 400-500 watts 24/7 to power a 20cfm computer fan? Secondly, do you know how to pinout a non-switching powersupply to make it work without a mainboard attached?
was just a suggestion. And yes i do know, its my job at the end of the day. Why not jump on the backs of the people suggesting mobile phone chargers running at 4-500 milliamps. I know what i am talking about, have a degree in microprocessor electronics. Do you? You wanna try and get tech with me? Aint what im here for.
 
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