Component to produce a nice indicator beep?

[ddbear]

Is there a component on the market that makes a pleasant user confirmation beep? 

For example the same kind of sound you would hear when pressing buttons on a membrane touchpad, so you know when the device registered your button presses?  I did a quick search and found mention of Sonalert products, however when I looked at their products, I don't know which specific ones produce a pleasant momentary tone, vs. the ones that are continuous audible alarm signals.

I have 120VAC or 24VDC available to trigger the button press tone.

[Zero999]

You need a piezo buzzer, with a built-in drive circuit.
https://cpc.farnell.com/unbranded/41-p29l240a/piezo-buzzer-24v-leads/dp/LS01080?mckv=seQZ1zMFY_dc|pcrid|490691434481|kword||match||plid||slid||product|LS01080|pgrid|47130025876|ptaid|pla-371786579278|&CMP=KNC-GUK-CPC-SHOPPING&s_kwcid=AL!5616!3!490691434481!!!network}!371786579278!&gclid=Cj0KCQjwyYKUBhDJARIsAMj9lkHzw43mslM1Q6j62YFHe7TsX_ORK7VbuXzKAFYTAN29xLWWyaW0KM4aArnOEALw_wcB

[ddbear]

How can I figure out which ones will emit a single (pleasant) beep when 24VDC or 120VAC is applied?  (I found some Sonalert models on Mouser that beep once per second, but I don't want it to repeat.)

And I'm not sure which ones have a nice beep that is meant for a keypad indicator type sound, vs. an annoying buzzer beep that is meant as a warning signal.

[MikeK]

A buzzer takes DC and produces a beep.  There are magnetic buzzers and piezo buzzers. I don't consider any of them pleasant.  And the beep would wound as long as the DC is applied.  A transducer is a speaker and needs some AC signal, because it's a speaker.

A momentary beep?  Can't you control it with a uC or a one-shot 555?

[Zero999]

The frequency is given on the data sheet. If you don't know what frequency sounds nice, download a piece of software to play different frequency tones out of a computer sound card or phone's speaker, then you can find a frequency which sounds agreeable.

The product I've linked to produces a continuous tone. If you just want a short beep, then you could make a timer circuit, or use a timer relay to control the buzzer.

[Psi]

The beeper with a built-in drive circuit will give you a frequency in its datasheet.

If you want to know what it will sound like you can use a free audio PC tool like audacity to generate a tone at that frequency with the duration you intend to use and see what it sounds like and if you like it.

Just don't fall into the trap of buying a one without built-in drive.
Some are speakers and need something to generate the sound while others (built-in drive) will produce a tone when you apply 5V/12V or whatever its rated for.

[ddbear]

Good info, thanks!  I wonder if anyone has a "favorite" of these little sound producers for a keypad confirmation tone.  For example on some of the kitchen equipment and air cleaners etc. in our house, the keypad beep sounds definitely more high-end vs. a simple monotonous tone of a certain frequency.  Maybe one way to describe it is a chime/beep hybrid.

[themadhippy]

Alternatively how about one of those greeting card chips that let you record your own sounds

[ddbear]

Alternatively how about one of those greeting card chips that let you record your own sounds

Good idea, although may be a bit overkill if there is a tiny little component that already exists that makes a pleasant chime tone that is produced in the millions for kitchen devices etc.

[Buriedcode]

I vaguely remember building a code lock kit back in the mid 90's.  It used a ASIC to drive a piezo buzzer for the alarm, at 4kHz.  It also gave a brief "beep" (less than 100ms I think) of the same frequency when a key was pressed.  It wasn't particularly loud but wasn't unpleasant.

As previous replies stated, you can get "buzzers" that contain driving electonics to create the tone, so you just apply power and it makes a single tone as long as power is applied.  If you have an arduino you could get plain piezo sounders (these don't have any electronics, just a piezo speaker element) and use Arduinos built in libraries to test tones of various lengths and frequency to hear which one you prefer.

Arduino isn't exactly efficient in its use of hardware, but its great for very quickly (and cheaply) testing ideas like this.

Note almost all piezo buzzers/sounds/elements are round, the square/rectangular buzzers tend to be electromagnetic and work at a lower frequency.  There are round electromagnetic buzzers/sounds, but these work in a similar frequency range to the piezos 2-4kHz.

[james_s]

There are various analog circuits you could make to synthesize a pleasant sounding ding or gong but these days it's really easier to just play a sample from a microcontroller. Years ago I remember seeing Elm Chan released an audio player consisting of nothing more than a ATTINY85, SD card and a speaker. It used the high frequency PWM output as a DAC. For something like you want, you could store the sample in internal ROM. If you already have a microcontroller in your design (suggested by your mention of a keypad) then maybe see if you can use one of the PWM pins to play a sample. I like that someone is at least putting some thought into this, I quite dislike the standard harsh beep sound that most equipment makes.

[MikeK]

You may find that the lower frequences are less objectionable.  I do.  High pitched equipment chirps are awful.  I don't like cardinals' piercing chirps either.

[Geoff-AU]

The easiest thing I've found is to use a regular piezo buzzer and put a small dab of hot glue over the opening.  Piezos are invariably 80dBA or so which is much too loud for my liking, and a bit of hot glue reduces the output significantly.

Our ears have a significant sensitivity peak at 2-4kHz and that's probably the most jarring frequency to pump out at high volume.   But at moderate volume it's fine.

I have a power supply here (Tenma-badged Korad) that makes multiple "sounds" by adding 2 frequencies too - similar to telephone DTMF.  If you use an externally-driven piezo you could play with this too, or just have a microcontroller play out a sample.  Fair bit more work than an internally driven piezo and some hot glue, but if you're really fussy and have hours to devote in search of the perfect beep it's the only way 

[Berni]

The integrated oscillator beepers just constantly make a tone when supplied with power. Much like a mechanical alarm bell does.

The way you could make it do a momentary beep is use a relay to connect a capacitor to the 24V power in idle. Then when you want to beep the capacitor is switched over to power the beeper. Bigger the capacitor the more energy it will bring and so the longer the beep.

As in for a pleasant beep. Its usually the lower frequency tones that beep for a very short duration. I find long high pitched beeps the most annoying.

[AndyC_772]

Tektronix TDS520B component service manual:

https://download.tek.com/manual/070971003.pdf

Page 351, top right corner is the circuit used to produce a polite 'ping' whenever the scope wants attention.

You will still need a couple of other signals to drive it, though - it's not completely self contained. Maybe worth a session with SPICE.

[Haenk]

Besides greeting cards, there are a couple of child toys with integrated sounds, which might provide a broader choice and even allow for different sounds played when pressing different keys.

[Terry Bites]

All piezo buzzer are horrible sounding. The world would be a better place if they'd never been invented!
There are plenty of fools showing how to code your micro to make other sounds on a piezo but never giving any audio examples. Including DH who played a drum track throughout his demo. Whats that about?
Also there are chime prodcuts that don't showcase the actual sound. Who are these idiots??
Get a greting card IC and record any sound you like. Play it back over a phone or tablet speaker. https://www.aliexpress.com/item/32809300438.html