On Monday 12 September 2016 22:14:38 Jon Elson wrote: > On 09/12/2016 12:43 PM, Gene Heskett wrote: > > Greetings all; > > > > I see by the spec sheet that the allegro 667 gear sensor can sink up > > to 25 mills. > > > > But with 3 such sensors on the end of a long cable back to the > > breakout board, probably 7 foot by the time I get it routed, I am > > concerned with the potential for crosstalk noise in spite of putting > > a bypass capacitor on the encoder itself. > > Just don't source any more current than you actually need. > I have 3 of these on my spindle encoder, the cable is > certainly more than 7 feet, and right next to a VFD-powered > motor. No problems so far. > I have the pull-ups at the sensor end, and they are 1 K > Ohm. I do have a .1 uF (or possibly 1 uF) cap across the > power at the sensor end junction block, that is maybe 4" > from the actual sensors. I used 4-conductor shielded cable, > with the shield as the ground return (I know, not best > practice, but I didn't have 5-conductor shielded cable). > > Jon > I've had a 6 foot piece of star-quad cable doing that on the little monster lathe for several years. It just works. And its cooked spaghetti pliable to boot. But I just found an identical 3 foot hunk of it, running an 8 wire 425oz motor wired parallel, is heating noticeably. Unfortunately, the next heavier gauge of that cable has been "out of stock" for 4 or 5 years. Its just enough bigger that its quite hard to put a neutrik connector on it. So I'm stuck using a much stiffer cable I can get at the electrical wholesaler in Clarksburg, and bigger cable-chain too.
> ---------------------------------------------------------------------- >-------- _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users 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> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
