Mini buzzer requires AC signal - how to use with DC power

TECHNICAL SUPPORT Sensors & Modules
1

Customer:

I purchased a Mini buzzer from you and want to use it in small projects with DC power. However, I didn’t check the technical specifications before ordering, and I see it requires an AC signal to emit sound, while I currently only use DC power.

I’d like to build something like this: https://www.youtube.com/shorts/CIcAeOqvap8, provided the buzzer produces a strong signal and can be powered by DC.

  1. Do you have buzzers in your product range that work with DC power? If so, please send me links to them.

  2. Does the buzzer intensity depend only on the supply voltage?

  3. I’ve looked at a lot of documentation and videos to learn more about the different types of buzzers, but I clearly need more knowledge. Different designs exist with different applications.

  4. I want to build circuits containing at minimum: a buzzer, LEDs (small and large), and buttons (small and large versions). Do I need a resistor for each of these components, and which values?

  5. Is it possible to control the buzzer volume in such circuits using a 10 kΩ variable resistor?

  6. Can you send me some schematics for these ideas, especially for questions 4 and 5?

Originally submitted via email support on 23 January 2024. Migrated to the forum for community visibility.

2

Soldered Support:

Technically an AC signal is needed, but you can generate an AC signal using a microcontroller (which runs on DC power) with a PWM output on a digital pin.

Here’s our article on working with buzzers: https://soldered.com/hr/learn/buzzer/

Intensity depends on voltage (with a limit beyond which the speaker can be permanently damaged), and the tone frequency depends on the PWM signal frequency sent from an Arduino/Dasduino.

Regarding question 3: yes, there are many variants of the same product because there are small but significant differences in how different users apply them. For a simple project like this, most electronic buzzers should work fine.

Regarding question 4: resistors are needed to limit current flow. For example, with an LED, if connected without a resistor, current will flow from + to - through the LED as if it’s not there - like a short circuit. For connecting the buzzer, check the article I linked above. For LEDs: https://docs.arduino.cc/built-in-examples/basics/Blink/

For buttons: https://docs.arduino.cc/tutorials/generic/digital-input-pullup/
This is the simplest way to connect a button and doesn’t require a resistor.

Regarding question 5: it’s possible to control buzzer volume with a variable resistor. Just connect a 200 ohm resistor in series with it, so that even if you turn it all the way to 0, you still have at least 200 ohms in series. There always needs to be some resistance :slight_smile:

Original message (Croatian)

tehnički, potreban je AC signal, ali AC signal se može dobiti putem mikroupravljača (koji je sam napajan DC napajanjem) koristeći PWM izlaz na digitalnom pinu.

Evo našeg članka o tome kako raditi sa buzzerom: https://soldered.com/hr/learn/buzzer/

Intenzitet ovisi o naponu ( s tim da postoji ograničenje pri kojem se zvučnik može trajno oštetiti) a visina tona ovisi o frekvenciji PWM signala koji se šalje od Arduina/Dasduina.

U vezi 3. pitanja, da, postoji puno varijanta na isti proizvod zato što postoje male ali bitne razlike u primjeni različitih korisnika, ja mislim da za ovako jednostavan projekt, većina tih elektroničkih buzzera će raditi OK.

U vezi 4. pitanja, otpornici su potrebni kako bi ograničili protok struje. Npr, na LE-diodi, ako se ona spoji bez otpornika, struja će teći od + prema - kroz diodu, kao da ne prolazi kroz ništa - to je isto kao da se dogodio kratki spoj. Za spajanje zujalice pogledaj članak koji sam napisao gore, za ledicu: https://docs.arduino.cc/built-in-examples/basics/Blink/

Za button pogledaj: https://docs.arduino.cc/tutorials/generic/digital-input-pullup/
To je mislim najjednostavniji način spajanja buttona, ne zahtjeva otpornik.

U vezi 5. moguće je kontrolirati glasnoću buzzera sa promjenjivim otpornikom, samo spoji uz njega serijski jedan od 200 ohma, tako da čak iako okreneš ovaj na 0, još uvijek ćeš imati barem 200 ohma spojeno serijski. Uvijek mora biti ‘neki’ otpor :slight_smile:

Drago nam je pomoći, nema problema, zato smo tu :slight_smile:

Nadam se da će ti ove informacije i članci koji sam poslao biti korisni.

3

Customer:

I read your advice and checked the websites you sent, but I still have a few questions.

  1. With the buzzers I bought - both leads are the same length, but one side is marked “+”. Does that mean it doesn’t need a longer lead?

  2. These buzzers I bought only produce a single “tick” and no continuous sound when connected to DC voltage (I understand about the microcontroller and PWM, but I’d like to do this without one).

  3. Do you have buzzers in your product range that would let me build these kinds of simple projects: https://www.youtube.com/shorts/CIcAeOqvap8, provided the buzzer works at 5V?

  4. In your previous email you said small buttons don’t need any resistor, but I’m wondering if this larger button: https://soldered.com/hr/proizvod/tipkalo-pushbutton-12mm/ needs a resistor and which one (it’s not stated on your pages)?

  5. For every LED I bought from you - both large and small - is a 200 Ω - 300 Ω resistor always needed regardless of case size - from the tiny 3 mm ones to large ones (I assume the smaller ones at 3 mm need higher resistor values when powered by, say, 5V)?

  6. For potentiometers - when using a resistor with a buzzer - does that resistor go on the center pin or can it go on one of the outer two pins?

4

Soldered Support:

Here are the answers to your questions:

Ah, now I understand - I’m sorry, because in my previous email I misunderstood which buzzer you have. If one side is marked +, then it’s an active buzzer, and it only needs +5V - just that, for proper power - and with that buzzer the volume and tone frequency are fixed. That means a passive buzzer. I tested all the buzzers we have in stock and they are all passive. One product listing says it’s an active buzzer (the one from the video you sent is active), so search for that elsewhere. I think it shouldn’t be hard to find - we just don’t have those types.

The same applies to the larger button - but that’s if you’re using a microcontroller. If you just want to connect battery->button->component, you probably won’t need a resistor. If the component is an LED type (which already requires a resistor anyway) then you’ll have to have a resistor - it all depends on what you’re connecting. 200-300 ohms is fine for those LEDs.

The resistor can go on the center pin - it doesn’t matter where the resistor is in a series circuit. However, for that active piezo I see in the YouTube video it’s connected without any additional resistor, and after a bit more research I found that it’s not necessary to connect resistors to active piezos in that way.

Original message (Croatian)

šaljem odgovore na pitanja:

Aha, sad razumijem, isprike, jer u prošlom mailu sam krivo shvatio koji buzzer imaš. Ako je na jednoj strani označen +, to je onda aktivni buzzer, i samo mu treba +5V - isključivo toliko, da se može dobro napajati - i s tim buzzerom su onda glasnoća i visina zvuka fiksni To je onda pasivna zujalica Isprobao sam sve zujalice koje imamo u skladištu i sve su pasivne, jedan umorivljeni proizvod piše da je aktivna zujalica (ta iz videa koji si posao je aktivna), pa potraži to negdje, mislim da ne bi trebalo biti problem naći, samo mi nemamo takve Za ovo veće tipkalo vrijedi isto - ali to je ako ćeš koristiti mikroupravljač, ako samo želiš spojiti bateriju->tipkalo->komponentu, vjerojatno ti neće trebati otpornik. Ako je komponenta tipa LE-dioda (koja i inače zahtjeva otpornik) onda ćeš morati imati otpornik - sve ovisi o tom što spajaš. 200-300 ohma je skroz OK i za te LEDice Može na središnji pin, nije bitno gdje je otpornik u strujnom krugu koji je spojen serijski. Iako, za taj aktivni piezo vidim da je u youtube videu spojen bez ikakvog dodatnog otpornika i nakon još malo istraživanja vidio sam da nije potrebno na aktivne piezo inače spajati otpornike.

Nadam se da ti ovo pomaže i odgovara na pitanja