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FEATURED Building PWM Controller for 4 wires PWM fan

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Brutal ...finally.... congratulation ! :clap: :rock:

Thanks for sharing that video ! :thup:

Now you know why I was sorta insisting you do it on breadboarding 1st, think about it, if you did it at PCB level, and having troubles like these, trust me, it will be very2 tiresome and worry with all the mess at the soldering & desoldering to fix them, sometimes this kind of stuff will turned into abandoned project. Again, happy to hear its working well ! :thup:

Now you've seen its working, this will greatly motivate you to do the PCB version without any hesitation.

Please, take few shots at that breadboard at various angles and post them here, those pics will provide as a good ground reference to others that might jump in to build one too.

Now, put that Sanyo Denki and shoot the video of that beast at lowest rpm up to it's max ! :D



EDIT :

From that video, it looks like you were turning that pot counter clock wise to speed it up isn't it ? If that is the case, just swap the connections of the two outmost pins from that potentiometer to make it behave the other way around.


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I think this is my final draft before I go into PCB Production. :)

DSCN0583.JPG


DSCN0584.JPG


P.S. I will swap the Poti around when I put it on the board.
 
Ok, first try was a fail. :(

Wasn't really equipped with the right tools and the Proto board I was using was kinda small.

So I went and picked up a solder pump, some different color wire (multi colors) to make it easier to see the circuits, and a better proto board that has circuits more like the bread board. Also picked up a smaller guage of solder (OMG its expensive). Going to see if I can find a smaller tip for my iron. Its kind of chubby for the tiny connections.

I probably could have hunted down a prefab circuit for a lot less than it takes in tools, but it is like that with everything. Total project cost so far is about $150 dollars. :(

I guess once I have perfected the method I can probably sell some of these. :)
 
Hows that circuit working on your Sanyo Denki mini beast ?

Curious at the speed when you dial down that pot to minimum, since this PWM generator does not go down beyond 2% duty cycle that will make it fully stop rotating.

If you're not happy with the 2% minium and want full sweep starting from perfect 0% (zero percent) pure flat line up to full 100%, I could give you the other circuit, but this one needs 3 ICs, which are 2 555 and one additional IC called comparator.
 
I didn't hook up my Beast to yet. I tried to put my circuit on a board last night. It didn't go well. I think I keep trying to make it too small. So I went out and got the stuff I needed to do the job right. I bought thinner solder (that stuff is expensive) but my friend at work says, it will last me forever, so its more or less a good investment. I got a solder sucker, some flux (I forgot about this the last time) and a project board that looks almost like a breadboard, but a little smaller. I got some more components so I don't have to tear down my mistake board. I will get it done, but I see taking these steps slowly both teaches me new tricks and is more successful.

This is after all my first circuit that isn't on some pre-fab RadioShack board or kids project board. And its more than just a lightbulb, switch and battery.
 
Ok, I finished my circuit and transfered it to my prototype board. I works on my Xigmatek fan. It does not turn the fan completely off. If I had to guess, its maybe at about 10%.

The problem is I used this on my San Ace and it does not change the fan speed at all. To double check, I grounded the PWM wire and the Fan turns off, when I apply 5V it goes to full speed. I then hooked it back up to my Xigmatek fan and it changes the speed. I hooked the San Ace back to my motherboard, and it varies the speed.

Not sure what happened with the math, but I was pretty sad after all this time I spent on the circuit. These are my circuit board pics.

DSCN0588.JPG


DSCN0589.JPG


DSCN0590.JPG


DSCN0591.JPG


DSCN0592.JPG


This is my controller working on my Xigmatek.

Youtube link of San Ace being tested. I grounded the PWM circuit, then applied 5V to show that the San ace was working properly.
 
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OK, I just had a chance to check the circuit on an O-scope. It is in fact a square wave. However it is an old Oscilloscope.

While checking we noticed that the base of the wave rises and falls as well as the top of the wave while adjusting with the potentiometer. I am still confused why this does not work on my San Ace.

Any ideas?

Edit:

Ok we took out the good Tekstronix scope (He forgot they had gotten this a couple of months ago, but it has never been taken out of the case). OMG it made a difference. Also noticed that I can't use two seperate grounds for the fan and this circuit. In order for it to run right, the circuit ground and the fan ground need to be the same. Hopefully that has an effect on the San Ace, I will post when I get home. I also have a video of the Circuit on the O-Scope, that I will put up when I get home.
 
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You're right, this PWM controller's ground and the fan's ground must be on the same rail.

Did you you use separate PSU ? I thought you're powering this controller and the fan from the single PSU ?






.
 
It was a single PSU, but not the same Ground wire. I was using a 4 Wire. Two grounds and a 12V and a 5V. I hooked one up Ground-5V and the other Ground-12 V. When you look at this set up on the Oscilloscope, there is too much noise. So maybe that was the problem.

Here is the video of my circuit on the oscilloscope.
PWM Oscilloscope Video

I hope it looks right, and that you have enjoyed my thread. I have pulled out a few hairs doing this, and this would have been a lot cheaper if someone had just sold me one. :) If this is right, I am going to box it up, mount the Potentiometer ( actually I am gonna see if the potentiometer in my sunbeam is 3 legged and 100KOhms, if so I am going to hook it up there on one of those channels.) and then I should be set.
 
It was a single PSU, but not the same Ground wire. I was using a 4 Wire. Two grounds and a 12V and a 5V. I hooked one up Ground-5V and the other Ground-12 V. When you look at this set up on the Oscilloscope, there is too much noise. So maybe that was the problem.

Here is the video of my circuit on the oscilloscope.
PWM Oscilloscope Video

I hope it looks right, and that you have enjoyed my thread. I have pulled out a few hairs doing this, and this would have been a lot cheaper if someone had just sold me one. :) If this is right, I am going to box it up, mount the Potentiometer ( actually I am gonna see if the potentiometer in my sunbeam is 3 legged and 100KOhms, if so I am going to hook it up there on one of those channels.) and then I should be set.

Awesome ! What a nice scope you got there ! :thup:

Now, from that video, it shows that the circuit is working, at least it is oscillating, also its clear that the duty cycle changed as you turned that pot, great ! :thup:

About the noise, if the margin of that noise level is only few percent compared to the overall pulse height, its fine, that is normal. In fact that is the realistic view of signals in the real world, and its almost impossible to see a really smooth line unless that circuit and the scope are lab grade and in tight controlled environment.

Since you got your self a nice scope there, if you had a chance, please measure the pulse height, it must be around 4.7 to 4.9 volts, close to 5 volts, while at the pulse width at one cycle (one up + one down), it should be around 40 us and this equal to around 25 Khz.

Remember, measure it while it is connected to the fan and running.

View attachment 82541
 
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Ok, didn't have a fan here at the time. As for the voltage, yes... it is at 5v.

The signal looked really noisey before when I was using the old scope. The newer one cleans it up alot. I think it was just the old scope.

Do you think the reason the fan wasn't working was because I didn't have them hooked up to the same ground? And why was the other fan working? What difference would this make while hooked up to the fan and running?
 
Ok, didn't have a fan here at the time. As for the voltage, yes... it is at 5v.

Now, that could be the problem, to measure it correctly, it must be connected so it will show if the fan is not drawing the PWM signal too far, ideally is should be around 4.7 to 4.9 volt when loaded with fan. That 5 volt shows it is not loaded at all, so that will not show the problem if the fan is sucking that pwm signal too far.

Suggesting you bring that beast and the controller at the scope to view it, that will be easy to see the problem if any.

The signal looked really noisey before when I was using the old scope. The newer one cleans it up alot. I think it was just the old scope.

Do you think the reason the fan wasn't working was because I didn't have them hooked up to the same ground? And why was the other fan working? What difference would this make while hooked up to the fan and running?

Could be, just make sure the ground is using the same rail, having the same ground will like standing at the same firm floor (ground) between the controller and the fan, so the fan will see the incoming pulse signal steady at 0 and 5 volt since they're sharing the same negative (hence that is why its called ground). ;)

If both have different ground, then the pulse that the fan is receiving could be possible garbled, since they're not standing at the same ground level, hope this analogy will help to clear things out.
 
Aye, that makes sense. I really hope this is the problem though.

In your opinion, the circuit seems sound as do the O-scope readings? In theory, this should be working?
 
Ok, after plugging it in with common ground, the problem still persists. This works on my xigmatek fan, but not on my San Ace.

This got me thinking. The Fan is not plugged into a common ground in my case. Pos.+12 and Neg to the Power Supply and PWM/RPM to motherboard and the fan works fine. I know the PSU has a common ground for all components, so I assumed the same would be with the power supply outside of the case.

Now I am sad. I have dropped a lot of time and money into this and it doesn't work on my San Ace. Please help.
 
Brutal, do you have any more 555 IC ? Understand that you don't have any scope at home.

I suspect that Sanyo Denki is sucking too much power from the PWM out from that controller.

If you have that spare 555, this is an emergency circuit to boost that PWM power and easily can be built in minutes at your breadboard.

View attachment 82549

This an inverted schmitt buffer, but with stronger output power compared the one from the Nidec. One small thing to remember, it will invert the signal, so before this if you turn clock wise to speed up the rpm, with this circuit that clock wise will turn the speed down.

No big deal, just swap that pot's two outer most legs to make normal again. ;)
 
So just add this to the existing PWM circuit I just built? Looks easy enough.

Yep, just connect the PWM OUT from the circuit you built to the PWM IN, and use the PWM OUT from this new circuit.

Just see it as a signal amplifier to boost the power output.

Btw, do you have unused stock Intel HSF ? You can try it too just to see if its working right as well apart from the Xigmatek fan.
 
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