Arduino-based spot welder controller project.
Pulses a high current transformer with the set millisecond value. Intended for spot welding batteries, but it can be adapted for other things too.
Parts list:
- Modified microwave transformer
- KY-040 rotary encoder module
- TM1637 4-digit display module
- SSR-25DA solid state relay
- Arduino (I am using a Nano. A 5V Pro Mini should work too, although I've had trouble getting mine to program.)
A TM1637 4-digit display module is used to show the set value, to save on GPIO pins. A rotary encoder is used to set the millisecond value. A 25A solid state relay is used to control the mains input of the modified microwave transformer. A foot pedal from a tattoo machine is used as a trigger for the code.
The Grove 4-digit display library (https://github.com/Seeed-Studio/Grove_4Digital_Display) is used for interfacing with the TM1637 module. This can be found in the Library Manager in the Arduino IDE.
A microwave transformer was modified by cutting out the secondary winding, and replacing it with 3 turns of jump lead wire. The output is around 2.5V.