2 in 1 SMPS Welding Machine and Power Supply

Welding machine project is a two-in-one SMPS Power Supply and Welding Machine built on the STM32F103 Development board. Welding Machine circuit Working frequency 45khz. Toroidal cores are used in power and driver. Voltage current information is displayed on the Oled LCD screen and adjustment is made with the encoder.

Thanks to @devrecii for preparing the project.

SMPS Power Supply and Welding Machine Circuit Schematic

Actually I was going to do it for mig welding but I couldn’t do the mechanical parts myself if I bought it the torch and wire drive motor cost half the price of the machine so I stopped working here.

The circuit looks complicated but it is not at all, the outputs are very clean only the amperage reading is not linear at low current but it works great in this way.

For button mode Mig, MMa, Power supply. All three work differently. For example in mig the volt is adjustable but full amperage is given to the output, in arc welding the output is full volt and the amperage is adjusted. In power, all are adjustable the power output is different because if welding is done the capacitors there will burn and explode in a short time.

I drew 200 amps at 14 volts it really gives 200a after 14 volts the ampere drops parabolically according to the increase in voltage it is about a 2500 watt machine. The output winding number of the main transformer should be increased of course the filter coils that come later should be large and have many windings then it can give 50v 50amps or more.

The stlink program does not recognize the sim and out files in the zip file I gave. There is a *.bin file and *.hex file here, which can be loaded directly to stm32 with the stlink utility program.

CAUTION The welding machine circuit works with high voltage, be careful, pay attention to the capacitor connections. If you connect the + – poles in reverse, there may be big explosions at high voltage. Before operating the circuit, use a Fused Electric Line and protective glasses.

Source: picproje.org/index.php/topic,83985.0.html