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
