DIY - Wiring a PC Fan to DC outlet

Cannabean

Active member

• Sep 12, 2008

• #1

I've seen a whole bunch of questions about how to wire a pc fan to a standard home outlet so I took pics as I made one for a new cab I'm building. I hope this helps some of you.



Fan:
scythe 800rpm 40 cfm 10.7 dba. 100mA
adapter:
pc modem power cable 500mA


Cut the ends off both wires:


Split apart the wires so they are easy to work with and tie/electrical tape the yellow ground wire back.


Carefully strip the sleves off both sets of wire.


Check to see which direction the fan is intended to work.


You can tap the wires together to check if you have POS-POS and NEG-NEG correctly wired. Electrical tape or cap the exposed ends.


Done and ready to be installed in the new mum cab! Enjoy.

 

Mr Celsius

I am patient with stupidity but not with those who

Veteran

• Sep 12, 2008

• #2

Very nice, only thing I didn't see was a mention of voltage. Maybe I missed it. Or am I dumb and not realize that all these PC fans are 12v...

 

FreezerBoy

Was blind but now IC Puckbunny in Training

Veteran

• Sep 12, 2008

• #3

Nice tutorial.

Is there some advantage to DC over AC? Personally I can't stand power bricks. Especially when they're so easily avoided. Or is this "hobby crossover" where people have stuff lying around from their computers, aquariums etc?

 

JWP

Active member

• Sep 12, 2008

• #4

Yeah nice pic tutorial.

Now what if you wanted 2 or 3 fans? I guess you could daisy chain them but what if you wanted them to all have full power?

 

Cannabean

Active member

• Sep 12, 2008

• #5

Mr. Celsius: I didn't list the voltage but its visable in the picture, both adapter and fan are 12v. PC fans are usually 12v.

Freezerboy: Personally, I have a lot of networking parts lying around so it was easy for me to get a power adapter, but doing it this way is inexpensive too. $10 charger at radioshack can power multiple fans and is perfect for a small veg/clone/mother cab.

JWP: If you wanted to power multiple fans with a single adapter just make sure you stay within the adapters amp rating.

The adapter I used is rated for 500mA. The pc fans I use draw 100mA. I am using this charger to power 3 of these fans in parallel. This setup draws 300mA, well under 500mA the charger is capable of.

When wiring multiple fans make sure to wire in parallel:

 

FreezerBoy

Was blind but now IC Puckbunny in Training

Veteran

• Sep 12, 2008

• #6

I'd think AC fans in series would work. More important is that multi fans work best stacked rather than side by side. Just be sure the fans are matched (same model)

 

pHaroaH

Member

• Sep 13, 2008

• #7

I like using a multiple DC voltage adapter. It allows me to adjust the voltage to slow down or speed up the fan. I monitor the heat and RH to find the slowest speed possible. The slower the fan the quieter it is.

 

FreezerBoy

Was blind but now IC Puckbunny in Training

Veteran

• Sep 13, 2008

• #8

Cannabean said:

When wiring multiple fans make sure to wire in parallel:

Click to expand...

Because (for non electrical types like me) wiring in Series means if one fan shorts, they all short. In Parallel if one fan stops then that's it, one fan stopped. Everything else keeps going.

 

Cannabean

Active member

• Sep 14, 2008

• #9

and also

Wiring two fans (ex. 12v and 500mA) to a 12v adapter would halve the voltage. Each fan would recieve 6v but together they would still only draw 500mA. The fans will slow down.

Wiring in parallel the two fans will both recieve 12v and together draw 1000mA, the fans run at full speed.

 

T

TLR

New member

• Oct 25, 2009

• #10

So I've asked some friends and searched this forums trying to figure out how to wire my fans to some old adapters I have lying around.

Based on what I know, there are 6 possible combinations for having a computer fan with a red, black, and yellow wire; as well as an adapter with a positive (non-marked) and negative (white marked) wire.

The combinations are as follows:
1. negative red + positive black
2. negative red/yellow + positive black
3. negative red + positive black/yellow
4. negative black + positive red
5. negative black/yellow + positive red
6. negative black + positive red/yellow

I've done this numerous times and each time with a 12v adapter and a 9v (the fans require 12v but I've heard that having less v just means it will run slower) and each time it hasn't worked at a all.

Can anyone help me? Are there any alternatives?

 

RicoT

Active member

• Oct 25, 2009

• #11

TLR said:

So I've asked some friends and searched this forums trying to figure out how to wire my fans to some old adapters I have lying around.

Based on what I know, there are 6 possible combinations for having a computer fan with a red, black, and yellow wire; as well as an adapter with a positive (non-marked) and negative (white marked) wire.

The combinations are as follows:
1. negative red + positive black
2. negative red/yellow + positive black
3. negative red + positive black/yellow
4. negative black + positive red
5. negative black/yellow + positive red
6. negative black + positive red/yellow

I've done this numerous times and each time with a 12v adapter and a 9v (the fans require 12v but I've heard that having less v just means it will run slower) and each time it hasn't worked at a all.

Can anyone help me? Are there any alternatives?

Click to expand...

The positive goes with the positive and the negative goes with the negative if that's what you're asking.

 

T

TLR

New member

• Oct 25, 2009

• #12

RicoT said:

The positive goes with the positive and the negative goes with the negative if that's what you're asking.

Click to expand...

I already know that, that's why I posted the combinations. I just don't get why it wouldn't be working at all with any of my adapters - all of which have no reason to be fried.