Every Mentor MP has a motor field controller as standard that provides excellent field control for the majority of DC motors. However, in the following situations, the optional FXMP25 external field controller is recommended:

• The required field current is greater than that offered by the standard drive, up to 25A. For example, older motors with low field voltages.
• The field is required to be forced down more quickly than is possible with a standard half controlled field bridge. For example, on spindle motors or motors with high field time constants where the field is required to weaken more quickly than the natural time constant of the field winding.
• FXMP25 allows applications to be implemented with simple field current reversal, without armature reversal. For example, applications where a rapid change in torque direction is not required. With the Mentor MP it is possible to implement a four quadrant system with a two quadrant armature converter where a slow change in torque direction can be tolerated.

Easy upgrade

The new FXMP25 replaces our existing FXM5 option. It may also be controlled digitally by a Mentor II, allowing set-up by standard drive parameters. The FXMP25 has the same physical dimensions as the existing FXM5, but extends its current range to 25A.

High current fields

For field currents above 25A, a separate Mentor MP DC drive can be used as a field controller.