Designing a PWM to Analog mini board for fans
-
@fcwilt said in Designing a PWM to Analog mini board for fans:
You asked for a PM but I don't know what that is.
PM = personal message, so just chat
/Julien
-
First batch ordered!
15 PCB are on its way
If there is no problem with the design, I'll order about 50 more, wich would be enough for all the boards everyone asked for.
Anyone wants to betatest a board from this first batch once arrives?
-
@Egon-Net said in Designing a PWM to Analog mini board for fans:
Anyone wants to betatest a board from this first batch once arrives?
-
@Egon-Net said in Designing a PWM to Analog mini board for fans:
Anyone wants to betatest a board from this first batch once arrives?
Be happy to.
Frederick
-
@Egon-Net Iām in for beta testing if you need. We are also pretty close geographically
-
Boards arrived!
They are VERY small and very cute
As soon as I get some spare time I will assemble the first one and perform some testing. If it all works ok, then I will move it to the betatesters phase -
@Egon-Net, looks very nice, with good clearance for the mounting posts.
-
Ok, here it is! First board mounted!
I have to recognize the accuracy of TINA TI simulation. It warned me about an inestability, but I wasn't sure if it was a simulation error or the real thing. Turned out it was the real thing, TINA TI even nailed the shape of the inestability checked with a real oscilloscope on the real circuit. Luckily, I already found that a capacitor fixed the inestability in TINA TI, and it worked too in real life:
It's a shame that such a cute board needs something that cluncky , but hey, that's what betatesting is for.
The good news is the circuit works very well, the output is very smooth, and roge fans work perfectly. PWM selector also works as expected, allowing active high/active low/open collector PWM. And although the opamp is supposed to work from 4.5V, I tested it as low as 3.3V and it still worked ok! And the output beautifully tracks Vin on the fly.
The response from PWM changing is as fast as "I can't measure it visually" (about 0.3 sec according to the simulation) .
So from now on, time to request betatest units, knowing they will need that extra capacitor. I have components to build 10 boards, and 14 bare pcb's.
Regarding cost, this is what I thought:
Just a bare board: 4ā¬/piece
DIY kit (without headers/jumpers): 8ā¬/kit
Fully assembled and tested (with optional headers/jumpers): 15ā¬/piece
( + shipping costs).@ZipZap , @marcelorider , @fcwilt still interested in betatesting?
Once betatesting is completed, I'll modify the board with only SMD diode and a new smaller SMD capacitor, so the board will be a little bigger but cute again.
Comments?
-
Some oscilloscope captures, all at 250Hz, 4V PWM, 12V Vin.
(Apologies for my function generator, is quite rubbish)99% PWM (oscilloscope can't detect duty cicle reliably)
75% PWM
50% PWM
25% PWM
1%PWM
-
Sounds all swell to me.
I'm still in on beta-testing, i would like an assembled board (because of a missing hotair-gun...).
For the final version, i would like eight (8) non-assembled kits. -
Hey, happy to see it is working fine
I'm in for the beta testing, shot you a PM, let me know something as soon as you can to get my hands on it.You also need to include or build info regarding the jumpers to make it easier for people like myself
-
To all betatesters: How is it going? Any comments yet?
-
Still testing, should be ready tomorrow or wednesday.
-
Bummer.
I have another circuit (@Egon-Net for the big fan), which should have a ripple around 30mV.
It shows me a ripple of 28V... i think my oscilloscope is not working right.I have a replacement in delivery, so i should be able to make all my desired measurements around the weekend. Sorry for the delay.
/Julien
-
Well, I just mounted 8 PWM beta boards in my printer, two for each tool (one cold end, one part cooling)
I already connected 4 of them, and they work beautifully. I finally can control my stubborn fans! I'll make some more endurance test (to check temperatures in the long run) and wait for the betatesters to report, but there should be no problem for a final board run.
Still interested?
-
Everything ready for the next batch of final boards!
Everyone who asked me for boards is already contacted for this batch. There are 23 boards finally requested, so I'll probably do a 25-board batch. Does anyone else need one before I place the orders to part suppliers?
I can also supply a STL/STEP file with the board and a basic box just in case you need
-
@egon-net Out of interest. What would the cost be per board, delivered to the UK? Do you think they could be assembled with a fine tipped soldering iron, or only hot air?
-
@nexxcat said in Designing a PWM to Analog mini board for fans:
@egon-net Out of interest. What would the cost be per board, delivered to the UK? Do you think they could be assembled with a fine tipped soldering iron, or only hot air?
Regarding cost, this is what I thought:
- Just a bare board: 4ā¬/piece
- DIY kit (without headers/jumpers): 8ā¬/kit
- Fully assembled and tested (with optional headers/jumpers): 15ā¬/piece
- Shipping costs to UK: 5ā¬
Regarding building the board with a fine soldering iron... It could be done since every part has its legs exposed and parts are not that small (SOIC8 & 0805 SMD), but it would be much more difficult.
-
@egon-net Thanks
I'll hold off for now then, but great work on the product! -
This is the new board:
It's a bit bigger so now the capacitor is included and the diode and the led are in top side. Also a bit more of space surrounding the in/out connectors.
BTW, I think it's the last board I make with Ultiboard. I have tested Kicad and its support for footprints is way better (I can directly import them from Mouser!)
