I gotta man up too today for the Lincoln plasma cutter on the bench that has some fault in the cutting arc supply.
Mains bridge, IGBT's or drive circuit IDK but will carefully work my way through it.
Gotta theory of operation overview diagram only that's little different from what I imagined anyways.
Shitty wet day in NZ today and been working on this ^.
Found a service manual online with a reasonably detailed circuit layout and a good amount of test points to help you find areas where faults might be.
Lincoln Procut25
https://www.red-d-arc.com/pdf/Procut25%20Service%20Manual.pdfMuch poking and prodding ensued until I came across a 12V miniature DPDT relay with a dimple in its hat.
It's listed as RL1 on P25 and apparently controls the HF start arc but with its guts cooked some so the NO contacts remain closed the unit fails to start as safety circuits kick in to prevent it.
Replace the relay, easy one might think but not.
![Rant :rant:](https://www.eevblog.com/forum/Smileys/default/rant.gif)
Tried RS, E14, Digikey and Mouser so far but not finished although I am for today.
![Indifferent :=\](https://www.eevblog.com/forum/Smileys/default/indifferent0023.gif.pagespeed.ce.nyXMDasYXd.gif)
> Finder Type 40.61 16A 230VAC rating. 12V 205 ohm coil <
Some are close but most are all around a pigs arse but no pork !
![Flogging A Dead Horse :horse:](https://www.eevblog.com/forum/Smileys/default/DeadHorse.gif.pagespeed.ce.kBWvHKqCd1.gif)
Need to get this one done as a really interesting power control module from a 13 KW 3 axis programmable mill awaits.
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif.pagespeed.ce.oZptHNcbsD.gif)