Max power allowed for AN8 Ultra fan headers

I have a Abit AN8 Ultra motherboard, I want to put it
in my Gigabyte 3D Aurora tower case. The Aurora has two
12cm fans in the back that are connected in parallel to
a single 3 pin header wire that you are supposed to
plug into a motherboard fan header. It seemed to me
that two fans might take more power out of the header
than Abit designed the headers for. Would that be a problem?

Looking at over some other 12cm fans I see on other
web sites, they would take about 150mA
or maybe 250mA at 12Volts? So if the header can supply
0.5 Amp I'd be ok?

Mark

So with the two fans connected in parallel, the center pin on the 3
pin header has no wires connected to it and therefore you will not be
able to sense their speed ?

Forrest

Motherboard Help By HAL web site:
http://home.comcast.net/~mobo.help/


On Sun, 27 Nov 2005 03:02:00 GMT, Ed Zeppelin
wrote:


I have a Abit AN8 Ultra motherboard, I want to put it
in my Gigabyte 3D Aurora tower case. The Aurora has two
12cm fans in the back that are connected in parallel to
a single 3 pin header wire that you are supposed to
plug into a motherboard fan header. It seemed to me
that two fans might take more power out of the header
than Abit designed the headers for. Would that be a problem?

Its possible but I wouldn't expect it to be a problem.


Looking at over some other 12cm fans I see on other
web sites, they would take about 150mA
or maybe 250mA at 12Volts? So if the header can supply
0.5 Amp I'd be ok?

From the descriptions I've heard, the total (static) current isn't
normally a problem. The problem can be (1) the (ac electrical) noise
from the fans or (2) the initial start-up current of the fans. DC
fans consume about five times more current when they start then they
do when running.


Mark

- HAL9000 wrote:

So with the two fans connected in parallel, the center pin on the 3
pin header has no wires connected to it and therefore you will not be
able to sense their speed ?

Forrest

Motherboard Help By HAL web site:
http://home.comcast.net/~mobo.help/

No, what Gigabyte did was to have one of the two fans RPM signal
wires go to the signal pin on the motherboard header. The second
fan is only connected to the +Vcc and Ground. The idea is that
since the fans are pretty much the same, the RPM of either will
be about the same as the other since they're wired parallel (same
voltage applied to both).
Mark


On Sun, 27 Nov 2005 03:02:00 GMT, Ed Zeppelin
wrote:


I have a Abit AN8 Ultra motherboard, I want to put it
in my Gigabyte 3D Aurora tower case. The Aurora has two
12cm fans in the back that are connected in parallel to
a single 3 pin header wire that you are supposed to
plug into a motherboard fan header. It seemed to me
that two fans might take more power out of the header
than Abit designed the headers for. Would that be a problem?

Its possible but I wouldn't expect it to be a problem.


Looking at over some other 12cm fans I see on other
web sites, they would take about 150mA
or maybe 250mA at 12Volts? So if the header can supply
0.5 Amp I'd be ok?

From the descriptions I've heard, the total (static) current isn't
normally a problem. The problem can be (1) the (ac electrical) noise
from the fans or (2) the initial start-up current of the fans. DC
fans consume about five times more current when they start then they
do when running.


Mark