OT: Smallest possible beep...

[Hal]

im wondering how I can make a small buzzer - as small as possible.  Although this will be powered by a 9v battery, size matters.  I dont wanna go much bigger than the battery here.  I have old modem speakers that i hope to use.  I also know how hte current will be triggered.  How can i make one of these buzz?  Are there "buzzers" that i can buy, that i don't need to use external electronics, just supply a current to the buzzer?  I know i can always generate a sine wave, and put this to a speaker, but the part count seems high.  I don't care what the sound is - beep, buzz, whatever.

[niftydog]

You need a piezo buzzer and a 555 timer osclillating at say 1kHz.

[Hal]

i think im answering my own question, but i ordered a sample of a buzzer from http://www.avxcorp.com/

that might work...who knows lol

maybe they won't reject my request for 1 item.  I haven't been havein' much luck lately, though...except TI.  They rock :-D

[smoguzbenjamin]

Yeah TI's got a customer in me Their sample service is great... If there's no import taxes connected to it I'm going to collect so many opamps that I'm blue in the face...

[Ge_Whiz]

You can buy piezo buzzers with the oscillator circuits built in, usually about 25mm diameter, but I've seen 'em down to 15mm.

[The Tone God]

beep beep beep beep beep beep beep beep

Thats as small as I can get it. Sorry. I'm in a silly mood.

Seriously there are smaller piezo crystals. Even flat ones that are ment for small spaces like watches or beeping when you press buttons like for appliences. Some don't require external parts. If they need an oscilator you can make one out of a single transistor and a few parts. It all depends on what freq you want and how much power you want it put out.

Andrew

[Johan]

type in "buzzer" in the searchwindow here
http://www.elfa.se/en/

the first one that comes up costs less than 2 euro/dollars and runs on 1,5volts...

Johan