CPU Fan to Wall

[Kbalz]

Hello, I am very interested in powering 3 computer case fans by my
home wall plug. I'm very electrically challenged, but have a few
buddies who have tools I can use.

Here is an example fan

http://www.newegg.com/Product/Product.aspx?Item=N82E16811999479

The fan seems to have a simple power IN and a ground attached. I would
like to be able to switch the amount of volts that go to the fan. It
runs at 12 Volts, but I would like to switch between 9, 10, and 12
volts (to change fan speeds essentially). I've been reading a Wall
Wort can do something like this, but I haven't come accross a full
explaination of how to get everything working together.

Also, say I wanted to have of these fans running through this switch/
wall wort.. do I need 12 * 3 Volts, or can they be daisey chained..?

 

[PCPaul]

On Tue, 19 Aug 2008 12:10:57 -0700, Kbalz wrote:

Hello, I am very interested in powering 3 computer case fans by my home
wall plug. I'm very electrically challenged, but have a few buddies who
have tools I can use.

OK...

The fan seems to have a simple power IN and a ground attached. I would
like to be able to switch the amount of volts that go to the fan. It
runs at 12 Volts, but I would like to switch between 9, 10, and 12 volts
(to change fan speeds essentially).

You'll probably find that won't change the speed all that much. Many
people running fans slower to make them quieter run 12V fans at 5V.

I've been reading a Wall Wort can do
something like this, but I haven't come accross a full explaination of
how to get everything working together.

You can get wall warts which have adjustable output voltages - usually
there's a small slide switch on them somewhere to select what it runs at.

Also, say I wanted to have of these fans running through this switch/
wall wort.. do I need 12 * 3 Volts, or can they be daisey chained..?

You need to connect them in parallel - i.e. all the ground wires
connected together and all the +V wires connected together. That way they
all get the same input voltage *but* the overall current taken from the
wall wart will be three times what one fan is rated at, so make sure it's
big enough.

Also, with your level of (almost no) electronics experience, wiring up
the fans with 12V or so won't be a safety issue, but please don't try
doing anything with mains until you know a lot more about it!...

 

[Kbalz]

On Aug 19, 4:36 pm, PCPaul <u...@bitrot.co.uk> wrote:

You need to connect them in parallel - i.e. all the ground wires
connected together and all the +V wires connected together. That way they
all get the same input voltage *but* the overall current taken from the
wall wart will be three times what one fan is rated at, so make sure it's
big enough.

Thanks for your response, can you explain this a bit more? If one fan
needs 12 volts, and 400 mA and 4.8 W, and I would like to run three of
them at max speed.. I would need to solder all three ground wires
together and all three +V together and into the wort.. so does the
wort have to be 12 volts * 3, or 400mA * 3, or 4.8 W * 3, or all?
Which part of the wort must be 'big enough'? Thanks.

 

[Jasen Betts]

On 2008-08-21, Kbalz <Kurtas.Balczak@gmail.com> wrote:

On Aug 19, 4:36 pm, PCPaul <u...@bitrot.co.uk> wrote:
You need to connect them in parallel - i.e. all the ground wires
connected together and all the +V wires connected together. That way they
all get the same input voltage *but* the overall current taken from the
wall wart will be three times what one fan is rated at, so make sure it's
big enough.

Thanks for your response, can you explain this a bit more? If one fan
needs 12 volts, and 400 mA and 4.8 W, and I would like to run three of
them at max speed.. I would need to solder all three ground wires
together and all three +V together and into the wort.. so does the
wort have to be 12 volts * 3, or 400mA * 3, or 4.8 W * 3, or all?
Which part of the wort must be 'big enough'? Thanks.

12V 400mA*3 4.8W*3

12V
1.2A (or more)
14.6W (or more)

--

Bye.
Jasen

 

[John Fields]

On Thu, 21 Aug 2008 10:40:49 -0700 (PDT), Kbalz
<Kurtas.Balczak@gmail.com> wrote:

On Aug 19, 4:36 pm, PCPaul <u...@bitrot.co.uk> wrote:
You need to connect them in parallel - i.e. all the ground wires
connected together and all the +V wires connected together. That way they
all get the same input voltage *but* the overall current taken from the
wall wart will be three times what one fan is rated at, so make sure it's
big enough.

Thanks for your response, can you explain this a bit more? If one fan
needs 12 volts, and 400 mA and 4.8 W, and I would like to run three of
them at max speed.. I would need to solder all three ground wires
together and all three +V together and into the wort.. so does the
wort have to be 12 volts * 3, or 400mA * 3, or 4.8 W * 3, or all?
Which part of the wort must be 'big enough'? Thanks.

---
First of all, it's not 'wort', it's 'wall wart'.

Second, if each of the fans is rated to draw 400mA at 12V, then when
they're connected in parallel they'll draw as many times more current
as there are fans connected together.

So, if you have three fans and you want to run them at full speed,
your supply must be capable of supplying 12V at 1.2 amperes.

JF

 

[Nicholas Sherlock]

Kbalz wrote:

Hello, I am very interested in powering 3 computer case fans by my
home wall plug.

You've already got a power supply in there providing a range of DC
voltages, why not use it?

Cheers,
Nicholas Sherlock
-----------------
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Access your favorite newsgroups from home or on the road
-----------------

 

[Kbalz]

On Aug 23, 11:22 pm, Nicholas Sherlock <n.sherl...@gmail.com> wrote:

Kbalz wrote:
Hello, I am very interested in powering 3 computer case fans by my
home wall plug.

You've already got a power supply in there providing a range of DC
voltages, why not use it?

Cheers,
Nicholas Sherlock
-----------------www.Newsgroup-Binaries.com- *Completion*Retention*Speed*
Access your favorite newsgroups from home or on the road
-----------------

I'm building a sort of laptop station that will be mounted with fans,
blowing at the laptop.

Sorry for the incorrect spelling.

 

[Kbalz]

On Aug 22, 5:36 am, Jasen Betts <ja...@xnet.co.nz> wrote:

On 2008-08-21, Kbalz <Kurtas.Balc...@gmail.com> wrote:

On Aug 19, 4:36 pm, PCPaul <u...@bitrot.co.uk> wrote:
You need to connect them in parallel - i.e. all the ground wires
connected together and all the +V wires connected together. That way they
all get the same input voltage *but* the overall current taken from the
wall wart will be three times what one fan is rated at, so make sure it's
big enough.

Thanks for your response, can you explain this a bit more? If one fan
needs 12 volts, and 400 mA and 4.8 W, and I would like to run three of
them at max speed.. I would need to solder all three ground wires
together and all three +V together and into the wort.. so does the
wort have to be 12 volts * 3, or 400mA * 3, or 4.8 W * 3, or all?
Which part of the wort must be 'big enough'? Thanks.

  12V 400mA*3 4.8W*3

    12V
    1.2A  (or more)
    14.6W (or more)

--

Bye.
   Jasen

Thanks for the numbers. I've found a wort that is big enough. Now what
do I do to id to hook the three fans to the wort..? I was thinking cut
the end off of the wort, and solder the Red cord of the fans to the
wort.. but what about the grounds..?

 

[Jasen Betts]

On 2008-08-25, Kbalz <Kurtas.Balczak@gmail.com> wrote:

Thanks for the numbers. I've found a wort that is big enough. Now what
do I do to id to hook the three fans to the wort..? I was thinking cut
the end off of the wort, and solder the Red cord of the fans to the
wort.. but what about the grounds..?

do the the same but to the other terminal.

all the red wires from the fans go together and connect to the
positive output wire of tht 12V supply

all the black wires from the fans go together and connect to the
negative output wire of the supply.

if you get the wires backwards it won't work and may damage the fans.

Bye.
Jasen