Greetings everybody; Now I am asking a question that I should know the answer to.
It looks like, from the evidence so far, that this 5v 4a little switchmode psu should be sent to the fcc and let them ban it from ever coming off the boat or airplane on US soil. Its "static" ground terminal is common to the case, and I have now grounded it by way of a couple flat braided ground straps about 5/16" inch wide, back to the ground bolt in the bottom of the box. Ditto the static ground on the z motors 60 volt psu. House static coming in is now also bolted at that stud. The scope probes ground lead is on that stud, the clipon probe is clipped to one of the ioconnectors ground pins. That point is bouncing around 2.5v p-p with the switching activity in that psu. That bolt s/b common to the lathes bed casting thru the bolts that mount it on a post bolted to the chip pan, which is braced by an angle iron bolted to this post, with the end of the angle, about 8" away, bolted solidly to the bed casting at the other end. I purposely did not connect anything in the at667 encoder wireup, to the frame anyplace. If I could find a good, real dirt ground for the scope probe, I take bets that the whole latch is bouncing at least 25 volts p-p to that real ground. The only way I can see ATM, is to install some "longitudinal" filters, therefore chokeing that noise back into the psu instead of giving it something to work against in the form of a solid connection to the powerline. I can source such a filter from Dave at the tv station as I know he has a pile of failed monitor pcb's, all of which will have good filters we can excavate. Or should I take the chance that the next one I buy on fleabay, would be quiet? Your call. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ 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
