That's related to my tig inverter project.
I put together (on a wooden board for now) the timing circuit and semikron 23's. Since I do not have connectors yet (hopefully today or on Monday) I used alligator clips to connect the timing circuit and power to one of the semikrons (just the low input).
After replacing a 5k pullup resistor on the comparator with a 1k pullup resistor, the semikron board started producing sensible output.
I am now quite hopeful that in a couple of weeks I will have a working prototype that I could test with a small power supply.
I want to assemble everything on some temporary platform (like a wooden board) and test it using successively harder loads, make sure that the dead time is minimal to nonexistent, etc.
The general plan is as follows (regression testing after every step):
- Use a wooden board as a base for everything
- Assemble the circuits properly using proper connectors
- Machine proper copper connectors for the paralleled H bridge
- Implement adequate snubbing circuit
- Give this system a final test
- Install controls where they belong on the welder
- Go away from wooden board, fabricate a properly shielded and cooled metal enclosure, possibly with both intake and exhaust fan (I have more fans than I care to admit)
- Assemble everything together inside the welder