Control: management of fans, temp/rpm monitoring via soft/hardware
Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee
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shunx
- Posts: 341
- Joined: Sun Oct 06, 2002 1:20 pm
- Location: Vancouver
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by shunx » Sat Nov 16, 2002 3:08 pm
Does anyone know the fan speed of a Panaflo 92mm (Low) at 5V?
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Renod
- Posts: 20
- Joined: Fri Nov 01, 2002 11:31 am
- Location: San Jose, CA USA
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by Renod » Sat Nov 16, 2002 5:48 pm
Volts_____Fan speed/noise
12__________100%
_7___________58%
_5___________42%
Just take the rated speed and multiply.
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shunx
- Posts: 341
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- Location: Vancouver
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by shunx » Sun Nov 17, 2002 5:57 am
oops forgot they were proportional... thanks
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ChiefWeasel
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by ChiefWeasel » Sun Nov 17, 2002 10:58 am
was wondering about this, and i think that they probably are proportional, but how do you know that the line would (theoretically) pass through 0RPM at 0V?
If its linear then it satisfies y=mx+c, where y=RPM and x=Voltage. How do you know that c=0? jus wondering...
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shunx
- Posts: 341
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by shunx » Mon Nov 18, 2002 1:46 am
maybe c could be negative if the fan stops before hitting 0v?
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ChiefWeasel
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by ChiefWeasel » Mon Nov 18, 2002 3:18 am
c could be negative, but i dont think that the fact that it stops before 0V would be the reason. y=mx+c is only valid when V is greater than the start up voltage. Below the startup voltage, RPM is clearly 0. Anyone have an RPM sensing fan they can use to find the RPM at 5,7,12V?
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shunx
- Posts: 341
- Joined: Sun Oct 06, 2002 1:20 pm
- Location: Vancouver
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by shunx » Mon Nov 18, 2002 3:58 pm
assuming my rheostat is working in accord with specs, my 92mm fan is running:
2500rpm at 11V (rated max voltage of rheostat; fan is rated at 2800rpm+/-10% at 12V)
1500rpm at 5V
1500rpm/2500rpm = 60%
5V/11V = 45%
That doesn't seem very linear, but if rpms include 10% error then the ratios may be closer.