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DIY Fan Controller for PWM Fans

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So, the PWM controller is done, and works great.

It's butt ugly, but it works great.

Here it is, sealed up with some hot glue, just so nothing shifts around and causes a short:

28930893273_6eb6c70025_b.jpg

I ordered a 3 pack of extra drive bay covers from corsair so I could chop one up and install switches and the pot with a dial on it to control my fans.

29263885430_bb1872e9bf_b.jpg


Middle switch: Fans On/Off
Right Switch: Fans Manual control or auto control based on water temp (if middle switch is on)
Dial: Controls fan speed via PWM

29553832825_c5a752cffc_b.jpg


Turns out the front panel on Corsairs Obsidian series bay covers is textured sheet metal. It is glued somehow to the plastic part of the bay cover underneath. I pried the metal part off using a contractor knife. The goo from the glue was intense. Took lots of goo-off to clean both sides. Then I carefully drilled/dremeled holes to fit my two switches and my pot dial in the metal front, and went nuts with my dremel on the plastic to make everything fit in the back.

I was going to glue them back together again, but I think the screws that tighten the switches and pot to the panel do the job, so it's not needed.

The hole locations weren't exactly perfect. I measured them precisely, but kept slipping with the damned drill when I went to drill them. Should have used a punch to start the holes, but I couldn't find mine. I don't think I can tell that they are misaligned, but if it winds up bothering me, I have three more spare Corsair drive covers to re-do it on. :p

I wiped the damned thing down, but it appears to be statically charged, and clings to all the dist from my dremeling. Will have to do a more careful cleaning when I put it all together.

If anyone is curious, this is what the final result looks like once installed in the case. (I really should have wiped down the front better before taking this picture, and maybe I shouldn't have been lazy and used my DSLR instead of my cell phone :p )

Click for larger:
28996008663_40476338a3.jpg

I'm by no means a seasoned case modder, but I am happy with how it turned out. It's not perfect, but neat enough, and it definitely works as intended.
 
Thank you very much for your How-To! It is awesome! I build it myself and have a problem now. I'm a... well can't really say "noob" but not so well educated in the electronic circuits-area.
I can only controll the top 10% (I think) of the speed range of my fan. It is a Arctic F12 PWM PST.
I am not using this fan for my PC, instead I'm using it to create an (small) airflow in my room to prevent mold.
Currently I use the dual 555-Timer solution but there is no difference in the control in comparison with the one 555-Timer-Circuit.

Breadboard-PWM.png

This is my Circuit. Hopefully labled everything important (those Diodes are standard 1N4148)
Is there a way to increase the range? Or am I doing something wrong? Suggestions?
Thank you in advance!

(Sorry if I upset somebody with my spelling and grammar. Not a native english-speaker)
 
Thank you very much for your How-To! It is awesome! I build it myself and have a problem now. I'm a... well can't really say "noob" but not so well educated in the electronic circuits-area.
I can only controll the top 10% (I think) of the speed range of my fan. It is a Arctic F12 PWM PST.
I am not using this fan for my PC, instead I'm using it to create an (small) airflow in my room to prevent mold.
Currently I use the dual 555-Timer solution but there is no difference in the control in comparison with the one 555-Timer-Circuit.

View attachment 183286

This is my Circuit. Hopefully labled everything important (those Diodes are standard 1N4148)
Is there a way to increase the range? Or am I doing something wrong? Suggestions?
Thank you in advance!

(Sorry if I upset somebody with my spelling and grammar. Not a native english-speaker)

Your English is better than some people here in the USA :)
It looks like you got everything but a little hard to tell in that rats nest of wires :rofl: Try a different fan and see if it does the same thing, if that don't work, check then recheck and check again then check again :) to make sure the connections are in the right place, even techs can get a wire misplaced now and again :rofl:

I like your breadboard, take a look at mine:
DSCN0562.JPG
 
Final drawing:

556PCB2.jpg

SMT & Through Hole combo:

556TH.jpg

The SMT parts have the "a" in the ref number, C4 is for through hole ceramic cap (yes they make 10uf ceramic caps), C4b is for electrolytic cap.
 
Last edited:
I did 3 rebuilds, nothing changed. Tried it with my PC-CPU Fan, nothing changed.
Is it because I'm using an 555NE and not a 555 CMOS?
 
I did 3 rebuilds, nothing changed. Tried it with my PC-CPU Fan, nothing changed.
Is it because I'm using an 555NE and not a 555 CMOS?

The 555NE and 555 CMOS is the same thing. Recheck all the connections and the parts, if any part is the wrong part it won't work right. I say this because I've had to recheck and found a wire in wrong place or wrong part. Also from your picture, it looks like the cathode of both diodes are connected, it could be from the angle the pic was taken.
 
Hi folks,

I`m new here and was already reading a couple of hours about building 555 PWM fan controllers at the forum. Very interesting, just what I searched for!:thup:

As I don`t need to drive high-power fans, I decided that I`ll go for this more simple circuit (single 555 PWM controller):
http://www.overclockers.com/forums/...for-PWM-Fans?p=7677647&viewfull=1#post7677647

However, I´d like to add a Kick-Start feature as in the more complicated (advanced?) dual 555 (556) circuits... but I`m not quite sure if I can just hook up the Kick-Start-Add-On part (outlined in blue) from here:

http://www.overclockers.com/forums/...ires-PWM-fan?p=6931080&viewfull=1#post6931080

.....to Pin-4 (RESET) of the 555 schematic from the first link above in order to accomplish that?

Another question: it appears to me that I can simply substitude transistor Q2 in that Add-On with a single diode (1N4148 etc.).
Is that correct?

Any help would be greatly appreciated.
 
I didn't see this answer anywhere but I might have just missed it..

Anyways what did this all set you back. I know I can grab a 4 channel fan controller for about 15 bucks.. So while this DIY project is definately cool, trying to see if the time/material investment is worth it over just buying a retail one. I am guessing the retail fan controllers are much more cheap in a time investment/material cost stand point, but I have been wrong before.
 
I didn't see this answer anywhere but I might have just missed it..

Anyways what did this all set you back. I know I can grab a 4 channel fan controller for about 15 bucks.. So while this DIY project is definately cool, trying to see if the time/material investment is worth it over just buying a retail one. I am guessing the retail fan controllers are much more cheap in a time investment/material cost stand point, but I have been wrong before.

DIY is not about cheap, it`s all about being able tailoring stuff exactly to ones needs. Yes, that`s very cool.
Retail mostly simply don`t cut it (besides this, it`s often either crap or overpriced... or both).
 
Hey Guys sorry for the major bump here but This circuit looks perfect to allow me to use PWM on a Fan in my PS3. However I am having issues with one thing. The picture of the Circuit on Tagboard below doesn't show the track cuts that are needed to be made.
I am still learning on how to transfer circuits from a diagram to a tagboard and this part always gets me. Can anyone help me out locate what tracks on the tagboard need to be cut?


pwm-stripboard-with-components.png


PWM-circuit.png
 
Here is the layout for the back but I could not stand how sloppy it looked,

trackbreaks-300x225.jpg

So I had these made and I put the parts on, it's the same circuit as what is on the stripboard.

DSCN0598.JPG
DSCN0595.JPG
 
Inclusion of LED Indicator

It will be nice if we include a LED indicator in this circuit.

Please advise how can we include a LED indicator in 556 Dual Timer Circuit with Kick-starting feature
 
It will be nice if we include a LED indicator in this circuit.

Please advise how can we include a LED indicator in 556 Dual Timer Circuit with Kick-starting feature

A LED indicator as in a power indicator or something else? If it's for power indicator, take led and 300 ohm resistor and connect from 5V to ground. Other than that I'm not sure what your asking.
 
IC 555 Circuit gives around 16KHz frequency

Tried the single 555 IC circuit on simulator. It gives around 16Khz frequency square wave.

So this circuit can not be used for the fans which need around 25Khz PWM controlling signal.
 
Tried the single 555 IC circuit on simulator. It gives around 16Khz frequency square wave.

So this circuit can not be used for the fans which need around 25Khz PWM controlling signal.

Build it for real and see if it is 16KHZ or 25KHZ. And are you sure your using the right parts in the right places in the simulator?
 
Build it for real and see if it is 16KHZ or 25KHZ. And are you sure your using the right parts in the right places in the simulator?

Yes, Placement is correct. I replaced C2 with 470pF. Now circuit is giving 25KHz output. Use C2=680pF for 16KHz O/P frequency. Use C2=470pF for 25KHz O/P frequency.

sim.png
 
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