Re: [CAD_CAM_EDM_DRO] DC Motor types

A&K ERWOOD wrote:

> Jon,
>
> Thanks for getting back to me.
>
> By AC Leg I mean the AC terminal of the Bridge. I try a little artwork.
>
> ------------------------------------------
> ------------------ Power (+)
> / \
> / \
> / \
> - { - + } --------------------- To
> Field
> - \ /
> - \ /
> - \ /
> - ------------------------------------------
> ----------------- To Arm
> ----------------------------------------------- To Field
>
> Power
> (-)----------------------------------------------- To Arm
>
> I hope this explains it a bit better. If the art is readable.

Well, as I explained before, you don't need the bridge. You want constant
excitation of the field winding, at the specified voltage. Assuming there is
a separate DC power supply for the servo amp (and this is true for the Gecko
drives) then you just connect that DC supply to the field terminals, and leave
the field power on all the time the main DC supply is on. This exactly
simulates
the permanent magnets in a PM DC motor.

You connect the armature terminals of the motor to the servo amp outputs.
And, it should have good torque, if the motors are properly sized for the
task.

Jon