On Tuesday 09 July 2013 23:13:46 Jon Elson did opine: > Gene Heskett wrote: > > But if I do that, the switch mode stuff itself will run reasonably > > cool, so where does the heat actually go? Its got to go someplace, I > > just haven't thought it through. > > Using the inductance of the motor, the switching supply changes from a > buck converter in normal mode to a boost converter when braking, > and pumps the energy back into the DC supply. Fancier drives > have a braking resistor on a switch transistor, and when the DC link > exceeds some limit it turns on the braking transistor. > > Jon > This driver doesn't appear to do that. Pulling a treadmill with its heavy drag, it wouldn't be needed. If I have it running at 1000 rpms at the spindle, and I type s300 enter in mdi mode, it will coast, powerless for 5, maybe 6 seconds before the PID kicks back in to hold it at 300. This drive is capable of running a 4 or 5 horse motor as it can make 25 amps, but the breaker is a 9 amp thermally driven variety, saved from the old drive setup. Sweet driver, & dead silent but not a bidi servo so my .hal file has some tricks in it to run a g33.1. Getting a faster stop is the target and I am sequencing the braking resistors with some relays and a wcomp module now.
I am not out of ideas just yet as the transition of the direction is detected by a one shot timing out, and shortening that timeout is one way to hit the direction change when its not quite stopped, perhaps 1/2 turn from a full stop. If I had a hall effect current probe, I could see when I was approaching the blow or bend something point to 'optimize' the reversal. But in that regard, I am currently blind & feeling my way along incrementally. Must be time to start prowling ebay for a probe I can afford. ;-) Thanks Jon. > ------------------------------------------------------------------------ > ------ See everything from the browser to the database with AppDynamics > Get end-to-end visibility with application monitoring from AppDynamics > Isolate bottlenecks and diagnose root cause in seconds. > Start your free trial of AppDynamics Pro today! > http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clk > trk _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Women, when they have made a sheep of a man, always tell him that he is a lion with a will of iron. -- Honor'e de Balzac A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
