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The ultimate beginner's guide to PC FANS

big twinn

Super Member
Veteran
I have sitting in front of me, this fan:
http://www.sidewindercomputers.com/deaf12suhisp.html

this speed controller:
http://www.sidewindercomputers.com/sirh25wa.html

and this power adapter:
http://www.12vadapters.com/adapter/p.../2-amp-2a.html

ive cut the 3 pronged fan (molex fitting?) exposing the blue, red, and black wires. I also have cut the end off the power adapter (the end that goes into a device, not the wall plug end. i have looked through your guide to PC fans but there are 2 issues i am running into!

first: the exposed wire coming from the 12v power adapter only consists of copper wirie and what appears as a white rubber tube (possibly used to keep the round cord shape?) with just an array of copper wire coming from the adapter, what do i need to attach my red and black wires too? (im under the impression that i dont need to mess with the blue wire?) in order to get her up and running?

second: probably this should be answered 1st as it may change the wiring method asked above, but how do i properly wire the fan speed controller to both the fan and power adapter?

Thanks for all your help! trying to figure this out so i can start using my cab! im very visual, if that helps!
 

BC Chronic

Paging Dr.Greenthumb
Veteran
Hey big twinn!!
If you had kept the wire intact coming from the adapter you could have stuck the positive wire INSIDE the hole at the end, secure it with tape or shrink wrap, then wrap the ground around the outside of the metal plug then secured that, you would be fine...thats what I did..seeing as you cut it,do you mean the blue wire from the adapter cord? if so, then thats the positive and the copper wire is the negative..
pm me if you need further help with that and I'll look for pics I have somewhere...
the fan and speed controller both have 3 wires, 1 is power, 1 is ground and the other is the speed controller wire..you hook the fan to the speed controller using those 3 wires( usually red is power, black is ground and its a variety of colours for the speed control)
then you just hook the power and ground of the speed controller( the other set you see on it) to the power and ground of your adapter..then plug it in!!
 

big twinn

Super Member
Veteran
the blue wire i refered to was 1 of the 3 wires coming from the fan. the power adapter only has an array of copper wire...ah damn it!!..i just got it today and it was like 20bucks...did i ruin it? im a poor college student so i hope its salvage able....how do i now go about the power adapter
 

BC Chronic

Paging Dr.Greenthumb
Veteran
its all good..don't worry..
that blue wire is the speed controller so hook that to the third wire coming from the speed controller...it will be the odd colour since its red for positive and black for ground..

the adapter wire is easy to fix..look at the part you cut off with the plug( the metal part with the hole) you should be able to see what colour wire goes to the inside part( which would be the hole on the outside)that will be your positive wire...then all you do is look closely for the same wire on the other part of the wire you cut..the one coming from the box part of the adapter...it may be very tiny but it will be there probably hidden inside the copper wire...
let us know
there has to be 1 there since everything electrical has a postive and ground..
 

archer66

Member
Im am wondering something. If i get a high speed fan like this one here wich i have in hand http://www.sidewindercomputers.com/de80trblhisp.html and run it on 9V (adapter is switchable) will its characteristics lower to 75% ?
The fan is realy damn noisy, but if by lowering Voltage brings the noise down to with the same percentage as the other characteristics it will be fair.
 

SmilinBob

Member
If you lower the voltage it will lower the dba, as well as the cfm, static pressure etc. But judging by the stats on that fan I see no reason why you would have any problems running it on 9v.
 

archer66

Member
I think i even tested it on 5v adapter and it was spining. But what was bothering me , is how the cfm and other data will be lowered with the lowering of 12 to 9v (100 to 75%)?
Will the all go to 75% of their given number?

if everything goes to 75% this makes it cmf 45.0225 rpm 3750 34.125dBA mm HІO 10.35
and at 100% 60.03 CFM 5000 RPM, 45.5 dBA 13.74 mm HІO

And mine is .62A. What do you think , are my asumpsions right?
 
Last edited:

Strangely

Member
Bonjour old bean! Yep, still building but I've actually begun gluing and screwing stuff! Exciting!! So naturally I've forgotten most of the electrical know-how garnered from peeps such as yourself, so I'm trying to refresh myself for the upcoming electric's portion of the build.

Where you say at the beginniing of the thread that...
Traditional wall wart style with adjustable voltage. As above but less cheap and more better. The adjustable voltage lets you, yup, adjust the voltage, lower than 12v if desired. Most fans can be made almost silent this way but remember they won't be working as effectively. The only real con for me is that the amps are pretty measly on these. I can't even run one of my thermaltakes on this.

If I had a power supply that went to 0.5amps and had one per Thermaltake (one 80mm, one 120mm FYI) would that suffice dya think? Such as...
http://www.maplin.co.uk/Module.aspx?ModuleNo=32746

Glad to have you back around man! ;)
 

mmmcake

Active member
i have a pc fan model df1208bm. it says dc12v 0.20a there is a white,black and red wire. i have a couple plugs laying around would any of these work and if so how do i wire them. i have aclass 2 transformer input 120v 60hz 5w with out put 6vdc 100ma, another input ac120v 60hz 3.5w out put dc5v 140ma and a input 120vac60hz 24w output 12vac 1250ma. can i use any of these?
 

SmilinBob

Member
You can use the one with 1250ma (1.25amps). The other 2 have amp rating that are lower than .20.

Cut the tip off of the adapter. One wire should be solid black and one should be black with a white strip. Attach solid black from adapter to solid black from fan. Attach Black /w white strip to red from the fan. Secure with wire nuts and/or electrical tape, and plug it in.
 

mmmcake

Active member
thanks smilinbob. any ideas about wiring? the adapter wires has one with lettering and the other has a white line. and which do i connect them to? white,red,or black? just saw your edit. thanks again.
 

mmmcake

Active member
no go i think its a bum adapter. fans came out of a working pc. and adapter was in my junk drawer. oh well. thanks again for the help truly appreciated.
 

Strangely

Member
Thanks for the advice SmilinBob. I've got no idea how to wire the two together, so think I'll post up pics once I've got the power adaptors and see who reckons which wire to which!
 
G

Guest 142956

I have only read 20 or so posts on this thread and figured I'd 2 cents the ability to vary your DC fan speeds. I wire a dimmer switch into a short extension cord and plug the DC adapter into it, then adjust the fan speed/noise as i see fit.
 

phrike

Member
Great thread, ScrubNinja ! See you haven't posted in 4 months... I just finished all 40 pages, LOL.

I wanted to point out a potential problem when getting 7 volts out of a power supply from the +5 volt line to the +12 volt line. Sometimes this will not work unless there is a load on the +5v at least equal to the 7 volt load.

The reason is that it causes electricity to flow backwards on the +5v line instead of forwards as it should. I've done the 7 volt trick on some PCs I built, but it works because the motherboard takes more 5 volt current than the fan does at 7 volts.

Another trick I've done is to open up a power supply and adjust voltage to get about 10% more for a specific need I had. Many power supplies have such an adjustment (usually loc-tited) that can change voltage up or down 10% or so. Just be aware that it adjusts ALL PS voltages and that it could cause damage if connected to computer or other equipment with non-standard voltages.


I'm looking to build a few PC case grow boxes with high stealth. I might try to install a small as possible motherboard so it actually works as, and could be sold as (wink), a real computer. Just happens to have a few CFL sockets to show off the computer hardware,... LOL. And yes, even a small mobo would certainly impact growing area, but that's just an option.

I have a background in electronics and S/W development, so I'm also thinking it'd be cool to have fan RPM computer monitored and controlled. Same for lights, temp, humidity etc.
 

Strangely

Member
Greetings wiring massive! As Scrub is on an extended holiday, or just uber-stoned in a field somewhere, it would be very much appreciated if anyone can help with some simple wiring stuff. My tiny cab is all but built and I've been leaving the wiring till last as I'm pretty useless at it. I have 2 ceramic bulb holders to wire up to a plug. I have some nice wire which has three wires in it (L/N/E) do I wire it up as below and just seal off the earth? Thanks in advance everyone! :tiphat:

wiringdiagram01.jpg
 

Kalimaa

Member
I finally decided to try PC fans. I got the first one running quite quickly , but the second not. I mean with one adapter , there should be more than enough power for two fans. I got these "sugarcubes" as folks in the local forums suggested its the way to get several fans wired up on one adapter.
The other fan just doesnt seem to get electricity.
edit: naah fuck it. I dont need another fan.
 
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