How can I mod "Nexus" fan controller, so it goes from 0 to Full Blast?

How can I mod "Nexus" fan controller, so it goes from 0 to Full Blast?
Mine goes from like half way to full blast.

Turn fan speed knob to full to get full blash, unplug the POS if you want 0. See, that wasn't so hard.

i dont think many go to 0, because this could cause damage to components. youd have to replace a lot of the parts, and pretty much start from scratch i think. i dont know much about how that controlled works though

Most big fans don't run at even 5 volts, let alone start up on power-on. 6 volts is the safest IMO, but some big fans recommend 8-13 volts for operation. They don't change the voltage internally to get a certain RPM at 12 volts, it has to do with increasing/reducing the 'winds' (wire) on the armatures (thats what they're called in, umm, non-brushless motors).

When you run a 12 volt fan below 5 volts, it stops, but its still using energy. That energy is basicly frying your fan's electronics, if not all at once. The following solution may/may not work, since I haven't delt with diodes before. If you ran a ~6 volt Zener diode between the power regilator and the fan, it would let all voltages above 6 volts pass to the fan, but cut the power below 6 volts. Zener diodes are usually used as a surge bypass (normally open connection), and I don't know if they'd heat up or take the prolonged periods of normally closed operation.


Other than that, you'd need new 10k ohm pots that have an off switch on the low-ohm side (hard to find, if they even make them), get a new IC and redesign the whole circut, or rig a switch rated for at least 3 amps/14 volts/20 watts and put it between the power regulator and it's respective fan output. You'd have to manually switch it off, but its the easiest in my opinion.



Based partly on how lots of Nexus's have fan channels die as well as how my Nexus has a minimum of at least 7.7v (too high for me), as well as how it whines at low voltages - I'm actually going to gut my Nexus and make a few LM317 circuits. I'll even one for the LEDs, since the Nexus IC controls them too. I'll be in complete control of the voltages, and they are known to be reliable. I can also swap in a LM350 and get a 3 amp channel - enough for even 2-4 big deltas.

you need belt driven fans

ok thanks. didnt really wanted 0 but a little lower speed than the lowest. i have a 92 tornado.

hmm, this is interesting. the Nexus 305 I have turns the fans off completely at its lowest setting... which one do you have?

5.25

How about a Tornado tamer for a $1.65 + shipping..

RHEO LINK

INSTALL GUIDE

t1mex said:

hmm, this is interesting. the Nexus 305 I have turns the fans off completely at its lowest setting... which one do you have?

Click to expand...

Mines the black nxp-205 3.5" model. I'm gutting it anyways...$15 for knobs, alum. facia and 4 pots. Vantec products aren't bad, but they always leave something to be desired. The good thing is that w/the new circuits, I'll be able to turn down/off the LEDs too. My controller doesn't hum at low volts, maybe because its minimum is 2+ volts higher than others? I can't test the voltage due to the pulsing power, but I know the fan is quiter on a measured steady 7.5 volts (haven't modded my antec to fit yet, POS psu) than on the Vantec's lowest setting, which is a claimed 7 volts. I've had 3 others in my house verify that its louder, so its not my imagination.

I'm kinda in the same position.
I have the 3.5" Nexus controller, and have attached 6x 80mms spread across 3 knobs and the last one has a 80mm Tornado attached.
The Tornado is always turned down the lowest it will go, which is 3500 RPM. But it's still to loud for my liking. When turned up full it reaches 5500 RPM. I wish i could turn it down more than 3500 RPM. I've done the 5v and 7v mods, but I prefer having it connected to the controller. If only it wasn't so loud...

Try the 92mm Panaflo U1BO Voodoo....www.digikey.com Item # P11044-ND...68.80 cfm @ 43 dBA/ 3450 rpm..full tilt..I forget, are you running a 80mm or 92mm on your SLK-900U ?

Ha ha, I said in the last post, its an 80mm arch.

The sunbeam fanbus lets you goto 0 volt.

Crappers, I'm a blind man.. Have you tried a 92mm on that HS yet?

Yah my Nexus 305 completely shuts the fans off when dialed down. Im always worried my kids are gonna mess with it and fry my system heh.