120mm fan question

godfoot · 09-April-04, 01:20 AM

ok, I just procured from work from a junk system a 120mm Comair Rotron (a KLI company) Flight II fan. The only problem I see with it is that it is a 24 volt fan (.15 amps, 3.6 watts) rather than 12 volt. I am about to do some Googling on it but was curious if any of you folks knew if I could make it work with an ATX PSU.

j-dogg · 09-April-04, 01:27 AM

not too sure, but I do know those Rotrons have some sick flow, get them all the time at work and it's my job to test them. once we rigged some wheels on one and ran it at 30 volts at like 4 watts and it pushed itself across the floor

godfoot · 09-April-04, 01:44 AM

yeah, I went to their website and apparently my model number is no longer made but the closest comparable model I could find pushes 90CFM.

Sparky · 09-April-04, 01:47 AM

Take a +12v wire form a molex and connect to the + pin on the fan. then take -12v from the ATX-plug and connect to - on the fan. the -12v is blue, according to this: diagram. Also ive done some reading around and because that fan would draw soooo much current it might make your psu trip or just shutdown at startup if its trying to power that fan at full load. You might wanna consider putting a rheostat on it or a 3 way switch(24v OFF 12v), and have it in the 12v position for startup and once its spinning at full then switch it to the 24v. Its alot easier on your psu that way and you wont lose any components just by trying to push more air.

Spc. Forces Bob · 09-April-04, 01:49 AM

well, if its a 24votl i think you could run it in your comp it will jsut run slower and less cfm, DONT try this till you look into it though, but it shouldnt hurt anything.

godfoot · 09-April-04, 01:57 AM

Quote:

Originally Posted by Sparky


	Take a +12v wire form a molex and connect to the + pin on the fan. then take -12v from the ATX-plug and connect to - on the fan. the -12v is blue, according to this: diagram. Also ive done some reading around and because that fan would draw soooo much current it might make your psu trip or just shutdown at startup if its trying to power that fan at full load. You might wanna consider putting a rheostat on it or a 3 way switch(24v OFF 12v), and have it in the 12v position for startup and once its spinning at full then switch it to the 24v. Its alot easier on your psu that way and you wont lose any components just by trying to push more air.

I have taken that into consideration as I have some electronics background from the Navy (most of which I have since forgotten, unfortunately). I am looking at 24 volt PSUs right now anyone have any suggestions in that department?
Thanks for the info Sparky.

Sparky · 09-April-04, 02:32 AM

If i were you i wouldnt even bother wasting my money on a 24v psu when you can just get some generic piece o crap psu and make it 24v. That and youll have a new paperweight that will be accesible to test new components on the ready. What was your rate in the navy? Im an AE right now, but plan on striking civilian when my time is up.

godfoot · 09-April-04, 02:41 AM

I was an EW, although on the operator rather than the technician side so I only had to do the basic electronics school (AC, DC, power supplies).

Sparky · 09-April-04, 02:44 AM

Bah, just another shoe.....hehe just teasin man. Thats some heat movin around on that boat, and i thought it was bad gettin hit by aircraft power.

godfoot · 09-April-04, 02:54 AM

yeah the MMs were REQUIRED to take breaks every 30 minutes when standing watch in the engine room....hotter than hades down there.

MaTtsPc · 20-April-04, 08:15 PM

yes it will work ive done it before ! it will run like a champ ! u can run 5 v to it its just goin to run slower ! that 24 volts just means it u can run 24 vlots to it ! u can prolly run about 30 to it for about 4 mins an it would fry! but u can under volt dc anytime ! AC is what u cant under volt some stuff AC will die if u undervolt!

what do u think a fan controler does! all a fan controler is, is a inline variable resistor that cuts your fan from 12Volt to about 7Volt! it would be just like that but u are just running less power to it !

Spectrum · 20-April-04, 08:48 PM

hmm, id it takes 24, hook up 2 12 volt sources, or if if you want it a bit slower, a 12 and a 5 volt. i rigged a 12volt fan upto 17 volts and it screamed! yours will actually work properly that way.

nev_payne · 21-April-04, 05:24 AM

sounds intresting, yeh so long as its DC ull be fine on 12 - hell you'll get 45CFM out of it, and as its 120mm, it'll be deadly silent compared to most 80mm that push the same amount.

try running it off a spare PSU (at or atx) and see how it goes - run it for a couple of hours and check for the motor heating up or smoke

- those 2 things generally being quite the oposite of good.

Sparky · 21-April-04, 06:05 AM

Here i thought this thread died on the 8th?...... Oh well good inputs guys

godfoot · 21-April-04, 09:31 AM

Yes, you can consider this thread officially dead now as I hooked the fan to the yellow and black wires from a molex (old adapter had 2 pins that plugged into molex). It does work with no apparent strain on the PSU but the cfm took a performance hit so I am not going to be using it for the front of the case.
It may suffice as a blowhole fan though once I get a 120mm to place in the front.
Hmmmmm, Lokie I may need that fan after all.

09-April-04, 01:20 AM		#1 (permalink)
godfoot A George Orwell fan...sorta	120mm fan question ok, I just procured from work from a junk system a 120mm Comair Rotron (a KLI company) Flight II fan. The only problem I see with it is that it is a 24 volt fan (.15 amps, 3.6 watts) rather than 12 volt. I am about to do some Googling on it but was curious if any of you folks knew if I could make it work with an ATX PSU.

20-April-04, 08:15 PM		#11 (permalink)
MaTtsPc Apex Tech God	yes it will work ive done it before ! it will run like a champ ! u can run 5 v to it its just goin to run slower ! that 24 volts just means it u can run 24 vlots to it ! u can prolly run about 30 to it for about 4 mins an it would fry! but u can under volt dc anytime ! AC is what u cant under volt some stuff AC will die if u undervolt! what do u think a fan controler does! all a fan controler is, is a inline variable resistor that cuts your fan from 12Volt to about 7Volt! it would be just like that but u are just running less power to it ! Last edited by MaTtsPc; 20-April-04 at 08:24 PM..

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09-April-04, 01:27 AM		#2 (permalink)
j-dogg Mystical Schwinn Guru	not too sure, but I do know those Rotrons have some sick flow, get them all the time at work and it's my job to test them. once we rigged some wheels on one and ran it at 30 volts at like 4 watts and it pushed itself across the floor

09-April-04, 01:44 AM		#3 (permalink)
godfoot A George Orwell fan...sorta	yeah, I went to their website and apparently my model number is no longer made but the closest comparable model I could find pushes 90CFM.

09-April-04, 01:47 AM		#4 (permalink)
Sparky Apex Tech God	Take a +12v wire form a molex and connect to the + pin on the fan. then take -12v from the ATX-plug and connect to - on the fan. the -12v is blue, according to this: diagram. Also ive done some reading around and because that fan would draw soooo much current it might make your psu trip or just shutdown at startup if its trying to power that fan at full load. You might wanna consider putting a rheostat on it or a 3 way switch(24v OFF 12v), and have it in the 12v position for startup and once its spinning at full then switch it to the 24v. Its alot easier on your psu that way and you wont lose any components just by trying to push more air.

09-April-04, 01:49 AM		#5 (permalink)
Spc. Forces Bob Apex Elite Expert Tech	well, if its a 24votl i think you could run it in your comp it will jsut run slower and less cfm, DONT try this till you look into it though, but it shouldnt hurt anything.

09-April-04, 02:32 AM		#7 (permalink)
Sparky Apex Tech God	If i were you i wouldnt even bother wasting my money on a 24v psu when you can just get some generic piece o crap psu and make it 24v. That and youll have a new paperweight that will be accesible to test new components on the ready. What was your rate in the navy? Im an AE right now, but plan on striking civilian when my time is up.

09-April-04, 02:41 AM		#8 (permalink)
godfoot A George Orwell fan...sorta	I was an EW, although on the operator rather than the technician side so I only had to do the basic electronics school (AC, DC, power supplies).

09-April-04, 02:44 AM		#9 (permalink)
Sparky Apex Tech God	Bah, just another shoe.....hehe just teasin man. Thats some heat movin around on that boat, and i thought it was bad gettin hit by aircraft power.

09-April-04, 02:54 AM		#10 (permalink)
godfoot A George Orwell fan...sorta	yeah the MMs were REQUIRED to take breaks every 30 minutes when standing watch in the engine room....hotter than hades down there.

20-April-04, 08:48 PM		#12 (permalink)
Spectrum Former GameApex Editor	hmm, id it takes 24, hook up 2 12 volt sources, or if if you want it a bit slower, a 12 and a 5 volt. i rigged a 12volt fan upto 17 volts and it screamed! yours will actually work properly that way.

21-April-04, 05:24 AM		#13 (permalink)
nev_payne Apex Tech God	sounds intresting, yeh so long as its DC ull be fine on 12 - hell you'll get 45CFM out of it, and as its 120mm, it'll be deadly silent compared to most 80mm that push the same amount. try running it off a spare PSU (at or atx) and see how it goes - run it for a couple of hours and check for the motor heating up or smoke - those 2 things generally being quite the oposite of good.

21-April-04, 06:05 AM		#14 (permalink)
Sparky Apex Tech God	Here i thought this thread died on the 8th?...... Oh well good inputs guys

21-April-04, 09:31 AM		#15 (permalink)
godfoot A George Orwell fan...sorta	Yes, you can consider this thread officially dead now as I hooked the fan to the yellow and black wires from a molex (old adapter had 2 pins that plugged into molex). It does work with no apparent strain on the PSU but the cfm took a performance hit so I am not going to be using it for the front of the case. It may suffice as a blowhole fan though once I get a 120mm to place in the front. Hmmmmm, Lokie I may need that fan after all.