stepper motor in servo loop question

In the vast group memory of CCED, does any one remember if this has been
tried?
Could a VCO be connected between low level analog output from a servo and a
stepper motor driver to allow use of a stepper motor in a servo loop? Some
sort of additional circuit would detect polarity and set the direction
signal appropriately.



It seems so obvious, it must have been done. If it works it could help
revive an old piece of equipment with, you guessed it, steppers and
encoders.



regards-
Elliot B.