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
> >>
> >>
> >>
> >>
> >> _______________________________________________
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> >> Emc-users@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>
> >
> >
> > --
> >
> > Chris Albertson
> > Redondo Beach, California
> >
> > _______________________________________________
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> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
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