jcyw Digital Players - Supercapacitor Spot Welding Machine - Modular Plan 1.0

Based on the open-source versions of supercapacitor spot welders shared by forum experts, and incorporating my own understanding, this version is Modular Project 1.0. The iterative development of the Modular Project continuously feeds back into subsequent integrated versions and various variant models. Through modular design, changes to one part do not affect the whole.
Friendly reminder: In response to requests, the schematic and PCB have been re-uploaded; they should correspond, please verify yourself.
The following is a brief introduction to Modular Project 1.0:
Modular spot welder (control + MOSFET + explosion protection + equalization), 0.2mm copper, 1.0mm iron sheet, 3-4kA overall internal resistance 1.3mR, PCB self-designed, 42*42mm/36*36mm ultra-small board, modular design, multi-layer stacking, achieving various forms, firmware can be flashed with the open-source version or other open-source firmware. Performance: Can weld up to 0.2mm copper/1.0mm pads. Highlights: 1. Single-sided board design, convenient for heating table processing. 2. Type-C 5V power supply. 3. Open nose directly connects to capacitor tabs, eliminating intermediate steps and reducing internal resistance. 4. Simple and efficient, lowering the barrier to entry and making it accessible to the general public. Continuously being updated.
Some theoretical knowledge can be referenced: 1. Internal resistance calculation: The system consists of several parts: soldering cable + soldering pen + main control board + MOSFET board + supercapacitor. Soldering cable: 16 sq mm 1.25 mΩ / 25 sq mm 0.8 mΩ / 35 sq mm 0.6 mΩ; Soldering pen: 0.3~1 mΩ (all copper will be much smaller, brass clips are slightly larger); MOSFET board: 0.1~0.05 mΩ (a single MOSFET 228/8409 is 0.6 mΩ, for 6~12 transistors in parallel, divide by the number 6~12); Supercapacitor: 0.3~1.2 mΩ (a single supercapacitor is 0.3, series and parallel connections reduce, for example, two series are 0.3*2=0.6, two series and two parallel are 0.3*2/2=0.3, and so on). Total internal resistance sum: 0.8 + 0.3 + 0.05 + 0.6 = 1.75 milliohms. This is the ideal state. In reality, there is also the internal resistance of the connecting copper busbar screws, which is calculated as 2.5 milliohms. 2. Spot welding current calculation: Voltage of two series capacitors 5.4V / 2.5 milliohms = 2000A. This is the peak value under ideal conditions. The actual value needs to be measured with instruments. Note: For large-scale spot welding, it is best to charge and use simultaneously to maintain a voltage of 5.4V.
Please see the pictures and videos for the effect.
Let's make friends through playing and popularize spot welding. The vision is that everyone can play with spot welding machines. Welcome to exchange ideas. Please leave a message. I will not post the group number.
Thank you.
Below are some photos for reference. Please indicate the source when reprinting. Thank you.