Fan hub to fan controller overwattage?

George0107

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Oct 28, 2013
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I'm going to buy two of these NZXT grid fan hubs:

http://www.amazon.com/gp/product/B00D2ZK2VW/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

and also this fan controller:

http://www.amazon.com/gp/product/B00K0VKEUK/ref=ox_sc_act_title_7?ie=UTF8&psc=1&smid=A1S9W9A986D3KF


Besides 1 channel using around 59 watts, two other channels are going to use around 25 watts each.

What i'm wondering is, if I turn the dial on the channel that uses 25 watts all the way up, does it send 60 watts to the fan hub? Or does it only send the required watts(this case 25).
I'm wondering because the fan hub can only take 30 watts, and if anymore, it would burn it out.

Any help thanks?
 
Solution
The controller only feeds the power required(the dial changes the voltage, the fan/number of fans determines the actual wattage required.). It is good for upto 60 watts per channel(this is mostly due to its switching design and higher efficiency). After that it will either shut down or fail(I am guessing shut down or fold over in some other way).

Now the GRID will just split the connectors so multiple fans can be connected. When the fans are turned down, the leds on the GRID may dim, but it should not hurt anything. It is a very basic design.

It should go without saying that the GRID will not pass speed information for all fans.
The controller only feeds the power required(the dial changes the voltage, the fan/number of fans determines the actual wattage required.). It is good for upto 60 watts per channel(this is mostly due to its switching design and higher efficiency). After that it will either shut down or fail(I am guessing shut down or fold over in some other way).

Now the GRID will just split the connectors so multiple fans can be connected. When the fans are turned down, the leds on the GRID may dim, but it should not hurt anything. It is a very basic design.

It should go without saying that the GRID will not pass speed information for all fans.
 
Solution

George0107

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Oct 28, 2013
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Thank you nukemaster. To clarify is channel 1 wanted 25 watts, the dial would go from 0 - 25. If it happened to be 45 watts the dial would go from 0 - 45, and etc?

Also if you happen to know, what would need to be added to the fan hub to make it go from a max 30 watts to 60 watts? A capacitor? I don't know much about electronics, just want to know for knowledge reasons.

EDIT for nukemaster response:
I asked a guy who had 30.4 watts per fan, had 2 attached, had it for a couple of years, said it was fine. But I'll try to find a fan with lower wattage so it comes around 55 watts or 50.
 
I am not sure if all fans will draw power in an even/linear way. The controllers are a voltage device. So with the dial all the way down the controller will feed the fans 0-1.5 volts(not enough to run). As the dial is turned up the voltage will increase(most fans start to turn at about 5 volts.). The fans will draw power depending on the voltage the get.

OHMS law states that wattage = voltage^2(squared) / resistance(now not all loads are the same at various voltages. so this is VERY simplified)

Lets say you have a 12 volt fan that requires 12 watts or 1 amp. That fan appears as a 12 ohm load(you will not always have such nice numbers to work with).

Lets plug in the numbers.

@ 5 volts
Wattage = 5^2(voltage squared)/12(ohms)
2.083 watts. down from the 12 watts at 12 volts.

Again, not all devices work this way. This is not a perfect world and a fan is NOT a resistor. I have house fans that take only 20 watts less at low compared to med/high(and these are fans that max out at 80-100 watts) making high the most efficient way to run them.

Truth be told, I am not sure how NZXT rates these devices because it is simply a splitter on a board. ALL the fans are just paralleled to one another. As long as the traces on the board and the wire connecting it to the power supply can handle the load, if should not be an issue.

Please note while 60 watts seems like very little power, at 12 volts it is 5 amps.
5 amps @ 120 volts is 600 watts. It needs a wire size that can handle 5 amps. Current is why you use larger wire more than voltage for the "low" voltages we are dealing with here.

Now onto increasing the power handling of the device. Bigger wire and larger trances are how you increase a power rating of a splitter. This is the same reason a appliance extension cord uses larger wire than one for Christmas lights.

Capacitors are good for smoothing power and when combined with inductors in switching power supplies can help provide very clean power(thus the rather large coils/caps on that controller). They can also be used to block DC in audio circuits and with resistors can perform a similar filtering to the cap/coil assembly(at a cost of some voltage). With a different configuration the same parts can be used to filter audio(remove bass for speakers that can not handle it/filter out high frequency noises/ect)