# convert buzzer to digital audio

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#### mark2326l

##### New Member
I have a TMB12A05 buzzer on a board. I looked it up and it takes 5v to energize it.
I am wanting to replace the buzzer with some sort of sound chip so I can pipe the sound through a headset.
Can someone point me in the right direction?
Thanks

#### dknguyen

##### Well-Known Member
Removed. Misinterpreted the request.

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#### audioguru

##### Well-Known Member
I think he wants to hear the buzzer buzz in his headset, not to hear speech or music.
Then whatever activates the buzzer with 5V can power an oscillating opamp or something that can drive the headset.

#### dknguyen

##### Well-Known Member
I think he wants to hear the buzzer buzz in his headset, not to hear speech or music.
Then whatever activates the buzzer with 5V can power an oscillating opamp or something that can drive the headset.
Ohhhh, I see. I guess you would just desolder the buzzer two pins and solder in two wires connected to a cable with a 3.5mm audio jack. Might need to stick an attenuator if it's too loud or an amplifier if it's too quiet, but it's simple enough to just do this first and check. Don't be wearing your headphones when you first test it.

I'm unsure how friendly a piezo buzzer, which is probably be run off a DC square wave, would play with your head phones. You might want to stick a large DC-blocking capacitor (47 or 100uF maybe) in between one of the wires so your headphones get an AC square wave. Make sure you get the polarity the right way or the cap will explode.

#### mark2326l

##### New Member
My situation..
I have a "backup beeper" that increases the sound interval frequency the closer the sensor gets to something.
I want to use this in my airplane, 'on landing' the closer I get to the ground the faster the beeps. It's very noisy without headsets, and wouldn't be able to hear the current buzzer.
As far as what type of sound chip, a beep or buzz. I just cannot seem to find anything close searching "Sound output chip" among other things. What I do find are small boards with buzzer like mine soldered to them.
So what I need is something that creates a digital sound I can send to my intercom.

#### dknguyen

##### Well-Known Member
My situation..
I have a "backup beeper" that increases the sound interval frequency the closer the sensor gets to something.
I want to use this in my airplane, 'on landing' the closer I get to the ground the faster the beeps. It's very noisy without headsets, and wouldn't be able to hear the current buzzer.
As far as what type of sound chip, a beep or buzz. I just cannot seem to find anything close searching "Sound output chip" among other things. What I do find are small boards with buzzer like mine soldered to them.
So what I need is something that creates a digital sound I can send to my intercom.
Suitability of the backup buzzer for airplane ground warning aside...
That's because you don't need a sound output chip. Just remove the buzzer from the board and wire headphones in place of the buzzer's two connections. If it's a huge buzzer like a truck then stick a resistor inline (maybe even a potentiometer so you can adjust volume) with the headphones so you don't blow your eardrums out, and don't do the first test wearing your headphones. Also, don't forget the inline DC-blocking capacitor mentioned earlier.

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#### MikeMl

##### Well-Known Member
Other option is to leave the buzzer in place, put a 1-5Ω resistor in series with the ground side, and use an audio-coupling capacitor to couple the audio to the headset circuit... You can add a resistor in series with the coupling capacitor so that the buzzer doesn't load down the normal headset audio (much). You will have to play with the resistor values to make the audio levels as needed...

Like this:

I have done similar to make a gear-up-warning buzzer audible in aircraft headsets...

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#### mark2326l

##### New Member
OK I'll give these suggestions a try.
Thanks alot guys!

#### cowboybob

##### Well-Known Member
Trust the guy with an airplane... .

#### mark2326l

##### New Member
Suitability of the backup buzzer for airplane ground warning aside...
Agreed, this is not meant for "ground warning", rather to help my friends while teaching them how to land get a better feel for their depth perception.

#### audioguru

##### Well-Known Member
The datasheet for the beeper shows that it has a built in oscillator and it draws about 30mA from 5VDC. 30mA x 5 ohms= 150mV which will not be loud enough in 8 ohms to 32 ohms headphones. An amplifier is needed.
Then use two resistors and a capacitor to feed into the headphones. I bet it will produce a loud POP when each beep starts and again when each beep ends.

#### audioguru

##### Well-Known Member
The beeper is supposed to say, "Pull Up Terrain, Pull Up Terrain" like they do on the TV show Mayday.

#### dknguyen

##### Well-Known Member
The beeper is supposed to say, "Pull Up Terrain, Pull Up Terrain" like they do on the TV show Mayday.
Well that's just silly. The last thing you want the terrain to do is pull-up.

#### MikeMl

##### Well-Known Member
The beeper is supposed to say, "Pull Up Terrain, Pull Up Terrain" like they do on the TV show Mayday.
That is exactly what the b1tch-in-the-box tells me every time I purposely fly too close to a mountain top. She gets downright insistent on the second and third warning... She says "obstacle ahead" if I fly too close to a radio tower...

#### mark2326l

##### New Member
I found what I was looking for...
Snap Circuits
audioguru's post made me think it would be funny to take my sons "Snap Circuits" voice recording chip and say Oh $h#t, Oh$h#t.
That reminded me he has several chips that make tones, beeps, and alarm sounds. I had what I needed all along.
Tonight I'll be tearing my kid's toy apart

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