Buzzers - Page 1
Forum section: electronics / beginners

author: rafalpilat0077
author_rank: Contributor
timestamp: January 03, 2014, 02:47:05 pm
content: So , recently i bought these buzzers:http://www.digikey.com/product-detail/en/PS1240P02CT3/445-5229-1-ND/2179635I connected them to a 5v battere, and what happened? Nothing.These buzzers are rated for max 30v. So 5v might not be enought but it should make some sound at least. Right?Later i looked at the data sheet and i found something wierd:Does that mean i need to give it a square/rectangular wave???I tought ill just connect a few volts and it will buzz.But it dosent.What should i do?

author: alxnik
author_rank: Regular Contributor
timestamp: January 03, 2014, 02:51:56 pm
content: There are buzzers which need DC and have an internal oscillator and (most commonly known as) piezo elements which need external square wave. I'm guessing that yours is a piezo.You can drive the thing with a 555 or even a transistor based astable multivibrator (or a micro...), so it's not much. Or you can just scrap it and buy an integrated buzzer

author: rafalpilat0077
author_rank: Contributor
timestamp: January 03, 2014, 02:55:56 pm
content: So what is the 2khz frequency about? Dosent the sound depend on what frequency i put in?

author: alxnik
author_rank: Regular Contributor
timestamp: January 03, 2014, 03:09:36 pm
content: This is the resonant frequency of the piezo. The frequency that makes it sound the loudest. You don't have to drive it at that frequency, I actually like to drive them at different frequencies for different events, but you get the idea.

author: kolonelkadat
author_rank: Regular Contributor
timestamp: January 03, 2014, 03:14:18 pm
content: page 7 has a circuit diagramhttp://www.tdk.co.jp/tefe02/ef532_ps.pdfmake it to get sound out

author: alxnik
author_rank: Regular Contributor
timestamp: January 03, 2014, 03:29:00 pm
content: Quote from: kolonelkadat on January 03, 2014, 03:14:18 pmThis is a driving/amplifing circuit, it won't make any sound by itself. You still need a waveform generator

author: rafalpilat0077
author_rank: Contributor
timestamp: January 03, 2014, 03:30:27 pm
content: I think i will use a 555 timer. Also, will 5v be enough?

author: Unknown
author_rank: Unknown
timestamp: January 03, 2014, 03:30:56 pm
content: Quote from: From the Digikey page

author: con-f-use
author_rank: Unknown
timestamp: January 03, 2014, 03:32:33 pm
content: Quote from: rafalpilat0077 on January 03, 2014, 03:30:27 pmFive Volt will be enough to hear something just right. Might not be enough to be louder than an all-out air condition.In case you use a micro controller anyway, you can just .while(1) { buzzerPin = HIGH; wait_ms(1); buzzerPin = LOW; }.Quote from: kolonelkadat on January 03, 2014, 03:14:18 pmMinor typo.

author: rafalpilat0077
author_rank: Contributor
timestamp: January 03, 2014, 03:35:25 pm
content: So , isnt this just a tiny speaker?

author: con-f-use
author_rank: Unknown
timestamp: January 03, 2014, 03:39:15 pm
content: Quote from: rafalpilat0077 on January 03, 2014, 03:35:25 pmA tiny speaker, that is loudest at it's resonant frequency and has some other limitations, yes.

author: alxnik
author_rank: Regular Contributor
timestamp: January 03, 2014, 03:40:48 pm
content: Quote from: rafalpilat0077 on January 03, 2014, 03:30:27 pm5v will make a sound but other than that, it depends on your use. I found that for a buzzer inside an aluminium case (not sealed), I needed around 12v to make it sound like a buzzer and not like a fart. If it will be placed to a clear area with line of "hearing", 5v should be enough. However if you want to build a smoke detector, I would say stay close to 30v.Quote from: rafalpilat0077 on January 03, 2014, 03:35:25 pmYes and no. Speakers generally have a (more or less) flat response over a range of frequencies. These are made to output a tone. You can probably drive them with music, but you would probably laugh at the result

author: rafalpilat0077
author_rank: Contributor
timestamp: January 03, 2014, 03:44:20 pm
content: Quote from: alxnik on January 03, 2014, 03:40:48 pmHmm....Making it sound like a fart might be usefull.

author: rafalpilat0077
author_rank: Contributor
timestamp: January 03, 2014, 03:48:52 pm
content: Also , are those buzzers polarised?

author: Bored@Work
author_rank: Super Contributor
timestamp: January 03, 2014, 04:53:03 pm
content: Quote from: alxnik on January 03, 2014, 03:40:48 pmIt is actually done in stuff like music playing greeting cards or other gadgets playing Mull of Kintyre or For Elise until you just want to vomit all over.

author: kolonelkadat
author_rank: Regular Contributor
timestamp: January 03, 2014, 08:31:39 pm
content: Quote from: alxnik on January 03, 2014, 03:29:00 pmexactly, as is illustrated in the diagram by the square wave "blackbox" that is labeled "cmos, etc". where "etc" could be a 555 sig gen or whatever.Or am I wrong? I found that I really prefer software, so thats my fulltime gig. hardware is just a hobby. That said, I remember in school the highlighted symbol in figure 1 was a "black box". It was used when didnt really matter what was in there, as its exact structure wasnt pertinent to the rest of the system. It could be a mouse on a wheel, as long as the input and output were right. So when I saw the symbol in fig.1, I took it to mean "just put whatever here, as long as the output is wavy." Please let me know if im wrong so i dont make this mistake in the future.fig. 1

author: Unknown
author_rank: Unknown
timestamp: January 03, 2014, 08:34:04 pm
content: Quote from: kolonelkadat on January 03, 2014, 08:31:39 pmSounds about right. The mouse on wheel analogy should be in an FAQ.

author: Zero999
author_rank: Super Contributor
timestamp: January 03, 2014, 10:44:00 pm
content: A 555 timer will work but there are better ways to do this.A 74HC14 Schmitt trigger IC is much simpler and more effective.