Lamptron fc5 v2 fluctuations

GJ02 · 16 Apr 2011 at 08:48

I hope someone can help me out here
Ive got a lamptron fc5 v2 in my new hafx case
all fans connected to the controller are working, but im not sure if they are working correctly.
fan rpm on the controller fluctuate +/-10 rpm's and the 200mm fan at the back that is rated at 700 rpm is only showing 640rpms
all the fans are rated at 700rpm with exception to the rear exhaust which is pluge in via molex and not connected to the controller
i have
1 230mm at front connected
2 200mm on top connected 1 running at rated 700 and one at 640 not 700
1 200mm on the side panel running at rated 700

any ideas as to why the fluctuation in rpms, and how to get the other fan running at rated rpms ?

Sayso · 16 Apr 2011 at 08:59

thats normal.

Ace Modder · 16 Apr 2011 at 10:09

fan RPM speeds can be +/- 10% anyway.

GJ02 · 16 Apr 2011 at 10:34

Ace Modder said:
fan RPM speeds can be +/- 10% anyway.

what about the reading of the 700rpm rated fan only doing 640 - 660 ?

Tealc · 16 Apr 2011 at 10:36

Fan controllers cannot put out the full voltage even at their maxiumum setting. Voltage regulation is a lossy method of reducing voltage and sometimes you can lose 1v or more depending on the transistors used in the fan controller's circuit. So a fan at 12v might lose a few hundred rpms as the voltage seen by the fan is effectively less than 12v.