First step is to understand (1) what you have and (2) what you need. So, If the spindle revolves one time, How many cycles of the sin wave do you see? What is the amplitude of the sine wave (in volts peak to peak)? Does the amplitude change with the spindle speed? You need to either read this information from the encoder's data sheet or measure it
I assume you need a 5-volt square wave quadrature signal. A potential problem with square wave converters is noise. But lets first see what the sin wave signal looks like. On Thu, Feb 13, 2020 at 11:03 PM andrew beck <andrewbeck0...@gmail.com> wrote: > Chris. I'm still learning electronics. Could you expand a bit on this > please. > > Maybe draw a napkin sketch of it. Sorry to be a bit slow on the uptake > > On Thu, Feb 13, 2020, 5:46 AM Chris Albertson <albertson.ch...@gmail.com> > wrote: > > > A sin and cos are 90 degrees apart. All you should need to do is > threshold > > the signal and you have A/B quadrature. Many ways to threshold it but > > you want the one with least noise. > > > > A simple way to convert a sin wave to a square wave is to amplify then > clip > > it with diodes. A comparator can also convert the signal. > > > > The point to remember is that sin/cos is quadrature and all that is > needed > > is some signal conditioning. > > > > On Tue, Feb 11, 2020 at 10:46 PM andrew beck <andrewbeck0...@gmail.com> > > wrote: > > > > > Hi guys > > > > > > wondering if anyone has any ideas here. > > > > > > I have a heidanhain spindle motor that runs up to 10000 rpm and has a > 5v > > > sin cos encoder on it. I am currently controlling the motor with a > > > schiender vfd. I am talking to the support engineers here in New > Zealand > > > about buying a encoder card so I can get better low down torque. If I > > run > > > the card in full encoder closed loop control in the vfd I can get 200 > > > percent of the torque right down to 0 rpm for 30 seconds or so which is > > > pretty useful. I am currently just running the drive in Variable > > frequency > > > control which rapidly looses torque at low rpm. > > > > > > Anyway they have a bunch of cards I can use but don't have a encoder > card > > > that is suitable for sin cos encoders. I have no trouble changing the > > > encoder but am not sure if I can get a source of encoders that spin up > to > > > 10k rpm. > > > > > > Anyone have any suggestions? > > > > > > regards > > > > > > Andrew > > > > > > _______________________________________________ > > > 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 > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
