View Full Version : make my fan go faster!!!
Well i bought this chepo fan that goes only at about 2000 rpm. Now can I make it go faster because it is heat controlled. The wires coming out of it are black, red and yellow which go to the 3 pin connector and 2 white wires which go to the resistor like thing which i an guessing is the heat sensor. Now, the fans max speed is 5000 rpm but i can't get to that speed beacuse the heat sensor needs to detect a temp of 85 Degrees Celcius to do this. Is there any way i can wire that fan to run at its max speed of 5000 rpm without it actually being 85 degrees Ceicius. Also is there any way that i can increase that fan's speed by upping the amperage or voltage or something to amke it go beyond 5000 rpm?
does the fan work with the sensor disconected?
i have no idea because i can't disconnect the sensor. Its soldered on.
well you could try snipping one of the wires or unsoldering it to see, it can always be re-conected
ok i'll give that a shot.
nope when i disconnect the wire, the case fan stops. now what?
Well the only other thing I could suggest short of disasembling the fan to see how the temp monitoring syetm works is to by-pass the actual probe and just try creating a circuit with the 2 white wires
AZZKICKER
09-02-01, 07:58 PM
just get some resistors out and try them where the heat sincer is
instad of the sencer use a resister
start with a 10Kohm or something
keep changing them till there spinning fast..........
That would work if it's a thermister, but I would have thought that disconecting it would have worked as well (simulating infinate resistance or something)
dimmreaper
09-02-01, 08:28 PM
Originally posted by AZZKICKER
just get some resistors out and try them where the heat sincer is
instad of the sencer use a resister
start with a 10Kohm or something
keep changing them till there spinning fast.......... You could also use a rheostat!
Isn't 10Kohm a lot? I have a 10K rheostat, and it is way too strong, I can barely even adjust the fan it is so sensative. Too far one way and the fans stop a little too far the other and she is maxed out. Would a 1Kohm model work better for this? Or should I look for like a 500ohm model. I guess I can't complain though, this rheostat came out of a whole panel of them that a buddy brought home from GM, can you believe they were going to throw 40 of these things away! They all work too.
Inverse to the behavior of a normal resistor, the thermistor resistance goes down as it heats up. Opening the path to the thermistor makes the fan think things are too cool. Try shorting out the thermistor and I bet it'll speed right up.
Hoot
Originally posted by Hoot
Inverse to the behavior of a normal resistor, the thermistor resistance goes down as it heats up. Opening the path to the thermistor makes the fan think things are too cool. Try shorting out the thermistor and I bet it'll speed right up.
Hoot
Ok don't get me wrong here I'm not one of these little kids with my imperical forum knowledge disputing something but I always thought thermisters were made from a super sensative metal whose resistance went up with temperature (like every metal except more sensative)
dimmreaper
09-02-01, 08:41 PM
Originally posted by Coolio
Also is there any way that i can increase that fan's speed by upping the amperage or voltage or something to amke it go beyond 5000 rpm? Yes, get a three terminal 14V preset voltage regulator from the shack(Radio Shack that is), it'll cost like $0.17. Wire it up as dirrected, wire the ground terminal up to your ATX PSUs -5V lead(it will be a wire going to the MoBo), and wire the posative up to your PSUs +12V harddrive lead (the yellow one). Or you can wire the ground lead to the ATX PSUs -12V wire, and the posative up to your PSUs +5V harddrive lead (The red one).
http://www.compute-aid.com/images/atxpin.jpg
The clip on the plug falls between pin 15 and 16.
But be warned, this may greatly reduce the fans life span! And it may overtax the PSUs regulated negative current, causing system stability issues, and possibly PSU damage!
A typical Thermistor curve...
Hoot
my physics tutor would have slammed you for that graph not being labelled properly :)
you gonna have to tell me what the measurements are as I haven't done physics for nearly 2 years
Just a guess... Y-axis is the resistance (in ohms), and X-axis is the temp (farenheit I think)... Am I right? Do I win some kind of special prize?? :D
JigPu
cheers it makes sense now, remember it was 3:39am when I read that and now I'm going to bed :)
You win the kewpie doll Jigpu. Sorry for not cleaning up the labels. It was not my graph.
Hoot
wouldnt you just connect the sensor wire where the black one is?
ArAgOrN
09-03-01, 04:25 AM
Try taking off both the wires to the senser and put the bare wires
together.
i added a resistor, 680 ohms form this little experiment type thing that i bought several years ago. Now it works quite fast but will it work faster if i add anotehr resistor say 10 kohm?
KILLorBE
09-03-01, 01:29 PM
Originally posted by Coolio
i added a resistor, 680 ohms form this little experiment type thing that i bought several years ago. Now it works quite fast but will it work faster if i add anotehr resistor say 10 kohm?
In series or parallel ?
In series NO
Parallel YES
Like Hoot said:Try shorting out the thermistor and I bet it'll speed right up
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