PWM to Analog converter circuit

No that doesn't sound right. The b772 is not a to-220 so maybe that's where confusion is coming from. The pinout needs the emitter being provided with the 12v.

Send me a trust message and I will send you a proper schematic.
 
I just wanted to thank Tealc for all the excellent info.

I have been drawn to this PWM to DC topic lately for two reasons: Phanteks own hub can develop overheating derived problems if used below 20% PWM, and I currently using it at 3%. Also, I bouhgt a Gelid Icy Vision for my wife without knowing it doesn't does PWM.

I know nothing about electronics, it is one topic I always wanted to have some time to learn and -unfortunately- I think I will have a lot of free time really soon, so having a project and good info like the one on this topic to focus on will help me a lot on my learning.

So, thanks again :)
 
@Tealc: Do you still offering to build these? I needed one to control my 3pin cpu cooler on my mb which is a 4 pins pwm.

Can you PM me? As new user, it seems i cant.
 
Just found this thread after a quick google, shame your not making them anymore as I'd have been interested for sure and your only round the corner.

The phanteks pwm hub is 'end of life' I'm told so they don't seem to be an option anymore :/
 
I may be up and running again in a little bit as I'm planning to get a shed/workshop to go out the back. I may even have a semi complete naked board in a box at my Mums that might even be close to fully working. I can't remember but did spot one as I was looking for a IR receiver the other day and doubt I would have kept it around if it were fully incomplete or faulty. I tended to build them 2 or 3 ahead of 'orders' and added heatshrink to complete.

I quite enjoyed making them so will do some again, I just haven't pushed it because Phanteks were doing theirs, although by reading some posts they were not without issues.
 
Last edited:
Just been down to my Mums and I seem to have two boards that have OK written on them. One is a molex powered unit with 4 fan and the other is a standard fan to 3 fan unit.
 
I tested it as best I can using my PC and my CPU fan and it still works as expected. I had to crank the potentiometer right down as my CPU fan is a super low current Noctua NF-P12.

I'd normally have 2 or 3 fans and load it up to one of my oscilloscopes rather than faffing about with my PC but my scopes are in storage.

I don't have any heatshrink here so will have to grab some from my stocks, unless you want it naked and fancy wrapping some tape around it or something.
 
I'm not fussy, pretty sure I'd have some big enough heatshrink kicking around my works van somewhere :)

Will only be running 3 fans on it with space for another when I add my front rad in the future. Assume that will be ok with a little tweaking on the pot.

Drop me a trust with how to pay etc if you would :D
 
That Zalman is a different thing. I've never seen, tested or bothered to read much about them but it may be a controller that outputs a 5v variable duty cycle that'll control attached fans. I have made one of these and used it to test my own circuit. I built it out of a 555 timer ic and a few passive parts, simple enough.

Now if you wanted 8 3 pin fans controlled of my converter circuit then it would need to be two individual standard circuits. I was developing a high power circuit but haven't got a workshop at the moment so never got that completed. Phanteks sort of came along with their non adjustable version and orders for mine dried up.

I could still possibly make some circuits though. I quite enjoy throwing circuits together.
 
Tealc said:
That Zalman is a different thing. I've never seen, tested or bothered to read much about them but it may be a controller that outputs a 5v variable duty cycle that'll control attached fans. I have made one of these and used it to test my own circuit. I built it out of a 555 timer ic and a few passive parts, simple enough.

Now if you wanted 8 3 pin fans controlled of my converter circuit then it would need to be two individual standard circuits. I was developing a high power circuit but haven't got a workshop at the moment so never got that completed. Phanteks sort of came along with their non adjustable version and orders for mine dried up.

I could still possibly make some circuits though. I quite enjoy throwing circuits together.
Click to expand...

Just sent you a trust :)
 
This sort of thing.

2vj9ct0.jpg


Schematic shamelessly copied from the internet.

The 555 timer basically uses the 100k potentiometer to adjust the duty cycle from one side to the other. It's what I based my own PWM controller on, although I trimmed it to get near 22kHz frequency.

The thing is I don't actually have all the parts and test gear I need at home. I would need to go and get them all from my Mum's house, which would take a while.

The potentiometer can be wired so it is remote from the PCB itself but I'm not sure if it could quite reach a desk without picking up all kinds of stray signals that could piggyback themselves on the PWM wave and cause problems. This is something I'd need a scope for to be sure.

Are you sure there isn't a commercial option for something like this? The Zalman thingy could be easily modified I would expect just to get the variable PWM from it. Edit: Scrub that as it looks like you can't get them any longer.

If I was building such a device I'd like it to have a low threshold, say 30% duty cycle which would need designing in and it would be ideal if the circuit also threw the fans into 100% duty cycle for a short time on power start, just to make sure the fans get started.

Edit: Looks like you can pick up a decent range of PWM controllers off ebay for not too many £s. Such as this one Not home made but cheap and would easily handle 8 fans. It has a decent frequency. The fans would be driven as if they were 3 pin fans, which makes sense. You'd lose tach feedback of course.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom