25 Aug
2014
25 Aug
'14
11:18 a.m.
On Mon, Aug 25, 2014 at 09:47:31AM +0100, Will Godfrey wrote:
On Mon, 25 Aug 2014 08:13:28 +0000
Fons Adriaensen <fons(a)linuxaudio.org> wrote:
The output produced by a piezo is an electric charge proportional
to the mechanical input, so a charge amp is the right way to
capture it, and the standard one for scientific or technical use.
Basically what a charge amp does is to short-circuit the piezo
and integrate the resulting current. And since current * time =
charge, this produces the right output.
What happens with a high-Z input instead is that the capacitance
of the piezo itself plus that of the cable acts as the integrator.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
... or a charge amplifier.
Interesting you mention that. I was wondering if that sort of thing would
work, although I didn't know the name - I had to look it up :)