Powerful DIY JBC Soldering Station - 250W C470 Arduino-based

while working on assemblies I felt like my trusty 80 watt fella wasn't up to the task for the first time these boards were made with thermal performance in mind so some especially the ground pins can take huge amounts of heat away from the place where you need it of course you could try to compensate by increasing your soldiering iron temperature but then you'd risk overheating your semiconductors to better solutions are a high thermal capacity soldering tool or a more powerful heater that can react quickly and to replenish the heat after the ground claim has taken its share so I was browsing through these sexy JBC stations for the other day drooling just a little bit but geez those prices are realtor knows all the magic actually happens in the tips which they call cartridges heater and thermocouple are built into those so isn't the handle is just a comfortable socket basically those two components are quite affordable actually even with brawny 250 watts I think I'll buy those and try to DIY the power supply station the materials for which are already here I'm sure about that wow I didn't expect the JBC components that quickly whoops that's something else entirely sorry of my fault but here they are for real t 470 Henry field fantastic and one of the C 470 cartridges business and ready for action now for the command center theoretically very easy we've got a heater and the temperature sensor built into the cartridge all we need to add is a sufficient power supply and a PID temperature controller that controls the power going into the tip in such a way that it heats up quickly but doesn't overshoot in practice there's a little difficulty built into JBC cartridges the little difficulty for DIY endeavors at least for everything else it's a sophisticated solution with many advantages essentially it is a heater and a thermocouple in series with a center tab that way the heat occurence doesn't have to pass with a thermocouple as it does in certain hako tools I think and the thermocouple materials can be selected freely instead of incorporating the heating wire only a few disadvantages for me to deal with for example we have to cut the power every time we want to take a measurement the temperature reading would be influenced otherwise because thermocouple and heater share a pinned let's get started with a couple of tests if possible I'd like to use an integrated max three one eight five five code junction compensated thermocouple to digital converter it has everything built-in and it delivers the temperature ready to use over the SPI bus I'll hook it up between an Arduino and the soldiering iron and I use my most trustworthy thermocouples as references good news first I can power the heater and leave the thermocouple converter connected because it doesn't overload and it recovers instantly instantly there we go on the other hand the readings aren't equal and only proportional below 100 degree C so I think it's safe to say that the JBC thermocouple is not a type K and needs rescaling in software if we go along with us all in one chip solution there's another problem if I wanted to ground a tip which I think I do the thermocouple converter would report an error I could try to set up a floating ground for the control circuitry to circumvent the problem but I think I'll investigate the alternatives first apparently an off-the-shelf PID temperature controller could also handle it but I couldn't live with a clicking relay and the missing power control Haho and so humongous overshoot doing it all discreetly feels a bit redundant because Sparky BG has already published an incredible project in the dangerous prototypes forum please check it out it leaves no wish unfulfilled except maybe in terms of complexity it's a huge project worth every second you put into it but here's my minimalistic approach using a 24 volt DC power supply and the MOSFET high side switch works fine but can never unleash the full 250 watts of power I had falsely assumed that the big cartridges would be content with 24 volts but the heater resistance is actually 7.2 ohms and to deliver our peak power through there we need something above 40 volts well I don't have a DC power supply with that voltage it is not any usable size nope but I do have this hi-fi amplifiers and forma and that looks like a perfect fit and AC power controller can be done very gracefully in an application like this but I'm getting ahead of ourselves let's get the basics sorted first we need an instrumentation amplifier to measure the minuscule thermocouple voltage I'll use an LTC 2051 which can easily be configured as one as a matter of fact the typical application is an instrumentation amplifier with a gain of 101 perfect I'll copy that it's a bit noisy and not particularly accurate but it's plenty good for soldiering temperature which is usually chosen in 20 or even 50 degree C steps the same applies to a temperature sensing arduino the simple semester based voltage divider is sufficient for cold Junction compensation then we can connect the soldiering iron to the instrumentation amplifier and the instrumentation amplifier to another microcontroller ADC I thought about grounding the tip with a 1 Meg resistor in case I ever touch a live conductor accidentally but the internal resistances are much lower so I think higher voltages would find a way through no matter what the main power switch is a triac in this first attempt gets really warm though and should be replaced with something efficient ASAP my first inclination was to do face cutting for proper AC power controller but I found multiple disadvantages for example audible humming from those sharp corners so for now I'm passing full waves only which is elegant simple and overall the right approach in my opinion in those pauses I'm taking the temperature measurements yeah you better shake off those drops idiot perturbations when I'm far below the target temperature I want few measuring pauses so that I can reach the setpoint as quickly as possible thirty two three hundred and ten seconds that's more like the performance I expected even a Tesla couldn't beat that when I'm close to or at the set temperature I can take measuring pauses all the time to avoid overshoot and react quickly to sudden changes let's see how that looks in software the millivolt variable is initialized to the current thermocouple voltage in millivolt taking into account the gain of the instrumentation amplifier and that voltage is multiplied by forty three point five which seems to be a good approximation to get an uncompensated thermocouple temperature reading to which I add the ambient temperature to compensate it totally stole that number from Sparkie BG anyway that gives us a plausible temperature output on the serial cord to get the best performance I'm using a bit of low-level AVR timer magic if I didn't have a zero crossing interrupt I could just turn off the triac gate and wait for one main cycle before I take a measurement the difference in performance wouldn't even be noticeable I guess but it's just neat how this way isn't it and here's what I talked about earlier the closer I get to the target temperature the more often I take measurements if a measurement is an order I turn off the triac gate wait for two more main cycles to make sure everything is settled down and take the measurement as before if we are missing eat and turning on the triac otherwise not that's it but it's probably a bit much to take in all at once so I'll put a link to the final software in the description it should have buttons and LCD support to I could go on and on with this video about PCB design about dropping phones in ferric chloride and about mediocre edging results because of debilitating frustration I would have loved to address gopro hero4 retail packaging in particular but the point of this video was how easily you can get superior jbc performance on a budget I think I'll keep my superior JBC performance permanently so I'll finish the project to the best of my abilities without having to reach around a camera all the time if you're interested in the final result you should consider subscribing because it will surely appear in my future videos thanks

Channel: Marco Reps

Views: 272,087

Keywords: weller, soldering, jbc, thermal, mass, performance, heat, iron, temperature, capacity, heater, 250w, station, tips, cartridges, handle, t470, c470, power, supply, thermocouple, controller, pid, phase, cutting, diy, hakko, arduino, interrupt, timer, maxim, max31855, overload, ac, instrumentation, type k, amplifier, avr, c245, c210, mosfet, high side, switch, 24v, dc, 40v, hifi, transformer, thyristor, triac, linear, ltc2051, gain, operational, op amp, adc, thermistor, bt138, humming, wave, zero, crossing, mains

Id: GYIiOkr6x9o

Length: 11min 8sec (668 seconds)

Published: Sun Jan 15 2017