Modding 6 fans into one 3-pin?

[Swatdog]

Its not possible to run different fans at the same RPM on one channel of a rheobus. If you had 6 identical fans this would work.

-CaT

Well, yeah they would be all the same fans. Also, I won't have 6 fans anymore, there will only be 4.

 

[Borisw37]

Swatdog,
The rheobus you linked to, outputs voltage from 0 to 12v, and is rated up to 20watt per channel. It does not use the third wire to monitor the RPM, it doesnt use it for anything. You can connect any number of fans (or any other 12v devices you might want to adjust voltage on) to it, as long as the combined power consumption of all devices on each chanel is below 20watt. I thought you had a rheobus that had RPM readout.

 

[Swatdog]

Swatdog,
The rheobus you linked to, outputs voltage from 0 to 12v, and is rated up to 20watt per channel. It does not use the third wire to monitor the RPM, it doesnt use it for anything. You can connect any number of fans (or any other 12v devices you might want to adjust voltage on) to it, as long as the combined power consumption of all devices on each chanel is below 20watt. I thought you had a rheobus that had RPM readout.

I will... I will also be getting the LIS 2 Premium but the output wattage is only 10W instead of 20W. I wanted the 20W rheobus to control the powerful delta fans that I will be having on my radiator.

 

[hitokiri_808]

I have a vantec fan controller, 18w a channel and it works great for me. Its around $20 at most places. I plan on buying another one for my other comp.

 

[Swatdog]

I have a vantec fan controller, 18w a channel and it works great for me. Its around $20 at most places. I plan on buying another one for my other comp.

Vantec controllers are pretty good, I have a 3.5" not sure of the voltage/wattage.

 

[sevendevilhell]

i've seen fans with a molex connector and then a signal wire coming from it that plugs into a 3-pin and just leaves the other wires open.

if it can't set the RPM while plugged into a molex, then that would be pointless. however, i know that what you're saying is correct. so i'm confused as to why they've made fans with that sort of system. monitoring the RPM does no good if it can't be changed.

 

[zip22]

it is just to monitor. some motherboards require a signal on the heatsink fan plug, and you can also set up things like of a fan stops running, you shut down or an alarm goes off

 

[KillrBuckeye]

i've seen fans with a molex connector and then a signal wire coming from it that plugs into a 3-pin and just leaves the other wires open.

if it can't set the RPM while plugged into a molex, then that would be pointless. however, i know that what you're saying is correct. so i'm confused as to why they've made fans with that sort of system. monitoring the RPM does no good if it can't be changed.

The answer is really quite simple. Think about it, one way or another, the electrical current supplied to the fan is what ultimately determines how fast the fan will spin. If there was a signal wire that could monitor AND control fan speed, there would need to be some integrated variable resistor on the fan itself. This would significantly raise the manufacturing cost of the fan, which is undesirable to the many people (most people) who just run their fans at default (full) speed. Therefore, the fan speed monitoring signal is intended for those who want to manually adjust the current supplied to the fan (via a fan controller) to achieve to desired speed, or for use by software algorithms that dynamically control the supplied current based on case/CPU temperatures.

 

[Ardneh42]

Well I guess I might spend some extra money and get another rheobus... How does this look?

http://www.frozencpu.com/bus-54.html

I have one of these controllers and it is great, but you can find it cheaper at jab-tech.com: http://www.jab-tech.com/catalog/Sunbeam_51_4_Rheobus_Kit__BLACK_p_2530.html

 

[Electron Chaser]

Vantec controllers are pretty good, I have a 3.5" not sure of the voltage/wattage.

They all put out 18 watts per channel.

Just pick one fan to hook the RPM sensor up. It will cause less problems.

If you still intend on hooking up 4 fans to one channel make sure the total wattage does not exceed 18 watts.

What fans exactly are you using? If you could post a pic of them and their connectors and part numbers I should be able to come up with a very viable solution for you.

 

[Swatdog]

They all put out 18 watts per channel.

Just pick one fan to hook the RPM sensor up. It will cause less problems.

If you still intend on hooking up 4 fans to one channel make sure the total wattage does not exceed 18 watts.

What fans exactly are you using? If you could post a pic of them and their connectors and part numbers I should be able to come up with a very viable solution for you.

Well, I haven't bought them yet, but I was thinking about getting these:

http://www.xoxide.com/12alcasfan.html

 

[mtb856]

If you splice all of the fans together into one molex, you'll still be under the max power rating of the Sunbeam (by 2W), so it should handle those fans with no problem. I'm not sure why you need to have an RPM cable attached though, none of my fans on my rheobus have RPM cables and I've had no problem with controlling them. All you're doing is varying the +5V voltage into the card using a variable resistor (or a transistor in more advanced rheobuses like the Sunbeam or the Vantec), RPMs have no effect on how well they work.

Now if you want to monitor the RPM's that's another story, and I'd just do what EC is saying.......... since they'll all be running at the same speed, you only need to keep one of the RPM cables and attach it to the motherboard or something like that. That's what I did with my Delta, I converted it to molex by taking the ground and +5V out of the 3pin and putting them on a molex connector............ then you just leave the blue wire (RPM) in the 3pin and connect it to the motherboard.

Sorry if I missed the idea of what you were trying to say, but that's the way that I understood it.

 

[Electron Chaser]

Well after doing some research since Xoxide's numbers didn't add up add all

.37 Amps *12 = 3 Watts HUH???

I actually found some other specs. .38 Amps * 12 = 4.56 Watts Much more realistic!!

This means the best you are going to get is 4 fans per channel using a sunbeam fan controller and only 3 if you are using a Vantec.

 

[Electron Chaser]

Well after doing some research since Xoxide's numbers didn't add up add all

.37 Amps *12 = 3 Watts HUH???

I actually found some other specs. .38 Amps * 12 = 4.56 Watts Much more realistic!!

This means the best you are going to get is 4 fans per channel using a sunbeam fan controller and 3 maybe 4 (But you are pushing it) if you are using a Vantec.

 

[mtb856]

With the Vantec, you'd be slightly over it's max power per channel with 4 fans so you'd probably end up having to run 3 per channel............ although you have 4 channels on either of those fan controllers, so do you really need to have them all on one channel? Unless you have quite a few powerful case fans, you should be able to fit all of them onto that rheobus with no problems.

 

[zip22]

Well after doing some research since Xoxide's numbers didn't add up add all

.37 Amps *12 = 3 Watts HUH???

i was confused by that myself. gotta love fuzzy numbers in advertising