That is what you do, look at the shape with no load. the 10X probe did that.
I have to admit my experience with encoders is mostly wth directly connecting to microcontroller pins. No need to opto-isolate if everything is driven from the same driven power. IIt would seem then that those optical couplers are hard to drive and maybe they were designed to be driven by mechanical limit switches. In any case I don't see a reason to use an optocoupler when the device you are connecting in an optical coupler. I think if you drive the motor encoder from the same power and gund at the BOB you are good. As for removing those chips. Buy a cheap chinese hot air solder station, then un-soldering even a 16-pin through-hole DIP chip is easy. Before I owned one I used to clip all 16-pins from the chip and toss the chip in the trash then un-solder each clipped off lead pin one at a time. Of course the hot air is designed for SMT but it make through-hole very easy. On Wed, Nov 18, 2020 at 9:38 AM Gene Heskett <ghesk...@shentel.net> wrote: > On Wednesday 18 November 2020 11:50:26 Chris Albertson wrote: > > > Your encoder is likely just a bare phototransistor. You might need a > > 10K pull-up. THat might be enough > > [...] > > > Disconnected from the bob, it does do a > > > rail to rail swing with a rise or fall time in the very low > > > microsecond range. > > Read this last sentence again Chris, the rise time is just a microsecond > when disconnected from the BoB, Connected to the BoB, fall time is > unchanged, but rise time looks like it having to charge a .1uf cap. > Tested now with 3 Sainsmart BoB's. I can see a change in the curve as > it goes above the opto's on point at about 2 volts, the rc curve > suddenly gets extended to about double. > > I can still see the change in the shape of the curve at the output of the > encoder with a 1500 ohm pullup. It gets about 10x faster with a 1500 ohm > pullup, but how much can it sink? > > Its nice and square just driving the scopes 10x probes. This is beginning > to look as if I am going to have to pull the optos out of the sainsmart > BoB's. > > Its a PITA, but I've done it before. And I normally install a couple > 1n914's as rail snubbers to protect the gates of the HCT stuff on the > card. > > So I may as well get to it. > > Thanks Chris. > > > > Thanks all. > > > > > > 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) > > > If we desire respect for the law, we must first make the law > > > respectable. - Louis D. Brandeis > > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > 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) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > _______________________________________________ > 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
