>
> There has been a recent discussion on using piezo
> buzzers on logic pins... I was unaware of of the whole
> capacitive loading problem etc. etc., but find it very
> interesting. One thing that I have done to increase the
> output volume of the buzzer moderately is to connect
> both piezo terminals to output bins,  and then to pull
> one pin high whilst pulling the other low (and vice
> versa).  This gives you ~10V accross the buzzer, if your
> pic is running at 5 V.

I did not follow this discussion but I alsowould like to share a good
brainwave I had for this very problem.  I also had a desire once to
increase the volume of a Piezo buzzer and came up with a very
usefull idea for a piezo driver.  The circuit I used had a MAX232
driver chip on board, of which only one Tx and one Rx
driver was used.  So I claimed the remaining Tx driver to drive my Piezo and
"Voila!", all of a sudden I had a 20V swing over the Piezo which was
enough to boost the volume to the required volume.  This made such a
neat little Piezo driver than I will even consider to use it in
other cases where I  also require higher voltage for the Piezo.
Unless someone else can offer a better idea...

Rgds
Werner
--
Werner Terreblanche     http://users.iafrica.com/w/we/wernerte/index.htm
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