Looking for a small sounder.

[Scarr]

Hi,

Does anyone know where to get a small sounder like the ones in pagers?

Thx

Steve

 

[HarveyH42]

https://www.goldmine-elec-products.com/products.asp?dept=1108
Maybe one of these...

 

[Scarr]

Thanks HarveyH42

So they are just piezo transducers are they?

thx

 

[xxxxxxxxxxxxxx]

yep- in a little resonount housing. If you have some old musical christmas cards, then their sounder works ok, but sometimes not as loud. If you do just use the piezo element, be sure to attach it to something so it is louder.

 

[Scarr]

Driver circuit

Hi again,

OK, found loads of these on the web and in RS / Farnell

Now I have been looking for a driver IC one that will keep it easy for me to get a lage voltage swing with least components. I have found a few but cannot find where to buy them or there are in packages that are hard to solder. I am happt with SMT with legs but not BGA types

Max4410 (no parts with legs on avaliable)
MAS6240 (can't find where to get these)

Anyone help?

 

[Hero999]

Why not use a piezo buzzer with a built in driver so you don't need an IC?

If you need different frequency tones then use an astable 555 timer.

 

[xxxxxxxxxxxxxx]

I agree with Hero999, it would be easier using a 555 timer for the sound and even easier using a piezo with built in driver.

 

[HarveyH42]

Search this forum, remember that canadian posted a simple 2 transistor push-pull type driver a couple of times. You most likely have a couple of transistors laying around. Tells us what kind of sound signal you are looking for, perhaps we could provide more help.

 

[Scarr]

Driver

Yes, sorry I should have been more informative, I want to make lots of sounds just like a pager, beeps, twirps, pulses so a buzzer will not work (will it?)

I want to supply TTL type pulses via a atmega128 and create a variety of sounds. Might even use the built in D/A instead of TTL pin if I get round to it.

Thx

 

[HarveyH42]

I used one once directly from an output pin on a tiny13. Loud enough, but not ear-piercingly. I was trying for a siren... A simple transister amp should be more then enough.

This isn't the one I was thinking of, but similar...
https://www.electro-tech-online.com/attachments/push-pull-piezo-driver-png.11849/

 

[Scarr]

Driver

Thanks HarveyH42 but I really want a single IC solution if there is not one avalible then the simplest but loudest solution (running from 3.3 v) fully explained as I'm a newbie please.

thx

 

[Scarr]

Anybody?

Can anybody help?

 

[Hero999]

What do you mean by twirps?

How loud do you want it to be?

If you want a pulsed tone, you can buy buzzers that will do that or you could buy a simple buzzer and add a 555 timer, the TS555 will work down to 2V which would settle your 3.3V requirement.

How loud do you want it to be?

At 3.3V you're not going to get a loud sound, you could add a 8hm: to 1khm: audio transformer to make your piezo look like an 8hm: load but the current provided my CMOS devices working at only 3.3V is very small and won't be sufficient to give you loads of volume.

 

[HarveyH42]

The piezo element is a crystaline layer, same stuff they use in lighters, or on ignitors for gas stoves and grills. When you stress (bend) the crystal, it produces a spark. When you apply a voltage, the crystal bends. You wouldn't expect much of a spark from 3.3 volts...

 

[Hero999]

Although what you say is true you've neglected to mention that lighters use a long cylinder of piezo crystal and piezo transducers use a thin wafer of piezo crystal. The long cylinder will give a high voltage and lower current and the wafer will give a low voltage and a higher current. An igniter element will be rated to 5kV and a transducer element might be rated to 30V.

 

[Scarr]

Like a pager

OK, I think I need to clarify things again.

I want to reproduce exactly what a common (CST type) pager does, now I may be wrong but I thought it has a small piezo sounder in there and it was driven from 1.5v (obviously boosted, but to what level I do not know)

I found lots of piezo sounders and all I need now is the driver, I'm no electronics wizard (very part time newbie) so making my own was out of the question, so I looked for drivers IC's, found some but cannot get supply of these.

So, I came here hoping that this had been done before and to find a fully explained schematic of a simple (low part count) driver circuit or better still a IC that does it all as the sounder is only one small part of my project.

Hope this clears things up and helps you help me

Thx again for help so far