Tcmtech

Thanks for the suggestion. Sockets are a great idea. I'll get back to you when I have these replaced.
hoader

 

Hi everyone!
This project was put on hold for a while but now it is started again. I installed the sockets and inserted the chips. I saw the variable width pulses to run the wire feeder and the soled state relay.using my scope. I had to short the terminals that go to the trigger gun to activate that part of the circuit. I then plugged the board into the welder and flipped the power switch. I heard a snap and saw a flash towards the back of the welder. It damaged a couple chips and is doing what the welder did in the beginning. I wasn't prepared for what happened meaning I don't know where the flash came from or where the noise originated. The circuit board is at the front panel of the welder behind the controls.I can think of a few potential causes but I also don't want to burn up several chips through trial and error. I predict there will be many errors. Is there an output driver that can supply higher currents and more resistant to burning out if there is a reverse voltage spike? Is there another easy way to buffer the board from the welder connections? How do I test for these spikes? what else should I try?

Thanks hoader