Fan Control Availability

UaVaj

Golden Member
Nov 16, 2012
1,546
0
76
Instead of buying three 120mm PWM fan ($15 each / $45 total) and splitting the RPM signal from a single PWM header to control those three fan.

Is there a smart fan controller that recieved the RPM signal from the PWM header and then control three 120mm non PWM fan ($10 for all) via voltage regulation.

Thanks
 

UaVaj

Golden Member
Nov 16, 2012
1,546
0
76
thanks for that link, however that is not what I am looking for.

that is a manual enduser PWM control. looking for an automatic motherboard PWM control via PWM header RPM signal.

perhap no such device exsists.
 

tracerbullet

Golden Member
Feb 22, 2001
1,661
19
81
What is the end result that you are trying to get to?

If it is just RPM control over fans, 3 pin motherboard fan headers should be able to do that (the wires are power, ground, and RPM sense). Motherboard BIOS, or add-on software, can control RPM.

If you are trying to do something else, explain it and maybe there are other options.
 

EarthwormJim

Diamond Member
Oct 15, 2003
3,239
0
76
thanks for that link, however that is not what I am looking for.

that is a manual enduser PWM control. looking for an automatic motherboard PWM control via PWM header RPM signal.

perhap no such device exsists.

No, you should re-examine the link. That fan controller will accept a motherboard's PWM signal, and translate it to a proportional output voltage level. Between 6-12V depending on the duty cycle of the PWM signal.

It can also be controlled with the potentiometer (knob).
 

UaVaj

Golden Member
Nov 16, 2012
1,546
0
76
you are semi correct.

what that device does is - split the pwn header from the motheboard with an optional worthless manual control. all the current powering the fans is still coming from the motherboard header. hence the 20w max - hence two output headers.

that device is a fail. for that $13. for a little over the same money. might as well buy two PWM controlled fan and splice together. one less controller to fail.

-----

need a device that input the 12v directly from the molex. uses the RPM signal from the PWM header to control the output voltage. since the 12v is direct from the molex, current draw could be infinite.
 

EarthwormJim

Diamond Member
Oct 15, 2003
3,239
0
76
you are semi correct.

what that device does is - split the pwn header from the motheboard with an optional worthless manual control. all the current powering the fans is still coming from the motherboard header. hence the 20w max - hence two output headers.

that device is a fail. for that $13. for a little over the same money. might as well buy two PWM controlled fan and splice together. one less controller to fail.

-----

need a device that input the 12v directly from the molex. uses the RPM signal from the PWM header to control the output voltage. since the 12v is direct from the molex, current draw could be infinite.

It does more than split the signal, again you should read more about it. It can control non-PWM fans using a PWM signal. Based on the duty cycle it will output a DC voltage between 6-12 V. If all it was doing was splitting a PWM signal, it would have no way of controlling non-PWM fans.

If you're concerned about the power handling capabilities of your motherboard header, you can just get the 5.25 or 3.25 bay version of that controller. They derive their power from a molex connector (although you could power that PCI bracket with a molex too with some splicing).

3-channel version : http://www.amazon.com/Sunbeam-Rheosm...ds=rheosmart+3

What you're asking for requires actual circuitry, so of course it's going to cost some money. You need a dc-dc converter (Voltage regulator) of some kind to output the voltage you want below 12V, and you need an interpreter circuit to control the converter based on the PWM duty cycle.

So if you're looking to save money when you're just using 3 fans, that's not going to happen. If you were looking to control say 6 fans, then you might realize a discount.
 
Last edited:

coffeejunkee

Golden Member
Jul 31, 2010
1,153
0
0
you are semi correct.

what that device does is - split the pwn header from the motheboard with an optional worthless manual control. all the current powering the fans is still coming from the motherboard header. hence the 20w max - hence two output headers.

that device is a fail. for that $13. for a little over the same money. might as well buy two PWM controlled fan and splice together. one less controller to fail.

-----

need a device that input the 12v directly from the molex. uses the RPM signal from the PWM header to control the output voltage. since the 12v is direct from the molex, current draw could be infinite.

He is actually completely correct. But you didn't mention the molex requirement till now. It would also help if you answer tracerbullet's question, because right now it's not completely clear why you don't just use the mobo fanheaders.
 

UaVaj

Golden Member
Nov 16, 2012
1,546
0
76
total of 3 fan for cpu (push/center/pull) and 3 fan for case (two front, one back).

3 fan for cpu off the signal of the cpu pwm header.
3 fan for case off the signal of the case pwm header.

looks like some splicing will be necessary.

as for the manual control. who actually manually control the fan on a daily basis? do tell. IMHO - fan control is setup once and forget about it.

coffeejunkee - you do realize most motherboard only have one pwm header for cpu and fewer motherboard have another pwm header for case.
 

EarthwormJim

Diamond Member
Oct 15, 2003
3,239
0
76
He is actually completely correct. But you didn't mention the molex requirement till now. It would also help if you answer tracerbullet's question, because right now it's not completely clear why you don't just use the mobo fanheaders.

A majority of motherboards out there do not offer voltage control on their fan headers for non-PWM fans.
 

tracerbullet

Golden Member
Feb 22, 2001
1,661
19
81
do tell

you do realize

Only in this post did you actually explain what you're trying to do and how many fans you're trying to control. You'll be more likely to get help and ideas from people if you explain your goals and refrain from giving people crap for not being mind readers. Just an FYI.
 

coffeejunkee

Golden Member
Jul 31, 2010
1,153
0
0
total of 3 fan for cpu (push/center/pull) and 3 fan for case (two front, one back).

3 fan for cpu off the signal of the cpu pwm header.
3 fan for case off the signal of the case pwm header.

looks like some splicing will be necessary.

as for the manual control. who actually manually control the fan on a daily basis? do tell. IMHO - fan control is setup once and forget about it.

coffeejunkee - you do realize most motherboard only have one pwm header for cpu and fewer motherboard have another pwm header for case.

Yes, but you don't need pwm per se to control a fan. Many motherboards let you control 3-pin fans as well.

A majority of motherboards out there do not offer voltage control on their fan headers for non-PWM fans.

Most motherboards offer voltage control on at least 1 casefanheader, many on more than that. Don't automatically assume a 4-pin header uses pwm for control, some use dc, some pwm, and some both. Therefore it would be useful to know which motherboard is being used.
 

UaVaj

Golden Member
Nov 16, 2012
1,546
0
76
to simplify what is needed. pwm control dc-dc voltage regulator

36w/3amp rating. input voltage is 12v via molex. output is 4v-12v.
output voltage is regulated via PWM signal from motherboard header (not via manual potentiometer).

did find a few schematics to build one, be easier to just buy one.
 

EarthwormJim

Diamond Member
Oct 15, 2003
3,239
0
76
to simplify what is needed. pwm control dc-dc voltage regulator

36w/3amp rating. input voltage is 12v via molex. output is 4v-12v.
output voltage is regulated via PWM signal from motherboard header (not via manual potentiometer).

did find a few schematics to build one, be easier to just buy one.

I already gave you a link that meets this requirements. You're generally not going to find fan controllers that offer that much current on one channel.

Here it is again: http://www.amazon.com/Sunbeam-Rheosm...am+rheosmart+6

90W total between the three channels.
Very few fans start at 4V btw.
 
Last edited: