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

[cheater cheater]

Yes, and there are hall effect chip sensors, completely integrated!
This is very important, because it simplifies the electronic side of
the thing. As you recall Rainer, the SQ80 has lag (now confirmed by
me) that has to do with the multiplexing of the scanner. I believe
that the chips just output a digital value, which means that every
chip has its own dedicated scanner/counter/whatever.

D.

On Sun, Mar 1, 2009 at 9:35 PM, Rainer Buchty <rainer at buchty.net> wrote:
> 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
>
>