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- From: bauer@informatik.uni-ulm.de (Christian Bauer)
- Subject: Re: Fan makes noise in Quadra 700!
- Message-ID: <bauer-120193150207@134.60.68.23>
- Followup-To: comp.sys.mac.hardware
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- Organization: University of Ulm
- References: <C0L4J1.5qz@lysator.liu.se> <Edward.Visse-120193125708@fastpath-24.wblab.lu.se>
- Date: Tue, 12 Jan 93 14:07:27 GMT
- Lines: 39
-
- In article <Edward.Visse-120193125708@fastpath-24.wblab.lu.se>,
- Edward.Visse@wblab.lu.se (Edward Visse) wrote:
- >
- > In article <C0L4J1.5qz@lysator.liu.se>, mll@lysator.liu.se (Thomas
- > Danielson) wrote:
- > >
- > > Anybody know if there is a way to make the fan in a Quadra 700 not
- > > so noisy? My machine is turned on for 24h/day and I have no
- > > accessory cards installed. Is there a temperature regulated fan out
- > > there somewhere that I could use?
- > >
- > > Thanks,
- > > /Thomas
- > > mll@lysator.liu.se
- >
- > The Atari ST used to have the same problem. The solution was to put in a
- > resistor in the power line to the fan (I think it was 25 Ohm, but I'm not
- > sure). You can try some different resistors, but be sure the fan is able to
- > start up though. If you want A temperature regulated one, they exist for
- > the Atari, but I don't know if they can be used directly in a Quadra.
-
- Shure a resistor is the cheapest solution, but it is a little bit
- dangerous,
- because on power on the fan needs much more power to start (6 Volt minimum
- for the better one) If you use a resistor this voltage can not be reached,
- so the fan stands still and gets very hot.(the resistor too!) So the
- better solution is to put in a Z-diode of about 3 to 6 Volt (for 12 Volt
- fan)
- so the starting voltage of 6 volt is shure.
- But the best solution I have seen is to put in a microcontrolled silent fan
- from Papst (or other vendors) which measures the temperature and according
- to this value it controls the fan with pulse modulation (so even very
- slow rotation can be implemented). And if the mac needs more power, the
- fan spins faster to prevent overheating of your expensive 68040!. (this
- fan is about 20 to 35 $ but it is very quite!)
-
- Christian Bauer
-
- bauer@informatik.uni-ulm.de
-