I am exploring the possibility of electrifying players using a method
of vacuum sensing in order to feed a signal to a small programmable 240
VAC inverter, which in turn will regulate the AC motor.  I am trying to
find a component supplier that stocks sensors capable of monitoring
negative air pressure.

The sensor has to be capable of sending an electronic signal (as
opposed to LCD) so that the inverter can raise or lower the power from
the motor to the desired level.  Can anyone suggest a suitable source?

- What would be a sensible range of pressure to monitor?
- What international system or units of pressure measurement should
I use?
- And exactly what should I call such a device?  A pressure/vacuum
sensor transducer/transmitter?

As folks may guess - the field of electronics is not my forte 
Thanks to all in advance.

Roger Waring - The Pianola Workshop
Solihull, United Kingdom
http://www.pianola.co.uk/

 [ You might experiment with an inexpensive motor controller that
 [ has a rotary knob for adjusting the motor speed.  Replace the knob
 [ with a small spool as a windlass.  A sturdy thread attached to the
 [ reservoir and wrapped around the windlass spool and thence to a
 [ tension spring, would then adjust the motor speed in proportion to
 [ the suction of the reservoir.  -- Robbie