fans, computer power supplies..

Answers

"our 3 pronged plugs, why would i be using us plugs?"

The reason I say that is because most computer power supplies only come with 3 pinned plugs (2 Rectangle, 1 Circle - Picture 1).... Unless your place was wired for those type of plugs you will need an adapter to plug it in.



"does that mean i can change the speed of the 12v fan. ?"

No, the voltage switch on the back of the power supply changes the input voltage for the supply itself... So you must match up the voltage coming from your wall to what the power supply needs.... Lets say if you had 220V coming from your wall... If your Power Supply was plugged in and set to 110v, then you would fry the poor thing.

That is why I always reccomend if you dont know how much voltage is coming from your outlets, to set it to 220V first, that way it will either not turn on (Lack of power), or it will be dead on the money.....

If it dosent kick on at 220V then its safe to say there isnt 220V going to the supply so you can kick it down to 110V.

The output going to your fans is going to be a steady 12V from the outputs of the power supply.... CPU fans are rated at 12v so that is the fastest they will go. If you want to slow them down you can do that... But you cannot increase the speed of these fans without more power.... (More power = Shorter Life)


Hope this helps clarify a little...

XS

yeah its all sorted thanx. got the powersupply. a little bigger then expected. not sure where its gonna sit. lol. nah everything is from this country so its all compatible. thanx again, do u do this for a job or is this just a fanatical interest of yours?

Little bit of both...hehehe

My full job title is:

Systems Administrator / Asst. Network Administrator / Webmaster.......


I deal with machines on a daily basis... About 2000 to be exact....LOL

Good to hear you got things straight, youll really like the power supply, you can add soooooooo many fans to it its not even funny....

XS

i know the thread is a little old but hey, valuable info is always worth sharing...

xalted covered hotwiring ATX power supplies but if you're anything like me electricity makes you nervous and a little conformation really helps.

so here it is, diagrams, pictures and all

There are 20 pins on a standard ATX connector. You must first locate pin 14. This pin is very easy to spot since it's the only one with a green wire. All you have to do to make the power supply start is to ground this pin. All pins with black wire coming out of them are grounds. I used a twisted paper clip to make contact between the 2 pins (the green one and any of the black ones). Once your pin 14 is grounded, the power supply should turn on whenever it's switch is on. To know if it works listen to the power supply fan, it will spin whenever the power supply is on.



This is the most basic way to use a second power supply, but it's not very practical if you want to mount it inside your case. You will have to stretch your harm to the back of your case whenever you turn on your system. So the next step would be to relocate the power supply switch to the front of the case. For this, you will need a normal ON/OFF switch and some wires. Simply install the switch between your pin 14 (green) and your ground like this:



here's a link to the page i got this link from with some other options for hotwiring an atx power supply, this is the simplest one and imho the best for our application

Overclocker's Forums

So lemme get this straight, once you do the paperclip thing and the powersupply runs, is that whole process so you can use the fan on the back of the P/S? Or can you use the wires from the front of the P/S to power another or several fans (sorry if this question is stupid)

Schmoke

correct on both accounts, my plan, and many others as well, is to mount all my ballasts in an empty computer case and use the power supply to run all the fans i'll need, just gonna get

once the jumper is in place the power is controlled soley by the switch on the back of the power supply

sales.goldmine-elec.com [Mod note: No direct links to commercial sites please.] has really cheap fans that are perfect for this application

Ok cool. Yeh for mine its 4+ foot high, 2.5 deep and 4 long. What i was trying 2 figure out is if i could have the P/S of a computer on the outside (or inside) Running 2 computer fans as the intake of the grow room. I now know how to get the P/S running without a mainboard, but what i really wanna know is if i can use any of the coloured wires comming out the front of the P/S to directly run fans? Im quite set on using comp fans because i can get P/S and fans for free, and they are quiet.
So ultimately what i need to know is: Once having the powersupply, can you hook wires from that directly to a fan or two? If so... How??

This will help me heaps
Thanks Schmoke

no problem! the connector has 1 yellow wire, 1 red wire, and 2 black wires

yellow = 12v
red = 5v
black = ground

(this is standard and i've never seen anything different but just in case look on the side of the power supply, it will say which colored wire carries what voltage)

on the side of the power supply it will say how much power is available to each voltage (mine is 350w and supplies 10a worth of 12v power)

now, what you'll want to use are 12v fans they're about $2.50 each for 50ish cfm and about $5 for 80-100 cfm

once you're picked your fan either wire on a connector OR just cut the connector off the PS and hardwire the two together (i use connectors for ease of movement)

the only thing you should watch out for is that 12v fan may only have 2 leads (should be red(power) and black(ground)) so you're going to want to take the RED wire from the FAN and connect it to the YELLOW wire on the POWER SUPPLY

if you connect the RED wire on the FAN to the RED wire on the POWER SUPPLY you'll only get 5v to that fan and 5v is not enough to power a 12v fan

you would not believe the air movement potential one power supply has, the fans i will be using will draw 0.240 amps providing 46 cfm each @ $2.50 each

so if i max out this power supply (use all 10 amps) with JUST these fans i'll have 40 fans moving 1840 cfm for a total price of $100 for the fans

i know this isn't as efficent as a 1840 cfm blower, but try to find one of those for under $100

sure you can, there is no need for the fans to be IN the case or for the case to be IN your grow room (mine is in the room now to provide heat but in the summer i'm sure i'll have to move it out)

if you want to put it outside your grow room i'd recommend hard wiring an extention onto ONE of the leads from the power supply and just split it once inside the grow room 14 gauge wire will work fine for this application as well as extending the cord from your ballast to your light socket (assuming you put your ballasts in the case as well)

Thanks a lot dude
That has fully answered ALL my intake fan questions.
peace
Schmoke

can i strip down my computer power supply for my fan? its awfully big for a stealthy grow. yknow?