Case Fan Wattage

[Da Whip]

Here is a question for the Electricians and such.
If I have a fan that normally uses 6.7watts @ 12V, what would the wattage be at 7V. Is it linear, if so the wattage would be 3.8. Please correct me if I am wrong. I am building a Rheobus for a freind and don't want to toast it after all this work.

[Dougthebug]

Heres the basic formulas:

V=IR (volts = amps * resistance) and P=IV (watts = amps * volts)

So as long as your using a rheostat/resistor/voltage regulator you shouldn't have any problems.

One thing to note though, some fans won't start with less than 9v.

[Da Whip]

9 volts is not a problem. I already got this system wired at 7 volts, but using 2 - 120mm high output Sunon's is killing his wifes ears.
Thanks for the input.

[Sohryu Asuka Langley]

aT lease they dorwn out the sound of a Delta like they do for my system.