EDIT** Fan in an Fortron 350 (more confusion)

PSUs: The source of DC power for all components in the PC & often a big noise source.

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RedSnapper
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EDIT** Fan in an Fortron 350 (more confusion)

Post by RedSnapper » Mon Apr 04, 2005 3:05 am

Hi, has anyone tryed a Antec Tricool 120mm in an Fortron 350 (currently has a ~70cfm Yate Loon ball bearing). My thinking is that I could run the Tricool on medium setting (and high or low for extreme conditions):

39 CFM (1200 rpm) 25 dBA
56 CFM (1600 rpm) 28 dBA
79 CFM (2000 rpm) 30 dBA

What do you think, worth doing?

Also, I think I read somewhere that using an inline 'diode' doesn't work with the Fortrons as it controls fan speed by Amps (not volts), would that be the case with Tricool? I'm a Bit confused about that.

(System - xp2800, 1Gb, 6600gt, 2xHD)
Last edited by RedSnapper on Tue Apr 05, 2005 12:16 pm, edited 1 time in total.

sthayashi
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Post by sthayashi » Mon Apr 04, 2005 4:42 am

Why exactly wouldn't inline diodes work on an 'Amp'-based method of fan regulation (really just a potentiometer). Inline diodes will drop the voltage no matter what, and that voltage by default will reduce the current draw of the fan.

RedSnapper
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Post by RedSnapper » Mon Apr 04, 2005 8:12 am

No idea :shock: - I'm no spark :wink:

It's just something I read (this forum I think). Someone mentioned that the Fortrons fan speed is regulated in a a way a diode wouldn't work. Maybe it reads the returning (negative) wire or something (something... being beyond my limited understanding)?

EDIT : OK I've searched but can't find what the hell I'm talking about. Noticed another Fortron mod using a diode'd Acoustifan so I guess I'm mis-informed or my memory is playing tricks.

Aleksi
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Post by Aleksi » Mon Apr 04, 2005 9:11 am

The Fortrons have a current controlled PSU fan control. Regarding the use of diodes this is all the same. I'll try to explain with some simplified electronics basics:

Ohm's law: V = I R (Voltage = Current * Resistance)

For example, you have a fan that has a resistance of 120ohms. If your voltage feeding fan header feeds it 12V, according to Ohms' Law it has a current of 0.1A (100mA).

Now, if you have a fan controller that controls the current, it still stays the same. if the the controller feeds 0.06A and the resistance is the same 120ohms, the fan runs at 7.2V. If it gets 0.1A, the fan runs at 12V.

If you use a diode, the voltage is still dropped, whether the PSU uses a current/voltage source for the PSU fan(s).

RedSnapper
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Post by RedSnapper » Mon Apr 04, 2005 10:24 am

Thanks for explaining that Aleksi! Probably took me longer to understand it than you to write it, but I've the gist of it now.

RedSnapper
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Post by RedSnapper » Tue Apr 05, 2005 12:32 pm

Next question (sorry to pester). I have the Fortron 350 PF version that runs at a slighty higher RPM on the controller than the non PF (according to SPCR posts). The fan is a Medium Ball Bearing Yate Loon at 70CFM/1600RPM.

If the non PF runs its fan slower then I'm guessing I can put a slower fan in the PF version (as long as it isn't put under heavy load).

So, as to which fan... I have a spare Antec Tricool that runs 56CFM/1600RPM on the medium setting, but that's the same RPM as the Yate Loon, but with lower CFM :shock:

So, should I be looking for a slower fan, like 1200RPM (Maybe the Tricool on Low setting)?

Shouldn't 1600RPM give the same'ish CFM regardless of manufacturer?

Aleksi
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Post by Aleksi » Tue Apr 05, 2005 12:42 pm

Hi Redsnapper,

no need to be sorry for asking, that's why these forums exist. Have you checked the PSU modding sticky? Reading that should answer your guestion ;)

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