UniSolder - The universal soldering controller

Control almost any low voltage soldering instrument

My intention was to build the most universal soldering controller I can think of. It can drive any low voltage (upto 24V) iron with thermocouple or resistive sensor, in series with the heater, or separate.

A short list of features:

• power: 12-24V, AC or DC (24V 6A toroidal transformer is the best possible power source)
• automatic 1/2, 1/4 and 1/8 power selection, so only simple single winding 24V transformer can drive all the instruments, from the smallest JBC Nano, to the largest JBC C245.
• 2 separate heater control channels
• 2 independent sensor inputs
• current source on any sensor input 3uA - 12mA, with 2 bands (x1, x16) and 256 steps per band
• flexible differential amplifier input selection
• amplifier gain from 0 to 750 in 256 steps
• negative offset selection in 1024 steps
• resistive instrument identification (upto 625 different instruments can be identified by 2 resistors in the connector)
• polynomial floating point voltage/resistance to temperature calculation
• wave shaping to filter out the inductive peaks from series sensor signal
• PID control with power limit
• isolated USB port for firmware updates and live data
• 128x64 OLED display with rich user interface.

Tested so far with:

• HAKKO T12/T15 (series TC)
• HAKKO FX8801 (PTC)
• PACE TD100 (series TC, the controller also uses the cold junction sensor in the iron's handle)
• PACE TD200 (series TC, the controller also uses the cold junction sensor in the iron's handle)
• JBC C245 (series or separate TC, depends on connection)
• JBC C210 (series TC)
• JBC Microtweezers (PA120/AN120, 2 separate heaters, each with series TC)
• JBC C105/C115 (series TC)
• JBC Nanotweezers (NP115/AN115/NP105/NP105-B, 2 separate heaters, each with series TC)
• WELLER WSP80 (PTC) (This iron was sent to me by a reader of the thread for a previous version of the controller. Thanks, Jaroslaw)
• WELLER WMRT (2 separate heaters, each with separate TC)
• ERSA RT80 (series PTC/heater resistance)
• various chinese cheap irons with separate TC

Some movies:

• JBC C245: https://www.youtube.com/watch?v=oTdQB4ywDOA&feature=youtu.be
• JBC C210: https://www.youtube.com/watch?v=iyz-EDf-JaY&feature=youtu.be
• T12, JBC C210, JBC Microtweezers: https://www.youtube.com/watch?v=-f0KSU0PJzc&t=70s
• Chinese T12: https://www.youtube.com/watch?v=u588sh-4thg&feature=youtu.be
• Weller WSP80: https://www.youtube.com/watch?v=gd_8w7l8_Bo&feature=youtu.be
• Weller WMRT: https://www.youtube.com/watch?v=eHNJuQEw6XU&feature=youtu.be

Additional resources

• Valerio made a great git repo with plenty ot usefull information and notes here: https://github.com/valerionew/unisolder-notes
• There are really big thread for this project, where this all started: http://dangerousprototypes.com/forum/index.php?topic=7218.0

The calibration procedure

• Connect a resistor with well known resistance (0.1%) of around 10ohm between SENSEA and Vout1-
• Go to "CALIBRATION" submenu
• Adjust the calibration trimmer until you get value of "R" as close as possible to the resistance of the resistor, multiplied by 100 (1000 for 10ohm resistor).
• Optionally, press and hold center button for 3+ seconds an release it - the "currect" parameter should now show "1 128" instead of "0 128" it was showing so far
• Connect the same resistor to SENSEB and Vout1-. The Value of "R" should be da same or very close to value shown 2 steps above. If there is a significant difference, there is a problem either with current sources or 0.1% resistors they must be made with.

My connection layout and the calibration connection in real world:

Connections to different tips/irons:

1. HAKKO T12:

• Outer shell, and heater negative (middle) terminal connected together to Vout1- and EARTH
• heater positive (bottom terminal) connected to Vout1+ and SENSEA
• 1k resistor between ID and Vout1-
• 5.6k resistor between ID and Vout2-

2. HAKKO FX8801, HAKKO 907 (original, with PTC sensor):

• Outer shell, PTC negative and heater negative connected to EARTH, Vout1- and SENSEB
• Heater positive connected to Vout1+
• PTC positive connected to SENSEA
• 1k between ID and Vout1-
• 820ohm between ID and Vout2-

3. JBC C245:

• Outer shell (green wire) connected to EARTH and SENSEB
• Heater positive(red wire) connected to Vout1- and SENSEA
• Heater negative(blue wire) connected to Vout1+
• 150ohm between ID and Vout1-
• 5.6k between ID and Vout2-

4. JBC C210:

• Outer shell (green wire) connected to EARTH and SENSEB
• Heater negative (middle terminal, blue wire) connected to Vout1-
• Heater positive (smaller terminal, red wire) connected to Vout1+ and SENSEA
• 3.0k between ID and Vout1-
• 5.6k between ID and Vout2-

5. JBC C105/C115:

• Outer shell (green wire), connected to EARTH
• Heater negative (blue wire), connected to Vout1-
• Heater positive (red wire), connected to Vout1+ and SENSEA
• 3.0k between ID and Vout1-
• 1.0k between ID and Vout2-

6. JBC Microtweezers (PA120/AN120):

• There are 2 diodes in the original handle - they must be removed or shorted
• Outer shell of both tips (green wire) connected to EARTH
• Heater 1 negative (blue wire) connected to Vout1-
• Heater 1 positive (red wire) connected to Vout1+ and SENSEA
• Heater 2 negative (brown wire) connected to Vout2-
• Heater 2 positive (yellow wire) connected to Vout2+ and SENSEB
• 1.0k between ID and Vout1-

7. JBC Nanotweezers (NP115/AN115/NP105/NP105-B):

• There are 2 diodes in the instrument - they must be removed or shorted
• Outer shell of both tips (green wire) connected to EARTH
• Heater 1 negative (blue wire) connected to Vout1-
• Heater 1 positive (red wire) connected to Vout1+ and SENSEA
• Heater 2 negative (brown wire) connected to Vout2-
• Heater 2 positive (yellow wire) connected to Vout2+ and SENSEB
• 1.5k between ID and Vout1-

8. WELLER WSP80:

• Outer shell, PTC negative and heater negative (white, black and brown wires) connected to EARTH, Vout1- and SENSEB
• Heater positive (blue wire) connected to Vout1+
• PTC positive (red wire) connected to SENSEA
• 120ohm between ID and Vout1-
• 5.6k between ID and Vout2-

9. ERSA RT80:

• Outer shell and Heater/PTC negative (pink and white wires) connected to EARTH, Vout1- and SENSEB
• Heater/PTC positive (black wire) connected to Vout1+ and SENSEA
• 300ohm between ID and Vout1-
• 110ohm between ID and Vout2-