[sdiy] Odd keyboard on Ensoniq

[Ken Stone]

More than likely they are little inductors in oscillator circuits, and the
movement of the key will either vary frequency of signal strength. Like
little metal detectors, or the sensors used to detect cars at traffic lights.

Ken

>I pulled it apart and found that the keyboard contact system is rather 
>strange.  Instead of leaf switches or carbon contacts connected to a 
>diode matrix,there are metal plates on the underside of each key and 
>the circuit board has a spiral of traces underneath the plate for each 
>key.  When the key is played it gets closer to, but never touches, the 
>spiral on the contact board.  My only guess is that the spiral is like 
>an inductor and moving the plate closer to or farther away from it 
>induces a small current.
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au  
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