On Tue, Aug 6, 2013 at 9:41 AM, dave <dengv...@charter.net> wrote: > Too early in the morning and still on first cup of coffee but: if you are > within the 1/4 > step (null) then increased feedback of some kind won't fix it. >
It does fix it. The feedback will cause the control loop to shift the commanded position away so that you ARE on the upslope of the torque curve. Its fundamentally how servos work. You need to develop Q(quadrature) current(flux) to get torque. The D(direct) current doesn't do any work. Technically, once you have feedback in a stepper system you can fully servo it and not require any 'holding current' if the application doesn't currently demand it. The fixed current most stepper drivers use is only because they don't know where they are in the DQ frame. So they provide a ton of D and shaft error shifts the angle to produce some Q. ------------------------------------------------------------------------------ Get your SQL database under version control now! Version control is standard for application code, but databases havent caught up. So what steps can you take to put your SQL databases under version control? Why should you start doing it? Read more to find out. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
