Fwd: Re: [sdiy] Found the Piezo Manufacturer!

[Ian Fritz]

>
>I notice that your circuit  has each switch contact connected to an op amp 
>(+) input with no other connections to those inputs.  This leaves your 
>switch and its wires floating at very high impedance.  My guess is that 
>you are seeing some kind of pickup or leakage effects producing the dc 
>output.  For grins, you might try connecting 1M resistors from the inputs 
>to ground and see whether the circuit still works.  Also, does the circuit 
>work if you press the switch with an insulating rod?
>
>   Ian

Oops, didn't say that quite right. Only one side of the switch is 
floating.  Same concern, though.