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Topic: Really universal soldering controller (Read 739488 times) previous topic - next topic

Re: Really universal soldering controller

Reply #2895 –
Hi,

now, that is a very interesting thought, and it also seems to be the right place to start looking. Because, the voltage across C10 is 0,7 V, which in my opinion is everything else but close to 0 V. Tracing the problem back to the µC lead me to a broken pulldown resistor for U3 (R21 was bad). Replacing it did not change anything, but ONOFF seems to be having a duty cycle of 50% (at least the voltage of the ONOFF trace is ~1,7 V, measured at U3A:2 and U5:2).

As I am writing this, I reflowed pins U5:2 and U5:3. That solved the temperature problem, indeed. Now, onto the next problem: the lab supply I'm using seems to struggle with providing the required power. It did work in the past, it's specified for up to 8 A, but I guess that's a problem not related to Unisolder but rather something I have to solve on my end. The supply is like 30 years old... Will report back testing with a different supply.

For now I really want to thank you guys for supporting me and leading me to the solution!

Re: Really universal soldering controller

Reply #2896 –
Quote from: kage-chan on
(at least the voltage of the ONOFF trace is ~1,7 V, measured at U3A:2 and U5:2).
It should be logic "0" (at least less than 0.8V ) in cal. mode. That's mean firmware or U5
 

Re: Really universal soldering controller

Reply #2897 –
Hi,

Just a quick update to those interested before I go to bed. I managed to get a few more problems aside, but some still remain.

Quote from: minkok on
It should be logic "0" (at least less than 0.8V ) in cal. mode. That's mean firmware or U5

Yes, that's what I tought. As I said, it was either U5:2 or U5:3, after reflowing it works properly now.

The temperature now rises beyond room temperature, but it is very, I don't know how I should call it... jerky? It jumps around wildly, every now and then a realistic temperature value pops up on the display, but mostly it's rubbish. I've tried to capture it with the software by logging the data through USB, I've attached the screenshots. "Calibration.png" shows the data acquired in calibration mode. Looks very good. "wCartridge.png" shows the data logged during heating. And this is the one making absolutely no sense to me. The ADC value looks perfectly fine. The "Current Temperature", "Filtered Temperature" and "PID Temperature" on the other hand make absolutely no sense to me. How is it possible that they deviate so much from the ADC value's behaviour?

Maybe I will find out something tomorrow...

Re: Really universal soldering controller

Reply #2898 –
In my opinion, you cannot do much, the only thing wasn't checked is a crystal osc.
Did you check Vref, I mentioned earlier?
All the rest is from U5, many ways to fail ( overheated, bad flash, is it china made )
If somebody can give other explanation

Re: Really universal soldering controller

Reply #2899 –
Faulty current temp calculation is the cause of everything else. This temperature is reset if
PV->Starting || PV->NoHeaterCnt || PV->NoSensor || PV->ShortCircuit
First should be false as controller is already started, Noheater and ShortCircuit also should be false as heater resistance just below 3 Ohm is correct and with no flickering, NoSensor also should be false as ADC reading seems to be fine.
Between ADC value and Current Temperature is heavy floating point math happening, probably something's going wrong there.
I tend to agree with minkok for a faulty MCU.

Re: Really universal soldering controller

Reply #2900 –
Hi,

I've done a few additional measurements, this time with a scope. And, by now I actuall tend to agree with both of you. All signals I measured look ok to me, everything points to a faulty MCU. First I did not believe it to be the MCU, because it was brand new, purchased at digikey or farnell (don't remember, but definitily either of the two), so I sure hope it's no chinese copy.
Sadly, I do not have a replacement at hand right now. But, I wanted to order a few things at digikey anyways, so I guess I'll just get another PIC and try to replace it. Will report back to you guys as soon as I have my replacement and soldered it in place.

Again, heaps and heaps of thanks to you guys for bearing with me! I really do appreciate it.

Edit: For completeness sake: Yes, the voltage reference is rock stable at 2,978 V. It is a little less than 3 V, but I guess it's ok. It would only lead to a slight offset in the termperature measurement.

Re: Really universal soldering controller

Reply #2901 –
Hi people,

I purchased the holder in the picture and made me some touch boards as per the instructions on page 96.

The problem I am having is that the touch sensor malfunctions after a short period of working correctly, leaving the sensor permanently closed or open, causing loss of temp regulation, or sensor open message. It seems the nor gate blows.

This only happens when using the quick swap plate, which is connected to the holder plate as per the picture. If I disconnect the link between the quick swap plate and the holder plate everything keeps working as expected, but of course I lose the power disengagement feature when swapping cartridges.

Does this sound familiar to anyone, or am I the only one experiencing this?

Re: Really universal soldering controller

Reply #2902 –
Try to connect plates through a current limiting resistors, 10k should be OK.

Re: Really universal soldering controller

Reply #2903 –
Thanks, will try.

Re: Really universal soldering controller

Reply #2904 –
Quote from: afedorov on
Try to connect plates through a current limiting resistors, 10k should be OK.
Not quite  exactly, 10k - protection up to 100V, I recommend  200k and up, as here, I made it months ago, while I was playing with other stuffs, but have no ordered boards for it,  it will work, if there is no some stupid mistake.

Re: Really universal soldering controller

Reply #2905 –
I have some 820k smd's so I used those. The voltage spikes are suppressed sufficiently now, the nor gate keeps living, but still the screen flashes , showing max temp briefly when I touch the quick swap plate with my hands when I install another tip. This is probably solved by adding a capacitor in series? Any suggestions?

Re: Really universal soldering controller

Reply #2906 –
Quote from: minkok on
Not quite  exactly, 10k - protection up to 100V
Yep, I've calculated it for the usual 90V Cy bias on 230V mains. With 10M pull-up 1M is the maximum value.

Re: Really universal soldering controller

Reply #2907 –
Quote from: minkok on
Not quite  exactly, 10k - protection up to 100V, I recommend  200k and up, as here, I made it months ago, while I was playing with other stuffs, but have no ordered boards for it,  it will work, if there is no some stupid mistake.
Hi Minkok. can you share the Gerber files? JLCPCB can read the attached zip file but it seems it does not read it correctly and is missing the drill holes

Re: Really universal soldering controller

Reply #2908 –
Quote from: Doomedahab on
I have some 820k smd's so I used those. The voltage spikes are suppressed sufficiently now, the nor gate keeps living, but still the screen flashes , showing max temp briefly when I touch the quick swap plate with my hands when I install another tip. This is probably solved by adding a capacitor in series? Any suggestions?
that is really strange. one input ( handle holder) to work correct , the other not, check for a residue of soldering and clean it thoroughly,  do not add any capacitor at ins., remove any tip earthing ( from a main) if you have, replace again the 4001, do you use transformer or sw power supply

Re: Really universal soldering controller

Reply #2909 –
Quote from: Doomedahab on
Hi Minkok. can you share the Gerber files? JLCPCB can read the attached zip file but it seems it does not read it correctly and is missing the drill holes
I used https://www.elecrow.com/ for other project, they can read the gerbers correct, anyway I generated them again with no compression and compressed with 7z