Can the famous 550w AcBel...

[gdement]

Re: Can the famous 550w AcBel...

5V is probably marginal for a 12V fan to be able to run. That's one reason many people prefer to do the 7v trick.
On the datasheets I've seen so far (admittedly all from the same manufacturer) they spec their 12v fans to tolerate 6v-13v.

Personally, my ideal fan would be capable of causing a tornado if necessary, but run quietly unless/until it actually needs to speed up. Unfortunately I don't think you can get much speed range without PWM support, and my board is too old for that.

[ratdude747]

Re: Can the famous 550w AcBel...

≠means not equal to

i was not repeating what you said, i was stating my thoughts. why go all the work to undervolt? im not goint o make a computer louder just to make it louder, but i have a pet peeve of computers running warm. even with tons of fans, they really do not get very loud. about as loud as a loud whisper.

like i said with my power supply, it alway blows out hot air but the fan bareley blows anything. how hot must it get to act? so hot it burns the house down?

[weirdlookinguy]

Re: Can the famous 550w AcBel...

I didn't say you were repeating anything.

You seem to think quiet computers are stupid, bound to fail, and that everybody should just run them nice and loud. I found this offensive because your iPhone and people-who-undervolt-fans comments insinuate that people who want quiet computers are idiots.

You know Ratdude, it's OK to have preferences different from others. You'd rather run a loud, cool computer than a quiet, warmer machine. That's fine. But don't start talking shit on those who would rather run their machines quiet. It's a personal preference, and just because the need/preference for a quiet computer doesn't apply to you doesn't mean it doesn't apply to anyone else.

[acstech]

Re: Can the famous 550w AcBel...

Wow that exploded.

My preference is to have enough cooling to get the job done and still be quiet. I use fan control mainly to extend fan life. In the computers I build for my customers, I base fan speed on CPU temperature. The BIOS in Biostar boards makes that easy. Then, I pair that with a heatsink with a large quiet fan. One that's still relatively quiet at full speed. Also, I use one of the lower flowing 120mm Panaflo's for an exhaust fan, also with speed control. I set it up so the CPU temp never goes much above 50c at full load. My computers stay cool and quiet, with long fan life. If my customers live in a hothouse, that's fine, the fans just speed up a bit. If they live in a deep-freeze, they might not even turn on. I personally like thermostatic fan control, so long as it's done right. IMO the AcBel does it right.

That's just the way I do it; I'm not suggesting that's the only way to do it.

[momaka]

Re: Can the famous 550w AcBel...

i accidentally undervolted a 80mm to 5v and it barely did anything

If it's one of those 0.14amp general crapola fans from a cheap PSU, they're bound to do that. The reason why is because they are designed to run on very little current at 12v (hence the low CFM rating). Cheap PSU manufacturers do that so they won't have to spend money on making a speed controller for the fan. Moreover, these low-CFM fans are cheaper as well. But the negative side of this cost-saving technique is that the fan quickly wears out and gets clogged with dust.
Good PSUs have a speed controller and a strong fan that runs at low speed when the PSU is cool and higher speed when it gets warmer. Like acstech noted, this extends fan's life and makes it quiet - if the speed controller is done right, that is. With good PSU manufacturers like AcBel, Delta, Lite-ON, and Seasonic, you bet it is.

Wow that exploded.

Yeah, I was just wondering whether I should put some popcorn in the microwave .

[ratdude747]

Re: Can the famous 550w AcBel...

then why does my delta always blow hot air yet the fan is running so slow.

[ratdude747]

Re: Can the famous 550w AcBel...

besides, how do you undervolt fans? solder in a resistor? sounds like a lot of work

[370forlife]

Re: Can the famous 550w AcBel...

Delta never really steps up the fan much in their psu's because they use good quality parts that can take more heat. They usually keep them from revving up until they get really hot, usually around 45C (hotter than you may think)

You can undervolt a fan with a few tricks, one is to just buy a fan speed controller on newegg or something for about $15. They have decent ones that can control 7 fans for about $40. There is also a way to use the -5v and a 12v to get 7v. I forgot how to do it exactly, but it is not very useful on a lot of fans or higher amperage fans due to the low amperage on the -5v.

[acstech]

Re: Can the famous 550w AcBel...

Your delta probably blows hot air because it's being controlled to a specified temperature while minimizing noise.

How do you undervolt fans? Look up "fan controller" on Newegg. Here's an example, not that I've used this particular product:

http://www.newegg.com/Product/Produc...82E16811998064

The problem with simple undervolting of fans is that airflow does not change with temperature, unless you physically turn a knob. It's only a compensation for buying too loud of fan to begin with.

If you're skilled with soldering, this article may be interesting:

http://www.bit-tech.net/modding/2001...n_controller/1

Edit: 370, you posted while I was still typing.

[momaka]

Re: Can the famous 550w AcBel...

then why does my delta always blow hot air yet the fan is running so slow.

I wouldn't be too worried about it because I'm sure Delta did a good job on the design. This is also why you see them use Ltec, CapXon, and other inferior brands of caps in some of their PSUs without having problems.
----
As for undervolting fans, you should only do that for powerful fans that don't need to run on full power (such as case fans - if you case is cool enough that is).
If there's a Micro Center near you, they have a simple single-fan controller for $4.
The other way to do it is with a resistor(s) in series with the fan. The resistance will depends on the amount of current the fan uses. Usually 20 to 100 Ohms should do the job, but you'll have to experiment to get the desired speed. The resistor wattage should also be picked accordingly.
Third way is to use a combination of the postive rails. For exaple, if you plug the negative fan wire in 5v and the positive in 12v, the net difference will be 7v, hence the fan will run as it would on 7v. But I think someone had something against that in another thread.
----
Sorry for the off-topic stuff above.

[weirdlookinguy]

Re: Can the famous 550w AcBel...

besides, how do you undervolt fans? solder in a resistor? sounds like a lot of work

So you're bitching about people who undervolt fans, yet you don't even know how it's done and dismiss it because it sounds like "a lot of work"? I thought the reason you were talking shit on not running everything full blast was because you wanted fans running at their highest potential, not because you're too lazy to run them any other way.

----------------------

acstech, the way you described it sounds right to me. Revs up just a bit under really heavy load. I just can't stand it when it's constantly switching speeds.

[ratdude747]

Re: Can the famous 550w AcBel...

i like to get full potential out of fans, i was just curious how it was done.

power supply no longer blows hot air. my homemade round ide cable gave it better air flow and it runs cool.

by turning off smart fan control, my p4 presscot 630 puts out 43-44c under moderate load (upgrading to ubuntu 9.10 alpha2). no front vents. no good hd airflow but the drive runs kinda warm (if remote temp. means the hd, then 32c). board runs 34c.

[ratdude747]

Re: Can the famous 550w AcBel...

ignore that last post, i was too slow on editing it.

try this one instead:

i like to get full potential out of fans, i was just curious how it was done.

power supply no longer blows hot air. my homemade round ide cable gave it better air flow and it runs cool. i made the cable by twisting a ribbon cable a bunch of times until it was constantly round and then i put a zip tie about every 2 inches. ugly but cheap and functional

by turning off smart fan control, my p4 presscot 630 puts out 43-44c under moderate load (upgrading to ubuntu 9.10 alpha2). no front vents. no good hd airflow but the drive runs kinda warm (if remote temp. means the hd, then 32c). board runs 34c.

my readouts:



i have one 80mm case fan in back. out of an old antec psu. it had tach. wire so i spliced in a cable from a smashed fan.

case is a cramped emachines t5026 with upgraded cpu, psu= delta dps-35ab-0 A rev. 03 F. all cd drives moved as forward as possible. i custom wited the psu so all it has is 2 "strands" -one is atx 12 4pin, the other has:

2x 2-connecor SATA (one ziptied off so it heads towards hd bays), atx 20+4, 2-connector molex. all connectors spaced so no extra bunched up wire, uses a ton of small zipties. all drive pwr cables come from a a buch of strands out of power supply, then branched out form a point on mobo cable using zipties/wire nuts. i used wire nuts so i can easily add/remove cables as needed.