Bruce,

Have you looked at it with a scope?  You'll see what they're talking
about.

Don

Bruce Cannon wrote:
>
> Hello all:
> I've been developing a device which includes a piezo element driven
> differentially by two IO lines, no other components.  It works great and
> draws very little power for so much sound.  Too easy, I wonder?  I've looked
> over past PICLIST discussions of driving piezo elements with the PIC (and
> have searched the web for other info as well to no avail), and have seen
> mention of a series resistor, annd occasionally external protection diodes.
> 1. Can anyone give me a nutshell explanation of why these elements might be
> neccessary?  I understand that there is an average current at the given
> frequency, but is there also an instantaneous (or do I mean periodic?
> inrush?) current and/or voltage which I must consider as well (and which is
> dangerously higher)?
> 2. Can anyone recommend a source for additional reading to help reduce my
> ignorance?
> Thanks,
>
> Bruce Cannon            Style Management Systems
> bcannon@jps.net         http://www.jps.net/bcannon
> (510) 787-6870          1228 Ceres ST Crockett CA 94525
>
> Remember: electronics is changing your world...for good!