Open source universal soldering station controller

Arhi posted v3 of an open source soldering station controller. Add an AC transformer from a cheap soldering station and you have a powerful pro-tool. Settings are entered by a rotary encoder dial, temperature and menu options are shown on a 16×2 LCD.

It works with most major soldering iron brands. Hakko (thermistor) or Solomon (K-type thermocouple) soldering pencils can be selected with jumpers. Replacement iron/handle assemblies are actually quote affordable (<$20), even quality stuff like Hakko.

Project files are available in the forum. A USB-upgradable version is also in development.

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  1. marvin, there’s not much sense in a digital control of a rework fan as temperature decrease with square of the distance .. moving your fan closer or farther from the pcb makes more changes in temperature then any control you have on the fan controller. Mine rework station don’t even have temperature settings but temperature levels 1 to 8 and air speed levels 1 to 8 – no relation between C and level as if it is 400C on the tip of the nozzle temperature 5cm from the tip varies from sooooooo many factors (room temp, room air movement speed, size of the nozzle, speed of the air trough nozzle etc etc etc ..) for any temperature values to make sense … digitizing it would not make it any better… no would actually make any sense .. analog control works perfectly there :D

    1. I just thought about it because I’m making a project that involves a lot of smd components and some chips that exist only in LGA/QFN/QFP packages. So, obviously, I need a rework fan in addition to my usual soldering iron. The iron+fan stations are a little bit expensive for me now and I’ve found a shop that sells repair components for soldering stations. They have a quite good fan for 20$ while the station that uses this fan costs about 80$. So I’ve thought – “Oh, could I make a controller for this fan? I already have a soldering iron that satisfies me, so why I should replace it with a station? Making a controller for the fan would definitely be cheaper”

      1. well, looking at fan I have, you could control temperature identically as you do it for soldering iron, same sensor, same heater .. here, the only problem is how to control air flow, on mine I have a compressor with a tank and air valve that’s controlled directly trough pot (just 2 op amps between pot and valve, you could in theory use mechanical valve too not much difference)

  2. The fan I’m planning to use has a kind of turbine mounted directly into it’s body, so it connects to the station only with several wires – motor, termocouple and heater. I suppose that heater could be controlled with a symistor (TRIAC) and the motor could be controlled with PWM-driven transistor. Feeding the termocouple output to ADC of ATmega will result in a thermal feedback and temperature stabilisation

  3. What is different with the T15? Do you have a theory of operation for the difference? or a pin out description of the T15?

    1. difference is that they don’t use separate 2 wires for the sensor and 2 wires for the heater but they operate trough 3 wires. my controller does not support 3wire setup.

      if you search the forum you will find the pinout for the 3wire connector for T15 along with some cutout pictures of the tip under microscope

    1. no I’m not working on new driver and I don’t think it makes sense really to do it. soldering stations are cheap enough and good enough. I invested lot of time making SID not in order to make “next best soldering iron” but to find out some things about soldering irons and what I came to realize is that “precise” temperature is irrelevant in 99% of the time. What you can benefit from is a good tip design, heater and sensor as close to tip as possible, good thermal mass of the tip and that’s it .. tips with cartridges can do this .. JBC tips do this excellently, hakko tips don’t really do this as good .. in any way I got me some professional stations (pace and weller) to compare with some cheap clones, with my hakko driver, with my weller / solomon driver .. and it’s all same crap .. today you can get a cheap hakko (with old tips not the T12/T15 ones) for 25$ .. and it works great .. what’s the point of making your own .. the T15 station cost around 100$, how cheap your free time must be to build your own .. I did it ’cause I wanted to know if it can be improved – and yes, it can, problem is the improvement does not really mater while soldering, it changes nothing .. you don’t get nicer solder joints, fancier soldering styles etc .. it works the same .. 10C here and there really makes no difference ..

  4. Thanks for your input. I don’t want to make a “new” solder controller, I have to since I am trying to control 20 T15 tips from one robot system controller. I could get 20 hakko fx-951 controllers and have the operator set 20 different temp settings manually, but in production, this is not feasible. I just need to know how the temp signal gets out of the T-15 so that I can have a simple PID controller that is addressable from the system software and thus control each tip’s temperature set point.

    Thanks for your input.

    1. yup I understand your problem :D . check out the thread I linked, you will find there both the pinout and the sample driver (not made by me), no idea how good it works but you will get pinout that should be enough to get you started

  5. Sorry Im a pain. I still cant find it. When I take out the spaces, the web page comes back with a cant find response.

    http : // dangerousprototypes . com / forum/viewtopic.php?f=56&t=5264

    1. do you have account on the forum?

      click on forum, go to Board index / In development / Project logs
      find theme named “My HAKKO classic and T12/T15 soldering controller”

  6. @Kent – The link is in the first sentence, directly under the picture near the top of this page.

  7. Ah yes, I see now. Your short link work fine for me once the two spaces are taken out of it.

  8. Thank you for your help. I finally got the link to work. I am now just going to try and hardwire into the FX-951 controller. I should be able to pick up the temperature read back and route it to my robot controller as an analogue signal. I then should be able to send pulses from the robot controller to the FX-915 push buttons, to set the desired temperature. This will get me going for now. Do you know of any schematic for the FX-915 control board? Thanks

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