Yamaha BC2 Breath Controller

Pictures and Description

Rubber ‘bladder’ connected to the breath input with a magnet in the center which ‘drives’ the hall effect sensor IC3 . In other words, the BC2 does not use a pressure sensor, but a hall-effect sensor, whose output is dependent on the strength of the magnetic field. This keeps moisture from the breath from affecting the sensor. The ‘bladder’ is sealed.

This is the other side of the bladder. It is sealed by the bottom of the BC2 case.

Component Side of Yamaha BC2 Breath controller. IC3 is in the very center and is a hall effect sensor. 

IMG 1731

This is the inside of the headpiece showing where the PCB sits. The teardrop shaped feature seals the rubber bladder while the “+”  in the center preloads the rubber bladder so it sits close to the hall effect sensor on the PCB. 

The “top side” of the PCB. Output cable is on the lower right corner.

It is not well documented, but the Tip (red wire) of the stereo plug is ground, the Sleeve (black wire) is +Volts and the Ring (white wire) is the output voltage.