View Full Version : To buy or not to buy... a fan controller.

11-04-2004, 09:42 PM
I have 5 fans, and I am getting 3 more.

I want to monitor them all, and my motherboard can handle 3 of them... so I want to buy a fan controller. My question is, which one? I don't mind if I can only monitor 4 fans, but atleast four.... and it better have an LCD screen!

So if you have any suggestions, please do say so!

Jen C
12-04-2004, 10:19 AM
In the March issue of NZ PCWorld there was an article on cooling cases. They used a heat sensor and fan montior/controller called DigiDoc5 for their test machine. This is the device here (http://www.dragonpc.co.nz/images/case/dd5/dd5.htm).

There are also a variety of fan controllers listed at the OCNZ shop here (http://www.overclockers.co.nz/product/casemod/controller/ocnz.shtml) and here (http://www.overclockers.co.nz/product/casemod/controller/cm.shtml) which should give you some idea what is available.

12-04-2004, 12:52 PM
The digidoc5 works OK, but has no hysteresis in the setting.

That means the fan is constantly on/off/on/off when the temperature set point is reached. Annoying at worst, but the reporting (via the LCD) on fans, temps and current is good, and much more accurate than the motherboard sensors.

12-04-2004, 01:16 PM
Ok i was thining stylish and cool looking like the Thermaltake HardCano 12, but then that's just because my ego depends on it, and it looks good.

The digidoc5 looks good... minimalistic looks but hey...

(I'll add the hardcano to my wish list...)

So tell me more about this hysteresis thing, So the fans keep switching on and off.....

12-04-2004, 01:19 PM
oh yeah, I know the hardcano 12 is for HardDrives.. but i thought i could just plug fans in anyway... or not... well I guess it's out of the picture...

So hysteresis...

12-04-2004, 01:32 PM

Say you set it to turn the fan (s) on when the temp on that channel reaches 40 degrees.

At 40 degrees exactly the fan turns on. That immediately lowers the temp half a degree, so a couple of seconds after it turns on, it turns off as the temp is 39.5 degrees.

Then the temp immediately rises to 40 again and it turns on... and so on.

Hysteresis would mean that it would have a "dead band" after it turned on at 40, so unless the temperature dropped to (say) 35 or so it would not turn off so quickly. Without hysteresis its cycling every few seconds.

12-04-2004, 03:06 PM
aaaahhhh... cheers...

But that dont worry me, I'll leave em all on, all the time.

12-04-2004, 07:31 PM
> aaaahhhh... cheers...
> But that dont worry me, I'll leave em all on, all the
> time.

I have the DigDoc and its quite good, apart from the issue that GF raised (which is quite noticeable if you've got it turned on). Beware there are 2 (maybe more) kinds - one handles 8 fans and sensors, the other handles 4... the one that handles 4 still looks for 8, it just has 4 plugs.


12-04-2004, 08:59 PM
oK so how serious is this hysteresis issue? I mean if i left them all on and didnt set a turn on temperature, would it affect me ? :-S Can i overcome it in some way?

And how much is it? I sent dragonpc an email, but they havent replied. I can't find any other retailers...

12-04-2004, 09:07 PM
> oK so how serious is this hysteresis issue? I mean if
> i left them all on and didnt set a turn on
> temperature, would it affect me ?

If your fans are always on, it'll never concern you. It only happens if you've set the fans to turn on at a certain temperature as GF explained in his post.

Its not a major problem, nothing really to be worried about. It just means that if they're set to turn on at a certain temp, when you hit that them the fans concerned could be constantly turning on and off every 30 seconds or so. It may be a noise problem, and it may also reduce the life of your fans. Other than that, its just whether it annoys you or not.


Andrew B
12-04-2004, 09:39 PM
Maybe I have missed something here, but if you are going to leave all the fans running all the time, why do you need an fan controller? What is it going to control?

12-04-2004, 10:04 PM
Well i'd like to monitor all the fans, or maybe get em to speed up and down. I never thought I'd slap a fan in to not use it. I also want to monitor lots of temperatures, which, i may add, these fan controllers do. So what i really need is an lcd screen - but i'll buy a Fan controller, they're cooler.


12-04-2004, 10:12 PM
The Digidoc5 does not control fan speed, just OFF and ON.

Terry Porritt
13-04-2004, 08:15 AM
The other thing you can do with simple on/off control systems is to add some lag (hysteresis if you like as godfather said), this can be electrical or mechanical. For simple temperature controllers, if you dont mind less precise control of a set temperature, is to increase the thermal mass of the temperature sensor, so that it takes longer to respond in either warming or cooling.
Put the sensor inside a small block of metal for example.

13-04-2004, 08:55 AM
hmm just get yourself a thermaltake case mmmm, just got me a 1000D, nice case with 7 fans and two temp monitors and 4 controllers :)

Run slow and quiet when not doing much and then crank them when playing games

14-04-2004, 10:17 AM
this digidoc5 is appearing less and less appealing...