On 03/10/2017 02:22 AM, Chris Albertson wrote: > I asked about how to characterize a servo motor here, got some good > answers. Thanks. Turns out I have some capable DC servo motors. > > Now one more question: How are people connecting these motors? It looks > to me that machine kit/LinuxCNC/EMC can read the quadrature encoder and > product PWM to drive the motor. If so then I'D need a dual H-bridge and a > power supply. It could also produce a step and direction signal and I > might use a Gecko 320X controller. You really can't generate PWM at reasonable frequency and time resolution in software. So, in general, you need a PWM generator in hardware. If you want to use Machinekit on the Beagle Bone, the PRU is kind of in-between, and probably will work. Or, Mesa and Pico Systems (my company) have devices that can generate the PWM in hardware. Pico Systems has the Universal PWM Controller, and PWM servo amplifiers to run most medium-sized servo motors. See http://pico-systems.com/osc2.5/catalog/product_info.php?cPath=3&products_id=19 and http://pico-systems.com/osc2.5/catalog/product_info.php?cPath=3&products_id=26 for more info.
The original Gecko 320 has some issues with tightness of the servo loop, ie. with some motors and power supply voltages, it allows a LOT of slack. I have not tried the 320X to see if it does better. Jon ------------------------------------------------------------------------------ Announcing the Oxford Dictionaries API! The API offers world-renowned dictionary content that is easy and intuitive to access. Sign up for an account today to start using our lexical data to power your apps and projects. Get started today and enter our developer competition. http://sdm.link/oxford _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
