Voltlog #232 – My New Prefered T12 Soldering Station KSGER V2.1S

Out of the three T12 stations that I have, this is now my favorite and will be the one I use daily. I’m not sure if the performance is higher or similar to the other I have, I’ll probably do a separate video to compare them but it’s just the user interface, the menu options, the nice handle that make me wanna use this instead of the others. Yes it has a few disadvantages regarding this handle, it does get warm and it doesn’t really fit that well with a regular stand but I can go past those disadvantages for how nice this station is. If you’re looking for a T12 station this is definitely the one to get.

I also did a second video where I showed the problems I found with this soldering station and if they can be fixed by the user or not.


24 thoughts on “Voltlog #232 – My New Prefered T12 Soldering Station KSGER V2.1S”

  1. Hi, thanks for the review.

    Can you please explain a bit more about the earth connection? Is the soldering tip earthed? Is the negative DC output connected to mains earth as well?

    Also, in my controller, two of the five wires that go to the iron are connected together. Is is the same in your version?

    1. Soldering tip is connected to earth together with negative dc output. Ideally you would have a resistor in line but that’s not how they wired it.

  2. I see, thanks. So, non floating output.

    What about the DIN connector? Are all 5 pins independent? In my version, two of the pins are connected together (they are connected via the pcb).

        1. BC1 (BC1Z if it’s not too cramped an ara, it has a thicker neck but same tip), and JS02.

          The BC1 tips will give you almost the same size tippy-tip as an I type, but it’s cut at 45 degree angle, so you can adjust the angle holding the tip and lay down the “cross-section” if you need a bit more tip surface area to the board/pad/component. The J-tips J02 and JS02 (I prefer the latter) are good for drag soldering , breaking up multipin chip solder bridges, “reaching around” components etc. Avoid the JL02 though. If you intend to use the actual tip. Because of its construction and mass, the extra diatance from the heater element to the very tip, the solder pools and sticks to the hottest area on the tip which is in the elbow of the tip. Because it’s so long, that’s a far bit from the end point of the tip.

          The real kings of drag soldering are the BCM (BCM1, BCM2 etc) tips. They are like the normal BC ones but have an indent in the tip that will hold and grab a small pool of solder. They cost a bit extra though, not too bad a price jump if you’re already buying genuine tips, but if buying the knockoffs the gap is big – buying 4+ tips at a time you usually get the good knockoffs for 3-4 dollar each, but the BCM tips are speciality so those knockoffs cost easily 8-11 dollar a pop.

  3. KSGER Controller H/W Ver2.1S has a few design flaws. The battery goes dead quickly due to R10. The cold junction compensation using the handle NTC does not work for me, it has no effect on the displayed temperature in the bottom right corner.
    The power supply has HV traces going right under heatsinks which have mounting pins close to the secondary side.
    Add a safety ground to the enclosure. A wire from the IEC ground to somewhere on the enclosure. Otherwise, the encoder/knob is not grounded and ESD can damage it.
    I wish these reviews thoroughly tested the features.
    The extra vacuum desoldering pump parts, I have the board schematic.

  4. Hi, I saw your updated review video.

    I also have the 2.1S controller (same like yours) which has the battery draining problem. In fact my kit came without a battery at all. My psu is different though. It the one with the 2 input filtering caps and the 3 output caps. It’s quite common psu, for these T12 kits.

    Lastly, I don’t understand why you said that the iron tip should be connected to the protected earth through a resistor and not directly. See this thread in eevblog and especially the comments from member “floobydust”: https://www.eevblog.com/forum/reviews/how-to-get-rid-of-fluctuating-voltage-on-soldering-tip-(t12-clone-station)/?PHPSESSID=47shmqq7iufn2cdi5huek5end5

    1. Some of the viewers suggested you wouldn’t want a high energy discharge path through your soldering iron tip and that made sense, that’s why I recommended having the 1M resistor. But if you look at it from the other way, it’s true with a 1M resistor, a voltage could build-up on the tip with a bad powers supply. I do not know what the safety standards say on this but it might vary depending on whether you have a metal or plastic enclosure.

  5. Can you check if cold junction temperature is working on your station S/W 2.10; My temp reading does not change at all, regardless of NTC thermistor voltage.
    Menu 04. Cold End is the calibration for it.
    Changing to Cold End->MCU seems to work, the reading will change if I put finger on MCU as teh temp. sensor.
    But the handle NTC does nothing and I verified the A/D input does see correct NTC voltage.
    I will post the H/W 2.1S schematic on eevblog tommorrow, along with the 24V PSU.

    1. But why should the temp reading change at all? the purpose of the control loop is for the temp to not change. So any change in the cold end will be internally compensated.

  6. There’s two temperatures measured- tip and cold junction. Each has separate calibration.
    Cold junction temperature is measured by the thermistor in the handle, or you can select the MCU’s temperature sensor in menu 04. CJC is supposed to correct for the thermal EMF’s in connections as you transition to copper.
    Somebody thought being close to the heater socket was best for accuracy.
    The number you dial-in menu 04 is just calibration of the thermistor. But S/W 2.10 seems to (wrongly) only use this number as the temperature. I saw your video 31C and it read 31C and it should have climbed up as the handle gets warmer.
    The “N” (NTC) terminal you can change the voltage or NTC resistance and see what happens. For me, nothing changes 0V, 3.3V, 1.7V all read whatever is set in menu 04. It’s supposed to be measuring that temperature.
    KSGER store is very difficult to communicate with. They asked for a video. How do you talk to them?

    1. Ok, now I understand. In my previous comment I thought you were referring to the tip temperature display changing because of CJC and it wasn’t making sense to me but I now realize you we’re referring to the CJC thermistor temp display.

      I’ve just checked and my station does measure NTC value from the handle and the value displayed is updating as the handle is slowly warming up. It is accurate too, no problems with my unit.

      As you will notice from the links in my video description I did not get this from the official KSGER store but from a different store so I don’t know how KSGER communication is like.

  7. T12 STM32 2.1S controller schematic:

  8. sorry URL missing a “/” at the end.

    T12 STM32 2.1S controller schematic:


    Thank you for checking your CJ temp. I saw the value move in your review, but 1 degree is due to wiring voltage drops when the heater is on, so I wasn’t sure.
    If I warm my handle or change A/D MCU pin 17 there is no change in the value. I will experiment then just request a return from KSGER store.

    1. It’s not just 1 degree, it will vary according to the temperature, for example if I start at 25C it will normally go up to 32 degrees after using it for a while.

  9. Followup, I got a replacement V2.1S controller S/W 2.10 and cold-junction temperature works. My first controller is defective and stuck reading whatever you set on menu 04 i.e always shows 24°C.
    The new one, with handle unplugged, displays !24°C (value from menu 04) but reads a temperature when the handle is plugged in.
    I’m not sure which thermistor is supposed to be in the handle (glass MF58 10k or mystery black bead).

  10. Hi!
    I just bought a ksger v 2.1s controller.Is there a problem if I install a 24v 6 amper power supply?
    Thank you!

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