Just a quick note here well I'm on the snowboard chairlift. I have a mesa ency splitter encoder board and I'm running a powered 12v encoder (actually it's a 5-30v encoder). into that fine. This is against official advice but the card was 30 bucks and figured what Do I have to lose. Its been fine for 5 months so far on a big cnc Mill
On Mon, 11 Oct 2021, 09:04 Peter Hodgson, <peterjohnhodg...@gmail.com> wrote: > Hi Chris, > > The encoder datasheet gives a voltage range of 10-30vdc so I don’t think > direct connection with 5vdc would be an option. > > Would a direct connection via voltage dividers eliminate the ‘ghost > pulses’ being picked up by the Pico board? > > The encoder won’t be running above 3,000 rpm. > > Pete > > > On 10 Oct 2021, at 19:00, Chris Albertson <albertson.ch...@gmail.com> > wrote: > > > > Is your math right? Yes, I get 83 KHz for a 500 line encoder at 10,000 > > RPM. Yes that is < 1% of the isolator's rated speed (of 10 MHz) > > > > But the schematic had an RC low pass filter in the encoder output that > > would have prevented the system from working above about 1000 RPM. I see > > this is gone now. > > > > But why are these isolators even needed? Why not simply operate the > > encoder at 5 volts? > > > > Or if you must run the encoder at 12 volts, you can do level translation > > with a resistor voltage divider. > > > > There is nothing yo isolate. The entire system runs on a common ground > and > > there is no high power devices in the schematic and I assume the entire > > system is in one building with no long (100 meter) cables > > > > If you are worried about accidents blowing up the controller, use diodes > to > > shunt any transients. But really there are no inductive loads > > > > > > > > > > > > On Sun, Oct 10, 2021 at 10:25 AM John Dammeyer <jo...@autoartisans.com> > > wrote: > > > >>> From: Gene Heskett [mailto:ghesk...@shentel.net] > >> > >> > >> > >>> If the opto's are fast enough, you should be > >>> fixed. A 500 ppr encoder s/b fine. A 1024 or 1000 requires a faster > >>> opto. > >>> > >> > >> HI Gene, > >> Comparing the cheap far east BoB optos with the HCPL2621 is apples and > >> oranges. > >> > >> A 2500 line encoder still only creates 2500 pulses. The quadrature just > >> looks at two lines and 2 edges for 10,000 edges. But the max speed of > his > >> encoder is 10,000 RPM which in RPS is 166.7 and would result in 417kHz > >> which is 4% of the opto max 10 Mbps capabilities if the encoder was > 2500 > >> line. > >> > >> But his is 500 line so at 166.7 RPS is 83kHz which is 0.8% of opto > >> capabilities. > >> > >> > >> John > >> > >> > >> > >> > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
