On 01/02/2017 12:38 AM, Gene Heskett wrote: [snip] > Bring up power to the motor supplies and its injecting enough noise on > the SPI bus that it all goes in the crapper. Once I stopped everything > but lcnc, and was walking around the tail end of it to see what I could > see on the scope, this after putting an isolator plug under the scope, > and z took off and ran about 2" all by itself. There is not currently a > connection from house static except that which it gets from the 254 volt > hubble socket. Hooking that up seems to make it worse, confirming the > ground loop theory. [snip]
I'm a bit guessing here (swimming without schematics), just thinking out loud. Are the PSUs you are using in a metal chassis? Is that chassis maybe connected to its GND output terminal (and then GND shorted through mounting, maybe AC-coupled)? Or, do you have a grounding earth connection that could span power supplies through the GND (that could also be AC-coupled)? -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
