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SOLVED will i have any problems with running a 5v fan at 12v

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M

mark

Guest
I ripped 2 40mm 5v fans with h/s off my 3dfx voodoo 5500 agp, (RIP).
I have connected the fans to my power supply just to see what would happen.
They spin, they spin real fast. They have some decent cfm now. They sound like a dust buster. And I like it.
With me running them at 12v instread of 5v will they burn-out faster or anything?
I'm thinking of running one on my Clock Generator, and one on my North Bridge "greenie" on my Asus p3v4x.
F3ar.
uh huh
mark
 

[Oc]acaridans

Senior Member
Joined
May 11, 2001
if the fans were made to run at 5v, feeding 12v would cause a problem, I doubt anything major would happen but im sure the fans would die quicker
 

Shadow ÒÓ

Mod in Hiding
Joined
Dec 20, 2000
Location
Pensacola, Florida USA
if the fan is meant to run at 5v and you run it at 12, you also run the risk of heating problems. Not just the motor getting hot but the leads to it........as well as overloading the mobo.

I wouldn't suggest it.
 

proze

Senior Member
Joined
Dec 22, 2000
Location
Pretoria, RSA
running them at 12v will burn them out quicker. check their amperage, and work out the power they'll draw to see if your mobo headers can take it.

otherwise running them in series is a good idea.
 
OP
M

mark

Guest
k the fans are 0.13A @ 5VDC so thats 0.65W each.
I only ran the one fan at 12V for about 15sec, so shush.
I have not used arctic silver adhesive, and would like to know if you guys have any tips.
and have any of you guys superglued a fan onto a h/s? (40-50mm)
any of you guys tinker with the northbrige chips before?
anyone stick a hs/f on the clock generator?
 

It_The_Cow

Senior Member
Joined
Apr 21, 2001
Location
Indiana
I'm sure many people have implemented active cooling on the northbridges. On some motherboards, cooling it may help to stabalize high FSB speeds
 

whiskeyinajar

Registered
Joined
Jul 1, 2001
just get a 12v fan and forget about this 5v stuff. id hate to see a system go up in smoke just because a little ol 60mm fan. the 5v fan WILL overheat and burn up if ran at 12v for extended periods. an overclocked proc is enough for your system an overclocked fan is just askin for trouble
 
OP
M

mark

Guest
overclocked fan, i think that's a new one.
thanks guys i'll prolly just run them at 5v or 7v. or get a few bucks and get some new fans, i dunno yet
 

cjtune

Member
Joined
Dec 18, 2000
There could be a chance that your Voodoo fans could be 12V fans being run at 5V in the first place. Most of the small DC fans in the manufacturers' catalogues I've seen are either 12 or 24V. I don't think they'll be making 5V specially for graphic cards. The old 40mm that came with my 486 was 12V.

Normally, if a voltage is excessive, the insulation of a electrical device would break down immediately, causing short circuits and the device would be toast from start, but since your [email protected] fans seem to be running fine, it's a good chance they are 12V fans.
 
OP
M

mark

Guest
i looked on the back of the fan which shows it is a 5v fan
 

cjtune

Member
Joined
Dec 18, 2000
It's your call now, mark. Running devices above a rated whatever, if it hasn't died immediately yet, will severely reduce the lifespan. But me thinks it's a 12V fan by built and how cheaply can they make a 5V compared to a 12V? Electromechanical motors depend on voltage for speed so if there's anything they can skimp on it's probably the capacitors or whatever electronic components inside the hub of the fan but most probably not the sleeve bearings as they are very simple components by nature. Go check out a fan manufacturer's website if you have the time.
 

cjtune

Member
Joined
Dec 18, 2000
Maestro (Jul 27, 2001 04:02 a.m.):
I have a bunch of 5v Fans laying around are there any URL for mods to 12v or 7v around ?

Maestro

Err, don't tell me you plan to mod those tiny PCBs in the hub of the fans... If you just need the extra speed just run them right away at 7V from the PSU power (or 12V, but cross your fingers in case they are REALLY 5V fans).
 
OP
M

mark

Guest
well to run a fan at 5v connect + to the red and - to the black.
to run it at 7v connect + to the yellow and the - to the red
to run it at 12v connect the + to the yellow and - to the black
+ is red on the fan, - is black on the fan.
 

*spazzed*

Senior Member
Joined
Dec 19, 2000
Location
hamilton, ontario, canada
I ran an electric motor that was rated at 1.5 volts, at 9.6 volts. Poor thing only lasted 30 min :D Give it a shot and see how long it will work, if it worked for aboout 15 sec. without getting hot, try it for abit longer. If you are worrying about blowing your PSU then try using a car battery instead :) (I seem to use a car battery alot :D )