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an annoing device(?!)

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bogdanfirst

New Member
well i need a device to make an annoing sound, for more things to ue on:
i sellp very well, and even if o modified a clocl to sound 10 times louder ir is not strong enough to wake me up, so i want to make a douns generator with a very announg sound, wich will make noise for 1 minute.
the other thing i need it for is to prevent people and animals to going in a room, to sound when someone comes there.(i got the triggering device) but the first use is more important.
now, what i thought of is a high frequency sound, with great power, but having a strong sound will wake up people from other rooms, so i want something annoing but not so loud.
i wait for your ideas, on this circuit, and also for other ideas to wake up a sleepy persson.
thanks in advance.
 

Gene

New Member
How 'bout a recordable sound chip on which you have you Mom record, "Hey bogdanfirst, get up NOW!" feed this into a small audio amp and have the feed repeat every 20 seconds until you get out of bed, walk across the room, and shut it off.

Seriously, I have a Radio Shack #273-066 piezo beeper. It beeps - pauses - beeps (on-and-on) with the most irratating noise - you can hear it clearly in 3 rooms. 90dB, 3 - 28 volt, aprox. 12 ma., $5 US. PS - the cats hate this thing.
 

bogdanfirst

New Member
maybe you can give me more details about this buzer. but there is no radio shack here, you might give me some elements of description.
about the annoing chip, i dont think it is such a good idea, but it is a posibility.
 

Gene

New Member
Very similar to Digikey # P9928-ND

http://dkc3.digikey.com/PDF/T031/0881.pdf

requires no external drive circuit - mine is slightly smaller in diameter - the keys are the sound pressure of 90dB, the frequency (not too high, and the pulsing (2 - 3 per second). Sounds like a smoke alarm to me. Hey! That's an idea. How about buying a smoke alarm ($10) and using the buzzer from that. You know, they are designed to wake you up.

I was only kidding about your Mom.
 

bogdanfirst

New Member
this is what i have, from what i remember the big one can give up to 100dB.
but i still need to make a driving circuit. i still think about the frequency. i think i am going to use a circuit with 2 555 timers, one for the sound generator and one for making the beep-beep...effect.
but i think i need a transformer for driving the buzzer wright?
still, i think of some other ideas.
 

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Gene

New Member
Not necessarily. If you go with a 555, it sounds like you are trying to drive a speaker. On the other hand, pezio buzzers come two ways (those that require an external circuit and those that do not).
 

bogdanfirst

New Member
well i just have a simple buzzer, with no feed back. i dont know why but they are hard to find here, seems that nobody needs them.
so the circuit i will have to design must be for a buzzer with no feed back...
 

Sebi

Active Member
Few years ago i`ve tryed out several piezo buzzers as datasheet says: with max.20Vpp. All sounds was above similar. Also tryed several built-in electronic types with better loud. Only one type give 120dB with 12V 130mA: it contains a transformer and supplyed to piezo 300Vpp!
I`ve think this is a spec.type piezo, but when i changed it an other (20Vpp) type, (for fun,i`ve think maybe exploded) it work fine and loud!
 

Gene

New Member
Oh well. Back to the 555 idea. Construct as an astable oscillator, connect pin 3 to a 10 mdf electrolytic (+ to pin 3), the other side of the capacitor goes to a speaker. The other side of the speaker goes to ground. Now, design the R-C pulse circuit on the front side of the 555 to an audio range frequency. You will probably want to replace the speaker with a little audio amp to get really loud. The resistor between pins 6 and 7 of the 555 should be a variable type so you can find the "perfect" pitch.
 

bogdanfirst

New Member
wooooooouuu!
first, i know how to build an oscilator with a 555. my question was mainly what frequency to choose to be very annoing....
i thought that around 10-12KHz, or maybe even up to 12KHz
i have a door alarm, the one that sounds when the door is opened. it uses a buzzer like the one i have and it has got a transformer with a 5R primary and a 120R secondary(connected to the buzzer). it is powered from 3 1.5 V cells and is says it can give 118dB. it will be nice if i could generate the frequency i said with a constant tone with a power of sound of around 100dB
so, thanks since now, but i still want more ideas before i decide upon one idea.
 
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