Piezo buzzer - no polarity marks

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
I got this, but saw no polarity markings like my other larger piezo buzzer.

Andy

Piezo Transducer
Electrical Specifications:

    Rated Voltage: 5Vp-p
    Rated Current: 2mA (max)
    Sound Output at 10cm: 85 dBA
    Resonant Frequency: 2.04kHz
    Dimensions: 8.43mm H x 12.1mm diameter
    Number of pins: 2
    Pitch: 6.5mm
    Lead thickness: 0.62mm
    PC mount
    Markings: 12RT04CC

Re: Piezo buzzer - no polarity marks
On 2019-05-20 21:20, AK wrote:
Quoted text here. Click to load it

It expects to be driven by an alternating voltage. If you
connect it to a DC source, a battery for example, it will
just go *tick!*.

Jeroen Belleman

Re: Piezo buzzer - no polarity marks
On Mon, 20 May 2019 12:20:32 -0700 (PDT), AK

Quoted text here. Click to load it

It is not a buzzer, it is a transducer.  

A transducer is a device that can convert (in this case) sound to
electricity or electricity to sound.  To use that as a buzzer you will
need to drive it with an oscillator, at 2.04 kilo hertz and a wave
with a 5 volt peak to peak amplitude (to get the maximum noise out of
it)  

It doesn't have the polarity indicated because it has no polarity.
Think of it as a loudspeaker (another transducer since they can be
used as microphones and convert sound to electricity)

It will work at other frequencies with less volume.  It should click
when you put a battery on the leads, and click again when you reverse
the polarity of the battery.  (it also stores a charge like a
capacitor)

Look up oscillators if you want to use it as a buzzer.  The 555 makes
a dandy oscillator.  

Re: Piezo buzzer - no polarity marks
On Monday, May 20, 2019 at 4:48:52 PM UTC-5, default wrote:
Quoted text here. Click to load it

Ok. I want to replace the current piezo buzzer I have with something that will fit on my breadboard.

It's a pulse type which I do not like.

Andy

Re: Piezo buzzer - no polarity marks
On Mon, 20 May 2019 18:04:36 -0700 (PDT), AK

Quoted text here. Click to load it

I like bells myself.  I cut a chime bar from some hard aluminum alloy
and used a solenoid to pull down on a mallet to strike the bar.  It
sounded bad (with all the mechanical noise the solenoid made) and I
ended up using a 555 as a monostable timer to get just the right
timing on the stroke of the mallet.

I hate piezo buzzers.  Even a speaker driven with a 555 sounds better
to me.


Re: Piezo buzzer - no polarity marks
On Monday, May 20, 2019 at 10:04:35 PM UTC-5, default wrote:
Quoted text here. Click to load it

What specs do I need to look for the speaker?  

My circuit runs from 9 vdc.

Andy

Re: Piezo buzzer - no polarity marks
On Tue, 21 May 2019 19:33:42 -0700 (PDT), AK

Quoted text here. Click to load it
Any small speaker should work.  There's dozens of paper cone speakers
in a 2-3" size that make good annunciators.  If you have a junk radio
you can cannibalize a speaker from it.  I'd use 8 ohms or higher would
be my choice if I was buying one.  You would also need/want an
electrolytic cap of 10-100 uf to use in series with it to keep DC off
the speaker.

http://www.circuitdiagram.org/morse-code-practice-oscillator-using-555.html
http://www.cranburyscouts.org/ElecOsc.htm
http://www.circuitdb.com/?p25%4

Re: Piezo buzzer - no polarity marks
On Wednesday, May 22, 2019 at 5:11:37 AM UTC-5, default wrote:
Quoted text here. Click to load it

Thanks.

Site Timeline