Timed fades circuit for stage lighting desk

I’m building a stage lighting desk for an amateur dramatics group and need a timed fade-up and timed fade-down circuit to achieve the following:
-adjustable timed fade up from 0 to 10v over 0 to 10 minutes, initiated by rapid fade up of a slider pot
-adjustable timed fade down from 10 to 0v over 0 to 10 minutes, initiated by rapid fade down of a slider pot

Can anyone help please?

This circuit should work. When the slider is at the center, the time is very long, it may be dificult to determing a setting for 10 minutes. zero to 10 minutes is an infinite ratio, so that is not possible. The minimum time is about 50 milliseconds.

Timed fader

Russell

Many thanks for the circuit. I will email separately futher comments.

CPnick