On Thursday 29 December 2016 13:35:14 Jon Elson wrote: > On 12/29/2016 11:19 AM, Gene Heskett wrote: > > And there went the reversed hookup protection. :) > > No, the diodes are in the power SUPPLY, so the modular > supply is running near the designed voltage, but the load > gets a lower voltage. > > >> Jon > > > > How did you get that mod past the nuclear regulators? I'd had a > > couple mods that genuinely improved the pix coming out of a tv > > camera, rejected by lesser air force *crats who wouldn't know a 1n34 > > diode from a 4 ton transformer. Pain in the a$$ they are. They do > > not understand the technology at all, and do their damnest to freeze > > the technology at the point the maker boxed it for shipping. > > The national labs do have "electrical safety inspectors" who > check everything that has a power cord. Since this unit > plugs into a power and cooling frame, they generally don't > even look at it. Mostly they ohm out the safety ground to > frame resistance and make sure hot and neutral are isolated, > and then they are happy and put an approved sticker on it. > > Jon > Humm, VTA stuff. But at least we can get something before the next 4th of July.
And, I am now a wee bit schmardter. When I wired that box, I brought the line cord in and hooked it up to the 60 volt Z motor supply, then continued the bus to the 42 volt supplies for the X motor, and then on to this supply. Putting the filter on this supply helped, but only a few percentage points less noise. So I grabbed a couple wire nuts and bypassed the 60 volt supplies lines, including the static ground, and the pair of supplies I intended to drive the x motor with, spent about 3 hours stinking the place up about 3 weeks back, so they were removed and I ordered another, whose last day to arrive was today, but I not seen hide nor hair of it yet. So with the big supply out of the picture, it all seems to work. The about 2 volts p-p at the ground terminal of the encoder cable was a bit over 400mv, so I was able to add some code to scale the encoder to the hal file. Looking at the velocity on the halscope, its about a 20% of average with the waveform period matching one full cycle of the quadrature. D I've been using a green highliter to mark up the stuff for my averager in a printout of the mills hal file, which should reduce that periodic noise to 25% of its cuttent value, while injecting a phase delay of 2 edges gone by if it was being fed back to a PID, which it isn't. So next thought is that the noise from the big supply damaged both of the x motors supplies. So I am going to reroute the power wiring so it hits a terminal board and the little supply hooked direct, first, and from that terminal, feed the Z PSU thru this filter, and the X thru another filter I'll cabbage from another computer psu since I have more dead ones. So all three are sourced from the same terminal strip, but each of the bigger supplies will have a noise board in its power leads. Thats the plan right now anyway. I went out an picked up a dead psu, opened it up, but the line filters were laid out as an odd shaped corner of its PCB, so I clamped onto the heat sink in the mills vice, and used an old 1/8" mill to cut it out of the main PCB, driving it slowly with the mills keyboard. Now I'll make a box out of dbl-sided raw pcb to put both of them in tomorrow and fasten it to the outside of the main box and run some wire to the little 5 volter, and extend that back to a hot feed from a switch that will turn the pi and the monitor off, then run another bit of SJ from the switched duplex that will turn off all the higher powered stuff in addition to that 4 foot high powered (4000 lumens) daylight led on the bracket about 34" above the bed. And anything else plugged into the duplex above the spindle. Then we'll see how much #@$% noise we have. Good thing I've got until I fall over to get this done. The bad part is like concrete cracking, the question is not will it, but when, because it will. :) 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
