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How important is the fan in an atx computer power supply

Just wondering if having the fan in there is super necessary if it's only being used to power like 5v 300ma? I get that when running a CPU,board, multiple drives etc it would be necessary bcoz of the high current they're using but what if I was running just 300ma at 12v or smaller.would it overheat and burn out? I'm running one (small laptop hd only) but the fans noise is a problem and if unnecessary id like it gone.images.jpegthis is what I'm talking about
 

gophert

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Most Helpful Member
It should not be a problem for one hard disk.
You may, MAY, have trouble getting the power supply to run because they (generally) need a minimum load of about 500mA on the 5v rail to achieve a stable voltage regulation. No load on 12VDC rail is (generally) ok.

Good luck.

Also, the power supply may not work if it does not sense that it is spinning. The third wire to the fan (if connected) may have logic to sense if the fan is spinning. Worth trying before worrying. Just note that the supply may shutdown if it does not sense a spinning motor.
 

Reloadron

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Most Helpful Member
Just wondering if having the fan in there is super necessary if it's only being used to power like 5v 300ma?
Or you could buy a PSU without a fan, they are made specifically because of the problems of fan noise.
I am with Nigel on this. I can buy a 5 volt 1 amp wall wart for a few bucks on Amazon and be done with it. Any 5 volt as low as 500 mA phone charger would also work.

Ron
 

Pommie

Well-Known Member
Most Helpful Member
As I said, seems a cheap as possible solution seems to be the answer. Personally I'de buy the cheap 5V wall wart.

Mike.
 
Just to clarify I'll be using it for multiple things some being 12v some being 9v some 5v.i have plenty of phone chargers but can't run a hard drive off one.i have no intention of spending money on another atx without a fan I can get another one for $10 if I overheat this one.and I'm keen on using the fan elsewhere but without the blades.strange thing is the laptop hd says 5v700ma yet it's connected to
the 9+12v rails.
 

gophert

Well-Known Member
Most Helpful Member
the best way to determine if it works is to give it a try.
1) make sure you connect the green "power on" wire to ground. The easiest way is to bend a paper clip into a U and stuff it into the ATX connector.
2) add a 10 ohm, 10 watt resistor between 5v and ground (not needed if you are connecting a device that draws more than 500mA. Voltage Regulation will improve as you draw an amp or two.
3)once you are sure it works, try disconnecting the fan and try again.
 

Reloadron

Well-Known Member
Most Helpful Member
Just to clarify I'll be using it for multiple things some being 12v some being 9v some 5v.i have plenty of phone chargers but can't run a hard drive off one.i have no intention of spending money on another atx without a fan I can get another one for $10 if I overheat this one.and I'm keen on using the fan elsewhere but without the blades.strange thing is the laptop hd says 5v700ma yet it's connected to
the 9+12v rails.
With that in mind I would take gophert's suggestion and just try it.

Ron
 

dr pepper

Well-Known Member
Most Helpful Member
If you only need 5v @ 300mils you might be able to use the 5v standby part of the psu, it runs without the fan, check to make sure first that it can supply 300 mils of course.
 

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