A while back I played with a KBIC speed controller which demonstrated fairly good torque at high and low speeds. I was curious about how a PWM amp would do, so I set up a Pico amp to a parport PWM signal at about 25kHz and was surprised to find that low end torque was much less. I thought the PWM frequency might have had something to do with the torque issue, so I made a similar setup with a 50kHz PWM signal from a Pico PWM controller and got similar results. Then I got to thinking, the Pico amp is a PWM to voltage converter. The motor torque will be the torque for the voltage that the motor happens to be driven with at the time. I thought the KBIC had feed-back during the zero crossing period ,but I didn't realize how important it is. So, in order for the PWM amp to have good torque and speed control, feedback needs to be set up. Does this seem correct?
-- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC/EMC CNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending Craftsman AA 109 restoration Shizuoka ST-N/EMC CNC) ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
