Newbie piezo buzzer question

Hi out there,

I'm trying to get a PT-3110W telephone buzzer (rated voltage 5V) to
ring, and I seem to be missing something obvious. It's got +5V coming
in from pin 2 of a 555 (NE555P), which is set up to oscillate
something like an electronic phone ringer. When I hook up another
buzzer there, it bleeps happily and works fine. When I put the
PT-3110W there, it just clicks in time. Here's the kicker: when I put
the buzzer in parallel with the PT-3110W, I can get sound (meaning
actual tones instead of clicks) out of both of them--although the
buzzer is the louder of the two, and the PT makes a weird squelchy
sound at the attack.

Yes, I could just use the buzzer, but it is fairly harsh sounding and
I would like this thing not to sound too much like a smoke detector.
Also, I'm wanting to know what problem I'm running into here. I've
been trying everything I could think of (i.e. checking the resistance
and capacitance of the buzzer and putting similar caps and resistors
in parallel with the PT to try to simulate having the buzzer there,
but that hasn't worked.

Is it possible to put too much current through the PT and wind up with
sound which is outside the range of hearing? Or is this some other
effect?

Any bites?


Thanks in advance,

Torben

 

[Lars Torben Wilson]

On Thu, 04 Dec 2003 23:12:08 GMT, spooge@siffy.com wrote:

ring, and I seem to be missing something obvious. It's got +5V coming
in from pin 2 of a 555 (NE555P), which is set up to oscillate

Hate to follow up to myself, but the astute reader will have noticed
that I should have written 'pin 3' instead of 'pin 2'. The buzzers are
off pin 3, not pin 2.


Torben