FW modification is required. Theoretically, only SChannel parameter of NO INSTRUMENT profile have to be changed to 2, but I didn't tried it. Both current source channels are set to 128, so calibration resistor can go to either. If you have some problems with ch. B ADC value would be close to its limits.
Thank you for the SChannel hint, I couldn't find any documentation of that parameter in the source code, it would have taken me a lot longer to figure out. Thanks!
And, senseB seems to be perfectly fine. When I change only the SChannel parameter to 2 and connect the 10 Ohm resistor between vout1- and senseB I get ADC values of around 999-1002 (exactly the same as with senseA). When I additionally change the heater channel to 1 and connect the resistor between vout2- and senseB I get 993-995. So an acceptable deviation. But, that in my eyes also shows, that the wiring is definitely ok, right?
Any other ideas what might be wrong?
I just noticed that my EARTH wire is not connected anywhere yet, it's floating. Wanted to connect it to PE later, when the PCBs are in an enclosure. I'm powering the PCBs with a DC lab supply at around 15 V. Might that be an issue? Just wondering...
It's because C210 TC is connected differently within cartridge. With C245, temp sensing is using both diff. amp. channels with ch. B going below GND, while calibration is done using ch. A only, probably the problem is with ch. B, i.e. U16 and surroundings. Is -0.6V rail OK? Having the ability to switch between channels in calibration mode will ease the input section troubleshooting.
Thank you for the clarification regarding the C210. I also do suspect channel B being not ok. U16 is more or less brand new. I replaced U16 before. Shortly after that, I realised that I had D21 and C64 shorted (GND pin of D21 to high side of C64). That should have protected the BCH input of U16 from any damags I guess. How can I test if it is ok or not? I do not have a replacement at hand. The -0.6V rail is at -0.67V, I guess that's ok? Is there a way in the supplied FW to calibrate Ch B?
that's correct for the molex, about mess with Vout2, if you have correct ID and the Fuse 5A wasn't burned still everything is ok, to be sure check R64 and D21 use 10 Ohm R when measure the input chain ( to have your hardware safe, the time you measure and your hands free ). Read and compare from page 190
D21 and R64 seem to be ok, as written above, there was a short, but it is fixed now. For channel A the values match up. Is there a way to do the same for channel B, without rewriting the FW?
I know I am a bit late to start asking questions, but I am really stuck on the last issue. I started building the station like a year or more ago and did not finish it. Now, I wanted to finish it once for all. I am using a JBC T245 handle on the station with a C245 cartridge.
I have read most of the posts in this thread, there also were a few other people with the same issue, but either they didn't post their solution or their solution does not apply to me.
Issue: When I power up the station with handle and cartridge connected, the cartridge heats up, the displayed temperatur is stuck at room temperature. But, aperiodically the displayed temperature jumps up to like 40 or 60 degrees, but still far from the actual tip temperature (after 3 seconds the tip temperature should be well beyond 40°C or 60°C I guess...)
What I have tried so far:
Calibrating works without an issue.
I have double an triple checked my wiring. I cannot seem to find a mistake or problem. Just as an additional information, I have no idea if it matters: vout2+ and vout2- were mixed up before, but they should be correct now. Looking from the top on the Molex connector for the iron power: top left: vout1-, bottom left: vout1+, top right: vout2-, bottom right: vout2+. Could anyone please confirm this?
When in calibration mode and the tip + cartridge are connected, I do see an adc value. For room temperature it is barely above 0 (single digit), if I heat the tip up with a different soldering iron the value will rise. So I guess the TC in the cartridge is ok.
Its hard to tell, but when measuring the voltage at U16A:2, it seems to not rise above 153 mV. As I said, I'm not 100%ly sure about this one, because it's hard to measure only with two hands and an heating element running wild... I have not tried replacing D20 and C63. Maybe I should? But, I also assume that the 153 mV are due to the heating, and not due to the TC.
When powered down, Q2, Q8, Q10 and Q11 seem to be ok (few MOhms between D and S)
Obviously, tool detection works properly, if no cartridge is inserted into the tool, I get a "HEATER OPEN" message. The tool is correctly shown as JBC C245
I have not tried reversing the TC polarity on the connector. But, I also haven't found the reason sparkybg gave why it should not be connected the other way round, like for the C210. Can anyone point me to a answer there?
Any help is welcome to solve the issue, I am stuck for days now, this seems to be really the last issue I am having, I am out of ideas right now.
I am able to compile the FW, so if you want me to change things there to try something I could do that.