[sdiy] Ensoniq patent, was: distance meter for keyboard, was: Where to get special white keys?

[Rainer Buchty]

On Sun, 1 Mar 2009, cheater cheater wrote:

> come on, 100 keys * 3 dollars = 300 dollars
>
> certainly not a big amount by the standard of making the best keyboard
> in the universe

To my understanding it's much cheaper -- the key is the core of an open 
coil, so by moving the key that alters the inductivity and therefore 
tunes an oscillator which frequency is then measured.

http://itec.uka.de/~buchty/ensoniq/schematics/sq80/sq80-kbd-lower.jpg
http://itec.uka.de/~buchty/ensoniq/schematics/sq80/sq80-kbd-upper.jpg
http://itec.uka.de/~buchty/ensoniq/schematics/sq80/sq80-kpc.jpg

Rainer