Adding an RPM sensor to a fan?

MikeHunt79 · 12 Oct 2006 at 23:42

Ok, this will be for a shuttle sn45g

The motherboard has 3 fan connectors on board, and the nice thing is, when a fan is plugged into the motherboard that has an RPM sensor, the motherboard can control the speed of the fan.

Now, if have an arctic cooling VGA silencer on my 9800 pro,which has a speed switch for the fan, high and low. Very crude. Now, if I could somehow add an RPM sensor to this fan, my shuttle could then control the speed, and it would have more than 2 levels. If this possible? i can easily cut and solder wires, but anything more and i'm not really sure what i'm doing.

Hades · 13 Oct 2006 at 00:13

Probably easier to just replace the whole fan with one which already has the 3 pin motherboard connector?

mosfet · 13 Oct 2006 at 00:16

If the motherboard has the capacity to moderate fan voltages then it shouldn't need an RPM voltage input to do that, have you searched for 3rd party fan controller software?

If you really need a fan with an RPM sensor line, buy a new fan. Much easier, cheaper and quicker.

MikeHunt79 · 13 Oct 2006 at 01:10

I would buy a new fan if I could, but the VGA silencer uses a strange fan that you can't buy seperately... I'll try plugging it up to the motherboard and see if I can control the speed, but if it doesn't work, I guess I'll have to remember to flick the switch to change the speed.

EDIT: I'm using speedfan to control my fans, it works well for my 2 case fans already connected.

Hades · 13 Oct 2006 at 01:20

Just googled for a pic of the AC and I see what you mean by the fan. It's built into the shroud so would be hard to replace unless you split it the new one of of the fan casing.

From memory though the AC uses a small two pin fan header - this won't fit a motherboard three pin fan header. But you can get 2pin to 3pin adapters. As mentioned above you don't need to monitor the RPM to control the speed - and a 2pin to 3pin adapter still won't provide RPM monitoring. But it should allow you to control the speed either on a fan controller or on the motherboard using Speedfan.

But if I recall, my old 9800 Pro with AC was silent even on fast :confused:

MikeHunt79 · 13 Oct 2006 at 03:29

It is possible to open the cooler up by taking the screws out the shroud. I guess I'll try the adaptor or maybe just solder up the wires to a 3 pin plug I've got lying around somewhere. On high you can definately hear it tho, but I think that might be because the rest of the shuttle is pretty quiet.

I still need to do some chopping up of the lid, because the cooler sticks out the case. :eek: