Questions about manual speed control of fans

Control: management of fans, temp/rpm monitoring via soft/hardware

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ermi
Posts: 83
Joined: Mon Jun 16, 2008 6:00 am
Location: eu

Questions about manual speed control of fans

Post by ermi » Thu Oct 14, 2010 11:05 am

I have a GMC H-60 PC case, which has two 12 cm case fans, whose speed is controlled manually with two controls on the side.
The fans are too loud, so I'll replace them with two other 12 cm ones, perhaps two Slip Streams. Now I have some questions on properly replacing the fans (to still have the ability to manually change fan speed).

Let me describe what I have now (the default fans). Here are the wires from one of the fans:
Image

The red and black wire go to the Molex power adapter..
Image

...while the black and yellow go to the speed/voltage control cables..
Image

..which end in this pair of front/rear controls:
Image
(The only thing written on those things is JASON.)


Now, the questions:

1. If I buy a regular non PWM fan, will it have the equivalent 3 wires, which I could wire up to the case controls?
2. Are there any elegant solutions, or am I left to cutting and twisting various wires together? (shouldn't be too difficult anyway)
3. If I buy a fan that's rated at 1200 rpm, what will be its maximum and minimum speed when I use those controls?
4. If I don't use the controls, but connect the fans directly to the 3 pin connections on the MB, will they always run at full speed?

If there's anything else I should consider please let me know. The fans will probably run at the lowest speed most of the time, so I'm still considering the option to not even bother with controls and just buy some quiet 800 rpm Slip Streams.. but it seems a bit of a waste to not use those controls since they are already there.

themaster1
Posts: 95
Joined: Fri Apr 23, 2010 9:01 pm
Location: Southern France

Re: Questions about manual speed control of fans

Post by themaster1 » Fri Oct 15, 2010 2:18 am

ermi wrote:1. If I buy a regular non PWM fan, will it have the equivalent 3 wires, which I could wire up to the case controls?
The fans you have are non PWM it seems (PWM = 4 pins), yours are only 2 pins.3pins is also non pwm
ermi wrote:2. Are there any elegant solutions, or am I left to cutting and twisting various wires together? (shouldn't be too difficult anyway)
???
ermi wrote:3. If I buy a fan that's rated at 1200 rpm, what will be its maximum and minimum speed when I use those controls?
You can only know when you buy the fan and read the specs on the manufacturer's website.
ermi wrote:4. If I don't use the controls, but connect the fans directly to the 3 pin connections on the MB, will they always run at full speed?
Yes, FULL speed, maybe 60-75% speed if you use a 7/9V LNA cable but certainly not its lowest possible speed (about 30% i believe)
ermi wrote:so I'm still considering the option to not even bother with controls and just buy some quiet 800 rpm Slip Streams
Maybe your best option then

ermi
Posts: 83
Joined: Mon Jun 16, 2008 6:00 am
Location: eu

Re: Questions about manual speed control of fans

Post by ermi » Fri Oct 15, 2010 8:46 am

I'll probably just get some PWM fans for now, since I'll be using SpeedFan for the CPU anyway.. in case I decide to start using these manual controls I can always do this even with PWM fans. (I'd just ignore the 4th wire, I guess.) But any other thoughts on this are still welcome.

loimlo
Posts: 762
Joined: Thu May 03, 2007 3:58 am
Location: Formosa

Re: Questions about manual speed control of fans

Post by loimlo » Sat Oct 16, 2010 9:50 am

Frankly, I don't think it's a good idea to control PWM fans using voltage control. Usually, PWM fans respond to DC voltage disproportionally as they are designed to be controled by PWM signal. For example, some PWM fans may stop working below 9V voltage, leaving you little room for PWM fan control.

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