Author Topic: How can I see sound on an oscilloscope with a microphone?  (Read 27771 times)

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Offline alank2Topic starter

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How can I see sound on an oscilloscope with a microphone?
« on: March 30, 2014, 11:40:26 pm »
Hi Everyone,

I'd like to see sound waves on my DS2072 from a tiny microphone I have.  Do I need to build a circuit to do this?  If so, how?

Thanks,

Alan
 

Offline dc101

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #1 on: March 30, 2014, 11:46:29 pm »
Try running the mic to the input of your computer and then the speaker output to the input of your scope.  Otherwise you could get by with a simple audio amplifier circuit.
 

Online nctnico

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #2 on: March 30, 2014, 11:59:09 pm »
Chances are it is an electret microphone. All that needs is a bias of around 3k Ohm to 5V. The sensitivity will depend on the value of the resistor but 3k is a good start.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline alank2Topic starter

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Offline EEVblog

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #4 on: March 31, 2014, 12:08:31 am »
You don't need anything more than your scope probe:
 

Offline GreyWoolfe

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #5 on: March 31, 2014, 01:15:18 am »
I tested a Kenwood MC-50 desk microphone just using my Hantek DSO.
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Offline mcinque

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #6 on: March 31, 2014, 11:15:11 am »
I guess an electret should work but since AFAIK its sensitivity is not linear you may get wrong readings: I suggest you to use a good dynamic microphone without any other use of circuitry. You should be able to read the AC variations caused by the sound that makes vibrate the microphone's membrane
 

Offline alank2Topic starter

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #7 on: March 31, 2014, 02:35:16 pm »
I did get the electret to work with the circuit I posted, but I'm not so sure how well.

There are a lot of dynamic microphones at amazon for around $10 or so.  They look like they have a 1/4" jack on them.  Will this need an amplifier circuit to work?
 

Offline ju1ce

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #8 on: March 31, 2014, 03:05:34 pm »
If seeing sound is all you want to do, you can also connect a speaker to your oscilloscope and shout at it.
 

Offline Mechatrommer

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #9 on: April 01, 2014, 03:05:15 am »
I'd like to see sound waves on my DS2072 from a tiny microphone I have.  Do I need to build a circuit to do this?  If so, how?
set the DS2072 to mV range and set the sound volume into the mic to the maxed you can, done!
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Offline zapta

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #10 on: April 04, 2014, 02:48:41 pm »
If your probes are x10 don't use them, connects wires directly to the scope.
 

Offline MikeGyver

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Re: How can I see sound on an oscilloscope with a microphone?
« Reply #11 on: April 05, 2014, 04:34:25 am »
Ground the pin of the electret mic with the little ground path to the case, pull up other pin to 5-12volts or whatever with a 4.7-47k resistor, and put a cap to that node, other side of cap is audio out. 3 components to use an electret condenser mic, doesn't get much easier than that.

 


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