OK I'll try track down the data sheet. Failing that I'll borrow a oscilloscope and have a play. I'll post back here tomorrow
Thanks chris Regards Andrew On Fri, Feb 14, 2020, 8:51 PM Chris Albertson <albertson.ch...@gmail.com> wrote: > 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 > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
