Hi Gene, Want to test one of my 5v 3a regulated power supplies?
JT On 12/28/2016 4:33 PM, Gene Heskett wrote: > 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 ------------------------------------------------------------------------------ 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
