Can't we run an AC servo in a + or - torque mode, based on a + or - control voltage applied to the servo drive? Clockwise rotation (torque force) for + and CCW for a - control voltage. The servo tries to maintain a commanded torque output. Forcing the motor shaft to rotate. I would think DC servo drives will do the same. Dale
--- On Sat, 12/20/08, Javid Butler <javidbut...@cox.net> wrote: From: Javid Butler <javidbut...@cox.net> Subject: [Emc-users] Off topic-Electrical design help To: emc-users@lists.sourceforge.net Date: Saturday, December 20, 2008, 1:08 PM Is there a reason such as cost or space that an off-the-shelf drive for the motor cannot be used? Some of the new drives have the capabilities that you are looking for built in. I was just hearing the other day about a Siemens drive that is even line power regenerative-when the motor is being used for braking the energy is not dissipated in a resistor bank, but is put back into the power line. So the braking energy is actually powering the lights in the building (for example-you could thing of it as running the air conditioning too). The energy efficiency is not quite the point here, just that a drive may be available for that motor that already has the drive/braking capability you need. Unless you are wanting to work it out for the fun of doing it, which is something I completely understand! Javid ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
