Steve White wrote: > Jon, > > I'm the guy from the CNC Workshop that had the Yaskawa encoder > documentation you needed for testing the resolver to quadrature > conversion. I also had the Panasonic servo motors / drives and a lot of > other junk for sale there. > > Have you looked at the AD650 (also from Analog Devices)? I've never > used any, but the data sheet looks like it might have potential. Here's > a (really long) link to the data sheet. The AD650 is easy to find on > their web site too if this long link fails. > > http://www.analog.com/static/imported-files/data_sheets/AD650.pdf#xml=http://search.analog.com/search/pdfPainter.aspx?url=http://www.analog.com/static/imported-files/data_sheets/AD650.pdf&fterm=f/v&fterm=f/v&la=en We keep going around and around on this, and I keep trying to explain why ONE F-V converter won't work, the problem is encoder dither. If the encoder is dithering, then the F-V gets a significant rate of counts, and the direction is flipping back and forth at a high rate. This will drive a servo system crazy. One possibility is to use two carefully matched F-V converters into a opposite inputs of a differential amp. Feed positive encoder counts to one, negative counts to the other. The dither will just cancel out. I may have to mock this up and try it out. It may be better than a complicated digital fitering scheme, but it likely will have to be carefully adjusted on the bench. The digital scheme should have minimal adjustments.
Jon ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
