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 and 1/4 power selection, so only simple single winding 24V 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, wuth 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 on 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)
• JBC C245 (series or separate TC)
• JBC C210 (series TC)
• JBC Microtweezers (2 separate heaters, each with series TC)
• JBC C105 (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 (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).

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:

• 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. 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-

8. 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-