Re: [CAD_CAM_EDM_DRO] Re: Field wound DC Servo

babinda01 wrote:

>Hi Jon,
>Thanks very much for getting back to me, and for your advice. I
>will do the tests you suggested this morning.
>I don't have the original setup, there was only one drive for the
>three motors and the PLC would switch between the motor to be used,
>obviously it could only move from point to point.
>The original drawings show that the motor was run in a series wound
>type of arrangment - for forward operation positive was applied
>through one of the field windings and then through one side of the
>armature and negative went to the other side of the armature. For
>reverse rotation, positive went through the armature (where negative
>was for forward operation)and then out the other side of the
>armature and through the other field winding to negative.
>I hope this makes some kind of sense to you.
>
>

Wow, pretty crazy stuff! Well, it this case, the fields are going to be
low-voltage, high current, so don't apply 50 V to them! It might take 5 V
max to excite the field. A series-wound motor is not very linear, so I
suspect the performance would be pretty rough using the old system.

Jon