Jon Elson wrote: > > I did have some non-CNC interference from my mill's VFD, mostly > to my computer monitor. I put a Corcom-type line filter box on > the line in to the VFD, and it solved the problem. > > Jon
I had the same thing with the fractional HP VFD on my drill press. It was only running a 1/2 HP three phase motor, but it put enough interference back into the AC line that you couldn't use an AM radio anywhere in the house. During baseball season that was unacceptable. A Corcom filter cleaned it right up. Filtering gets a lot more complicated when you start talking about a few HP, but for fractional HP, a 10A Corcom will do wonders for RF interference. Noise getting into encoder signals is NOT the same as AM radio interference. Although a Corcom can't hurt, I would not expect it to help much with encoder noise. That needs to be addressed by grounding, shielding, and use of differential signals. I seem to recall Kirk saying that he has a short run of single ended signals between the encoder itself and the differential driver board. That board should be as close as humanly possible to the encoder, and its ground must be connected to the encoder ground. Any stray currents flowing in the grounds between the two items will result in noise. Regards, John Kasunich ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
