John Tuttle is concerned about surges when a switch controlling the
pump motor is opened and then rapidly closed.

This should not be a problem.  A motor draws maximum current when
switched on from a dead standstill.  Once it's up to speed, if you
break the circuit and quickly reclose it before the motor can slow down
much, the switch will handle relatively little current.

Now, it's true that whenever the switch opens, it may arc a little, and
ultimately wear out.  So of course it will wear out sooner if it gets
opened many times during a roll's playing.  This has nothing to do with
the sudden reclosing, though.

There are resistor-capacitor circuits (very simple, one of each) or
Varistors that can be wired across the switch or motor to reduce the
arcing when opening.  Don't use diodes; they work only on DC.

By the way, don't all pump motors have an extra starting winding with a
centrifugal switch, that draws lots of extra current on start-up?  My
D-A grand has that.

 [ The application may be a series-wound 'vacuum cleaner' motor,
 [ which doesn't demand as much starting current.  -- Robbie

Also, the usual pneumatic auto-off system has so much delay in it that
small tears in the roll probably won't jiggle the switch.  You could
slow it down even more by putting a constriction between the
pouch-valve output and the pneumatic that opens the switch.

Hope this helps

Mike Knudsen