[time-nuts] RE; New Wrist watch

Robert LaJeunesse rlajeunesse at sbcglobal.net
Wed Sep 12 12:49:02 UTC 2012


If I recall correctly it was in RF Design magazine many years ago that a 
short article included a schematic for using an ultrasonic sensor and selective 
amplifier (narrowband PLL?) to pick up the 32KHz vibration and convert it to a 
measurable signal. I'd expect a normal microphone to pick up way too much 
extraneous noise such that the 32KHz could not be successfully recovered.
 
Bob L.

________________________________

From: Azelio Boriani azelio.boriani at screen.it

Interesting: trying to "hear" a low frequency crystal using a microphone...
it should be hard: the crystal has to make the case vibrate and this is
energy consuming (unless it resonates). I don't expect to pick up nothing,
except the step motor driving the hands.

On Wed, Sep 12, 2012 at 9:45 AM, Hal Murray <hmurray at megapathdsl.net> wrote:

> Has anybody "listened" to such a watch?  (with a microphone)
>
> Can you hear both the 32KHz basic timekeeping as well as the "tick" when
> the
> second hand takes a step?


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