Hi Again Torbjorn.
Thank you for the extended information about the transistors. I have got the BC 141-16 transistors and change them all, as the others didn't look very healthy either.
However, after taking them out, i tested them, and they were working fine, but now I have new shiny transistors where I can read the text.
If you are reading this? I encountered another problem, and that is the transformer for feeding the card and the relay/contactor.
The primary windings were burned and ther was no power anymore on the secondary side, of course.
First I contacted ESAB in hope to get at least their scematics with information about voltages on the card, to determind what
voltage I need from the transformers secondary side.
The answer was that they no longer had any documnentation for the Smash Weld 180, as it was too old. They only had the user manual, and sait that parts were no longer available for this machine
Next, I tried to unwind the primary, and counting the windings, but I came to a stage where they were impossible to unwind anymore, as the Cu wire broke.
I now have the CU wire (0,22mm with coating. 0,2mm without coating) and my intention is to rewind it again, back to the original.
I have also a formula to calculate an average transformer core, but here are variations on thid from one manufacturer to the other, resulting in different
output voltages, as the secondary windings are beeing used as they are.
To get the transformer correct, I need to know the voltages on the secondary side (to the card and the contactor). This way I can wind it according to my formula and then measure the voltage.
From this I can calculate if I need to remove or add windings, to get the right voltage.
It would be extreemely helpful, if you could have measured the voltage output on the primary side on your transformer.
Could you please help me with this?
I understand that in this
thread, you are the one with most knowledge about electronics and the welding machine.
In return, I can send you all the documentation I have gatherede and made myself for this project.
If you give me the voltage output, i will return with all information needed to rewind the transformer from scratch, if something happens with your transformer.
The troubble is that this information is lost, and you have a burned transformer, there is no way to repair this again.
I really appreciate your help