Asking here because I see a lot of people retrofitting old equipment. My wife has a long arm quilting machine that was made by Proto quire a few years ago. They were an industrial equipment maker that is long gone. The basic operation of the machine is to watch x and y encoders and stitch the fabric keeping a constant (ish) distance between the stitches. I suspect that they are just calculating a velocity off of the encoder movements. This feeds the differential inputs of a Servo Dynamics SDFCC1020-12 servo amp that drives a brushed dc motor from a 90 volt pdc power supply.
The servo amp was slowly dying with power on faults. I revived that by replacing the electrolytic caps but the thing is still not right and the alignment procedure won;t get to the correct motor rpm without causing drift as zero machine movement. It slowly stitches. If I tune that out I won't go the right speed so the stitch spacing is wrong. I am goi that feeds into the H bridge on the output but am not holding out much faith. Any suggestions for a brushed DC servo amp that will handle 90 volts and works with differential input? The specs on the current amp are 118vd peak, 112vdc continuous, 20 amp peak, 10 amp continuous with a 16kHz pwm frequency. Not real critical on any of them other than being over 90 volts continuus. I doubt that they are anywhere near the 10 amp limit. Any suggestions on what to put in as a direct replacement. I am about at the point of using an arduino to read the input on an a to d pin and pwm a mosfet. The arduino will go fast enough in fast pwm mode. Dave _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
