Kirk Wallace wrote: > > These are a little embarrassing, but here are some pictures of my > Pico/Pluto setup: > > http://www.wallacecompany.com/machine_shop/Pluto/ > > The cores of the inductors seem to be heating and not the copper, so it > takes a while for the heat to be detected. It seems that one or the > other inductor heats up dependent on direction of the motor rotation. I > seem to get no heating at zero speed and have only done brief testing up > to 30% speed. > > The upper trace is the PWM signal at the amp connector. The lower trace > is the direction signal at the amp connector. >
Wow, I thought I was the only one who did that "desktop computer" thing! Well, I'm a bit mystified by this core heating thing. It is not unusual for them to get warm, and if you are running the servo motor at constant speed for several minutes, then I wouldn't be terribly surprised at this. The hot core would be on the side that is sending a positive voltage to the motor. On the other side the ground transistor would be on all the time, and that inductor would run cooler. You say you are experiencing this with only 50 V on the DC supply? I can do some experiments here to see whether I can duplicate the result. I was actually running one of these amps on the spindle of my minimill tonight, but the program was reversing the spindle a bunch as I've been experimenting with rigid tapping. I didn't notice any unusual heating there. And, it could be this feedback thing, too. Jon ------------------------------------------------------------------------- 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
