Below 5V.. possible?

everydae · Post by **everydae** » Sun Feb 22, 2004 8:54 pm

I recently got Titan AL12025 120mm aluminium-frame fan, which is actually Evercool. However, I didn't know it's 'H' until I got them, so it's pretty loud even at 5V (more air sound than my Antec fan@12V, which came with Super Lanboy). What I want to know is if it is possible to mod below 5V, maybe around 4V. Anyone have good idea to mod?

kesv · Post by **kesv** » Mon Feb 23, 2004 2:56 am

everydae wrote:What I want to know is if it is possible to mod below 5V, maybe around 4V. Anyone have good idea to mod?

Certainly it's possible. Maybe you could connect a fanmate to the 5V rail ? Note: I haven't done this with a real psu.

If you want to try it, I suggest you pay attention to the voltage at which the fan stalls. One of the best in this respect in my testing was surprisingly the Antec fan, which still runs at about 2.5V. And one of the worst was the Nexus 80mm, which didn't run reliably under 7V. Although the Nexus moves so little air under 7V that you really don't want to run it that low anyway.

clive · Post by **clive** » Mon Feb 23, 2004 3:42 am

I have the H model evercool and have it and the cpu fan controlled by SpeedFan.

It stalls at 20% but will run at 25% but it needs 50% to kick start it, I do not know how accurate these reportings are. Its reasonably quiet at 25% and zero noise at 20%! he loudest noise is the Zalman.

FWIW the Zalman 7000 runs at 5% (although it show 0 RPM) which seems to be its lowest setting without stalling.

Currently running a P4c 2.8 at 3.2 and it idles at 45C and goes to 56C under CPUBurn, ambient is 24C.

silvervarg · Post by **silvervarg** » Mon Feb 23, 2004 12:33 pm

Kesv:
Certainly it's possible. Maybe you could connect a fanmate to the 5V rail ? Note: I haven't done this with a real psu.

I would not recommend that idea.
The fanmate tries to give out a certain voltage depending on the dial, regardless of the input voltage. Driving the fanmate on 5V should make the dial more or less useless and the output would be somewhere close to 5V.
A better option is to solder a resistor on the red wire of the fan. Something like 50-80 ohm should be a good value. The use a fanmate or other controller to set the voltage.
Note that you are effectively shifting the min and max voltages downwards with the resistor, so you can no longer run that fan at a full 12V.

everydae · Post by **everydae** » Mon Feb 23, 2004 6:48 pm

How about using Diode? Would it work?

al bundy · Post by **al bundy** » Mon Feb 23, 2004 11:27 pm

You could put one of these 56 ohm resistors between the fanmate and the fan...

silvervarg · Post by **silvervarg** » Tue Feb 24, 2004 12:32 am

Everydae:
How about using Diode? Would it work?

Yes, it will work fine.
Depending on the diod(s) you use you usually get a voltage drop of 0.7 to 1.0V per diods.

Maurizio XP · Post by **Maurizio XP** » Tue Feb 24, 2004 1:16 am

I'm using a zalman cnps7000 with a 5v rail + zalman fanmate conncted and it removes all the noise of the fan.

Jan Kivar · Post by **Jan Kivar** » Tue Feb 24, 2004 9:20 am

silvervarg wrote:The fanmate tries to give out a certain voltage depending on the dial, regardless of the input voltage. Driving the fanmate on 5V should make the dial more or less useless and the output would be somewhere close to 5V.

Actually, I played a bit with my two unused/available FanMates. A FanMate will output about 1.5V lower than the input voltage, if the dial is at max. So by connecting a FanMate to 5V rail, You'd get about 3.5V.

Do note that there will be no adjustment; IIRC the voltage went up a bit (say less than ~0.2V) when the dial was at min.

Cheers,

Jan

yermolovd · Post by **yermolovd** » Tue Feb 24, 2004 9:14 pm

I have Zalman 7000AlCu through Fanmate and to Zalman controller at min. works fine for 2 weeks already. RPM is 1040-1090.

Below 5V.. possible?

Below 5V.. possible?

Re: Below 5V.. possible?