I hadn't explained myself well enough to Peter. The 0.1uF caps go to pins 8 and 5 to bypass the 5 volt logic supply. Either 0.1 or 0.01 are fine. Just keeps the noise from the output switching down a bit.
John > -----Original Message----- > From: Chris Albertson [mailto:albertson.ch...@gmail.com] > Sent: October-09-21 1:10 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Fwd: Rogue Index Pulses > > Using the opto ioslators as voltage translators should work. Note the data > sheet has the words "not recommended for new design" on it. There is > likely a newer part. But maybe you have these on hand already? > > These isolators will do 10 Mbits/second, likely fast enough. The > bottleneck is the RC filter made using the 1K resistor and 0.1 uF cap (time > constant of 0.0001 second) > > One other idea. Can you run the encoder from a 5 volt power supply? > Then there is no need for level conversion > > At 1,000 RPM and 500 pulses per revolution you get 8333 pulses per second. > Your low pass filter might be a little too aggressive. But I don't know > the max shaft RPM. But do check this. > > On Sat, Oct 9, 2021 at 12:39 PM Gene Heskett <ghesk...@shentel.net> wrote: > > > On Saturday 09 October 2021 15:22:29 Peter Hodgson wrote: > > > > > Hi John, > > > > > > Thanks for sharing the drawing. Yes, I would like to get things > > > properly drawn when I get the time. > > > > > > In the mean time....... would you mind having a quick look at the > > > revised schematic on the following link to check I have placed the > > > capacitors you suggested in the correct place when using the HCPL2631 > > > ?? > > > > > > https://www.purbrookengineering.com/index.php?option=com_content&view= > > >article&id=11 > > > > > > > > > I notice on your drawing you have 'Earth' and FGND. What's the > > > difference? > > > > > > Pete > > > > > That looks better, as long as the opto's are fast enough. Verify that > > with a o-scope. And the halscope is not fast enough, use a real one. But > > please don't use yellow on white for the signal wires, they disappear in > > the pdf. :( > > > > > On 09/10/2021 18:18, John Dammeyer wrote: > > > > Hi Peter, > > > > I find it helps to draw a wiring diagram of where things are wired. > > > > That�s different from a schematic which just shows how things are > > > > connected. > > > > > > > > For example, I've attached the old schematic of my mill wiring > > > > (before I removed the two HP-UHU drives and wired in the quadrature > > > > encoder for the spindle into the second Chinese BoB). Note to self: > > > > Really must update now that I have AC servos on everything. > > > > > > > > I have colour codes on there for wiring. But it does not show the > > > > actual wiring paths. For example the 24V comes out of the Power > > > > Supply and splits in two directions. One to the DIN Rail for the > > > > MiniBoB->STMBL drive, the STMBL drive and 24V-16V UHU power supply. > > > > From there another DIN rail set of terminal blocks to run power out > > > > to the Bergerda Spindle Interface and now the Bergerda interface > > > > boards. > > > > > > > > But the drawing doesn't actually show the DIN rails or wire lengths > > > > so there's no way to see if the 24V system has ground loops etc. > > > > Not from the Schematic. > > > > > > > > So I still have to create a new 'mechanical' wiring diagram that > > > > shows where rather than how things are connected. > > > > > > > > John > > > > > > > >> -----Original Message----- > > > >> From: Peter Hodgson [mailto:peterjohnhodg...@gmail.com] > > > >> Sent: October-09-21 1:38 AM > > > >> To: Enhanced Machine Controller (EMC) > > > >> Subject: Re: [Emc-users] Fwd: Rogue Index Pulses > > > >> > > > >> Thanks Chris, yes, I will change the shielding ground to the > > > >> controller end and isolate the case. > > > >> > > > >> Is it best practice to run the 5v and 12v ?grounds? back to the > > > >> original 24v power supply 0v? > > > >> > > > >>> On 9 Oct 2021, at 00:53, Chris Albertson > > > >>> <albertson.ch...@gmail.com> wrote: > > > >>> > > > >>> ?I'll say what Gene said. I'd bet on a groubing issue. The > > > >>> schmatic has an error, a groubd wire ismissing and also shows > > > >>> random crossing grounds. Run everything back to the power supply > > > >>> minus post. > > > >>> > > > >>> Also you be much better if the sheild was grounded to the > > > >>> controller end. Never us a machine and it's mounting bolts as > > > >>> grounds. > > > >>> > > > >>> > > > >>> -- > > > >>> > > > >>> 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 > > > > > > _______________________________________________ > > > 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, 1940) > > 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 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
