OK, this is not the answer, but a little tale about piezo buzzers.

I got a new "stud finder" (for locating wall studs in a building). It
was superb! Got the job done. Three or
four years later, I had occasion to use it again. Worked fine, except the
"buzzer" didn't sound. Tore it down
and found the little devil piezo element. Located a similar Radio Shack
element, and replaced the original.
Still didn't work. SWMBO said "hope you get tired of playing with that noisy
thing"....... HUH?
Well, piezo worked just fine. Ears had aged embarrassingly.

Old Chief Lynn, W7LTQ

wrote in message
...

what is postive and negative on a round buzzer where contacs are an inside
center circle and an outside ring ?

or does positive and negative matter with a piezo buzzer ?