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In development... The BT-007

Here’s a little preview of another device in development at PianoPro service. I have finished the first prototypes of a pneumatic operated electrical switch. This is a small block which can convert the small amount of air from a tracker bar hole into an electrical signal.


It is a simple device with a pouch that actuates a microswitch. This microswitch, like all microswitches, has normally open and normally closed contacts, which can be used to control other devices.


It has two ports, a supply port and a control port.  It triggers the switch with as little as 3 inches (water) of vacuum applied. This is a very light duty switch, it needed to be light duty so it could be this sensitive. It can only switch 300mA of current, so it cannot be used to directly control motors or large solenoids.

Vacuum Operated switch

These photos show the switch block assembled and an internal view. There is a bleed cup to ensure fast repetition. The inlet and control ports are standard size for tracker bar tubing. It measures 1 3/4” x 2 3/4”


This is being developed for use with my BT-001 microprocessor based piano control system to signal the end of roll. You may find it useful to develop your own rewind system, or to activate accessories or lights in your piano.

The vacuum switch is close to going into production. The estimated price is $24 plus shipping.