Welder Causing Issues with our plasma computer

[John Igoe]

We are having some kind of trouble since we got our new plasma table. Currently have a TIG welder near the computer case for the plasma table. Whenever we TIG weld aluminum (AC), the mouse and keyboard will cease to be recognized by the plasma table's computer. We have to either restart the computer or unplug and plug in the mouse and keyboard usb cables. We have tried adding those ferrite black clips to the cords of the mouse and keyboard, and I tried wrapping the computer in copper screen/mesh. now the keyboard and mouse are lost while welding, but come back when the welding stops.

Any solutions or advise?

Thanks
-John

 

[corkyg]

Sometimes EMI is simply akin to black magic. I recall years ago, we built an A/D-D/A convert bof for Grumman's Fi14 Tomcat. The EMI when installed in the F-14 was big. We tried everything to no avail, but one day, a tech undid all the beautiful wiring harnesses in the box, and a test was run with jumbled wires. No EMI! So, the fix was easy - undo the neat wiring and jumble the wires in the box. EMI problem solved - engineers hated the jumbled wires, but it worked.