Fan RPM Sensor / DigiDoc5 Question

[Ricam78]

This is probably a newbie question, but I searched and I coudlnt find anything.

Here goes, I have a DigiDoc5 installed and setup and I plan on getting some new fans for my case that have a seperate connector to connect the fan to a 4 pin power supply and then the RPM sensor (yellow) goes to a 3 pin molex. What I am wondering is if I hook the 3 pin molex yellow only cale from that fan to the digidoc, will the digidoc be able to control that fans speed (raise it when the CPU reaches a certain temp) or does the DigiDoc need to be the power source for that fan in order to control the RPMs...if this doesnt make sense let me know and I will try to clear it up.

Also, the DigDoc I have has been modded somewhat so that 4 of the extension cables for the fans have a 4 pin connector on one end and that goes the the normal 3pin molex. What I want to know is is there fans sold that have the speed sensor (yellow cable) that goes into a four pin connector? Again let me know if this is confusing.

Any help will be greatly appreciated.

Thanks,
Rich

 

[Bluefront]

You're right....it is confusing. If you want the DigitatDoc5 to control a fan ( turn it off/on by the temp setting), you must hook the fan directly to the D/D, not to the molex computer connectors. If you do hook it to a computer connection, the fan will run all the time, and the D/D won't do anything for you, no matter where you plug the sensor wire.

You can hook up all the eight temp sensors without using any fans....in that case you will be able to monitor eight different temps...but no fan control. Right now mine is set up like that, but I am controling one small extra cpu fan that turns on at 40C. I love the thing....still figuring out different uses for it.

Your final question? Explain it again.....

 

[Ricam78]

Thanks for the response, it helped a lot. Just another quick question though....the digidoc should read the RPM of the fan if just the yellow wire is plugged into the back with the 3 pin molex right?

As for my second question, the guy I got this from modded the extensions so that 4 of them looked like this

What I want to know is are there fans that have a 4 pin connector like this nad if so where do I get them. I have seen the 4 pin connectors with the red and black, but never the yellow.

Thanks Again,
Rich

 

[Bluefront]

heh...never saw a connector like that.

The D/D really does not measure rpms. It only shows a spinning fan icon when one of it's attached fans is running, only letting you know if the fan is running....not the exact rpm.

 

[Ricam78]

Oh yea....well thanks again for the response. I guess I will have to just get some more 3 pin extensions then since I am using all tha I have now and I need more. The guy I got this from modded i think 5 or those extensions so that they had a 4 pin connector. Know of a good place to get those extensions. I found somewhere where they are a buck but I would have to have an order Min of 10 dollars.

Thanks Again for the Help

 

[BongoDave]

I have a question about the DigiDoc 5... i'm planing to get one soon but i'm wondering if the D/D can controle the fan speed, not only on/off (2000 RPM, 5000RPM). Thanx

 

[OulOat]

Uhh... that looks very bad. Very bad indeed. The yellow wire from the PSU and the yellow wire on the 3 pin are very different things. The yellow wire on the 3 pin convery the RPM signal. The yellow wire from the PSU is the 12V line. If you try to plug that into the fan you'll probably end up frying the fan, maybe even your psu. The red wire from the fan goes into the yellow wire of the PSU and black goes to the black. Hm, however, if this is a custom job, he might have fiddled around with the wire layout. I would still get a multimeter to measure the voltages on each pin so you don't end up with fried fans.

4 pin molexs are used for PSU connections. Because the PSU can't monitor fan speed, there is no RPM sensoring wire. The standard way to get speed monitoring from a 4 pin molex is to use this. Hm, it's strange why the guy modded it, as you can see here the digidoc has plenty of 3 pin connectors, which is what is standardly used for fans.

 

[Ricam78]

Originally posted by: BongoDave
I have a question about the DigiDoc 5... i'm planing to get one soon but i'm wondering if the D/D can controle the fan speed, not only on/off (2000 RPM, 5000RPM). Thanx

Good question and thats something I was trying to figure out when I made my original post.

As for why the gyuy did the mods, I dunno. He converted the 3pn to 3pins to the ones I showed a pic of. Oh well I am looking online now to find some longer 18 - 24 inch extenders...but still no luck.

 

[Ricam78]

Oh and another thing since we are talking about molex connectors and fans...are there any quiet modelrately good flowing BLE LED fans with a Molex connector?