Piezo beeper - which one?

[futz]

I'm shopping for a handful of piezo beepers at Digikey. But they have hundreds of variations and I'm not sure what to get. What I'm looking for is something like a computer mainboard style piezo. I have no idea about what resonant frequency to get, much less all the other variations there are. I want to use these with PICs and must build one replacement mainboard beeper for a friend (I stole his and put it in a customer's computer ).

Anybody have a part number?

 

[ericgibbs]

I'm shopping for a handful of piezo beepers at Digikey. But they have hundreds of variations and I'm not sure what to get. What I'm looking for is something like a computer mainboard style piezo. I have no idea about what resonant frequency to get, much less all the other variations there are. I want to use these with PICs and must build one replacement mainboard beeper for a friend (I stole his and put it in a customer's computer ).

Anybody have a part number?

hi futz,
Most piezo beepers are around the 3KHz range.

I like and use the supply polarised version, works from +3V thru about +12V, fairly high resistance so that the loading on the TTL/PIC pin is light.

They are nominally about 80dB, about 2cms in dia, black plastic body.

Not knowing you suppliers in Canada I cant suggest anyone other than Digikey.

If it helps I could search the UK sources and post some pictures/links.

EDIT: link for Farnell piezo sounders,
Piezo | Farnell UK

 

[audioguru]

Digikey delivers to Canada the next morning if you order before 8:00PM.

A piezo beeper has a built-in oscillator that operates at the loudest resonant frequency.
A piezo transducer is a speaker that needs an amplifier to drive it at its resonant frequency.

 

[Valence_4]

You must be sure of the piezo you need. There are two kinds of piezos on the market:

1 - The piezo oscillator. You simply supply it with DC and it oscillates by itself and

2 - The piezo transducer. You have to feed it with the actual square/sinewave to make it sound. Often, the transducers have three legs. Drive Feedback and Ground. The Drive pin is connected to the largest portion of the piezo crystal and is used to make the piezo sound. The Feedback pin is connected to a small portion of the piezo crystal. It is used for feedback in an oscillator circuit. Ground is common. those are mainly used to build piezo oscillators.

Hope that helps !

 

[futz]

Digikey delivers to Canada the next morning if you order before 8:00PM.

Yes, I know. That's why I said this

I'm shopping for a handful of piezo beepers at Digikey.

I order from Digikey fairly often. Expensive, but fast and convenient. Worth the extra $$ most times.

A piezo beeper has a built-in oscillator that operates at the loudest resonant frequency.
A piezo transducer is a speaker that needs an amplifier to drive it at its resonant frequency.

Ya, it's a transducer I'm looking for. It doesn't really need any amp though. I just hook em to a PIC output and buzz that pin at different rates till I find what I'm looking for. Doesn't need to be screamin loud. A good beep is fine.

 

[futz]

2 - The piezo transducer. You have to feed it with the actual square/sinewave to make it sound.

That's the type I want.

Often, the transducers have three legs. Drive Feedback and Ground.

Really!?!? I've never seen a three leg one (yet). Only the two leggers. Two legs is what I want.

Hope that helps !

Yup. Thanks. I'm getting closer, but I still don't really know which one(s) to pick out of Digikey's myriad of different piezo's. I might just do a shotgun order - get one each of a bunch of different ones and see which works out best for next order.