Convert 120v to 12v for a Nexus 120mm Real Silent fan

kinetic · Post by **kinetic** » Fri Nov 30, 2007 2:11 am

I need to convert a 120v to 12v for a Nexus 120mm Real Silent Fan. I'm going to radioshack tomorrow to find a converter... but I believe they need three things:

Voltage
Current
Tip Polarity

According to the website, these are the following:

Voltage: 12v
Current: 0.30 Amp Max
Tip Polarity: ??

What is the tip polarity? I think I can just bring the fan in, but I'd like to see some spec as well.

Also what kind of adapter will I need?

Thanks!!

jhhoffma · Post by **jhhoffma** » Fri Nov 30, 2007 8:12 am

You're looking for a standard AC/DC adapter or transformer. They are commonly called "wall warts" because they are the big blocks that take up a huge amount of space on an outlet.

You can buy a variable-voltage one that will allow you to adjust your voltage usually somewhere between 3-12v at standard voltage increments. The tip polarity is usually whether or not the hot lead on the tip is on the inside or outside (male or female head). You won't be using this anyway as you'll have to splice the wires from the adapter to the wires on the fan (the connectors are not compatible)

When you strip the wires one is positive and one is negative. Sometimes the plug wire is color coded so that the ground has a black stripe. If you're not sure where to go from there, then maybe you should research some more wiring instructions. Or I can try to help.

Depending on how many fans you will be connecting you might need a more powerful adapter, but most likely this one should be plenty and it's pretty cheap. That should run at least 3 low speed 120mm fans (though it might get warm).

kinetic · Post by **kinetic** » Fri Nov 30, 2007 10:35 am

the problem is, I don't have a wall plug. I have just regular wires that are hooked up to existing 120v fans that I'd like to replace. I'll need an adapter / transformer that can be hooked up to incoming wires and outgoing wires.

Do they have this?

Flandry · Post by **Flandry** » Fri Nov 30, 2007 2:50 pm

It sounds like what you need is what's called a "muffin fan". It's basically a 120mm 110V AC fan. I think that would be a better option than splicing in an AC/DC converter and 12 V DC fan...

kinetic · Post by **kinetic** » Fri Nov 30, 2007 2:54 pm

Flandry wrote:It sounds like what you need is what's called a "muffin fan". It's basically a 120mm 110V AC fan. I think that would be a better option than splicing in an AC/DC converter and 12 V DC fan...

well, I want to use the quiet NEXUS fans. it used to have 120v fans, but those are incredibly noisy.

Cerb · Post by **Cerb** » Fri Nov 30, 2007 5:49 pm

If you can solder, then doing a dirty job of it, but covered with heatshrink, will be a breeze. If not...er, somewhat of a problem.

jhhoffma · Post by **jhhoffma** » Sun Dec 02, 2007 1:32 pm

Well, if you can think of anything else, you can either crack open the AC/DC converter, remove the plug leads and connect your wires directly to the board inside, or you can cut up an extension cord and use the end (or use one of these.

They are both dirty solutions, but I'm not aware of anything small that will do what you want without a bit of tweaking.

I wouldn't use the 120v fans either, they're almost impossible to get quiet.

kinetic · Post by **kinetic** » Sun Dec 02, 2007 2:20 pm

jhhoffma wrote:Well, if you can think of anything else, you can either crack open the AC/DC converter, remove the plug leads and connect your wires directly to the board inside, or you can cut up an extension cord and use the end (or use one of these.

They are both dirty solutions, but I'm not aware of anything small that will do what you want without a bit of tweaking.

I wouldn't use the 120v fans either, they're almost impossible to get quiet.

thanks for the suggestions. yeah the 120v fans that came with are terrible, which is why I'm swapping them for 12v fans.