hello
I'll have to start learning to weld and I decided to "splurge" on a bangood inverter welder.
I know it's not a machining forum, but the electronics part is interesting/
If I have to learn to weld, I can learn on a bad machine, to make things more interesting

Following Dave's advice, the first thing I did, after documenting the shipping damage (bent corners), was to take it apart.
The build is quite clean and the PCB's have a thin lacquer coating. They state it can reach 200A but I don't know if they are normal amps, or the other kind.
The front of the unit:

The main PCB has 2 IGHB's (600V, 40A), a big rectifier bridge, a 400V 680uF capacitor, a small flyback transformer for an auxiliary PSU, a gate drive transformer, a current sense transformer and a current shunt (I think), the main power toroidal transformer and the output rectifier.
There is no secondary inductor, and there is no room to add one.


The unit is NOT earthed, and there is no earth wire in the power cable.
Should I replace the cable with a 2 wire one and connect the case to earth ? Or is it safer to leave it as it is ? I could not see any connection between the case and heatsinks / PCB's

The controller section is build as a separate module, with an SG3525 controller, a bunch of transistors that seem related to the gate drive transformer, 2 op-amps (i think they are current sense amplifiers and fan control), some passives and several LED's.

It looks like it's a variation of
http://danyk.cz/svar_en.html described here:
I don't know how well it works - I've seen some clips and it seemed ok, I'll buy the required accessories and protection gear these days, and try to stick some scrap together.