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Topic: Power requirements for mic circuit (Read 242 times) previous topic - next topic

tjones9163

Aug 19, 2019, 01:33 am Last Edit: Aug 19, 2019, 01:36 am by tjones9163
Hello, below I will have a picture of a condenser microphone circuit. The circuit works fine with 5v.
I am just wondering if it is safe to power with 9v battery?
I know the Lm386 can handle the voltage, I am just worried about the audio input jack!
Or is it not receiving power through the jack and just supplying the signal?

SteveMann

Google LM386 Datasheet.
The LM386N-1, -3, LM386M-1, LM386MM-1 are rated to operate between 4- to 12-Volts.
So, yes.


tjones9163

Google LM386 Datasheet.
The LM386N-1, -3, LM386M-1, LM386MM-1 are rated to operate between 4- to 12-Volts.
So, yes.


Thank you for the response, but i stated in my op that i know the lm386 can handle it, if you read above.
Is ok for my phone that is connected through the audio jack.

wolframore

#3
Aug 19, 2019, 03:38 pm Last Edit: Aug 19, 2019, 03:42 pm by wolframore
Follow the signal flow for opamp.  Think this through... ask yourself...what happens at the input when there is no signal?  What happens at the input when the signal is high... I don't understand the connection to an Arduino.
Bad Boys Rate Our Young Girls But Violet Goes willingly - Get Some Now :) - ELI the ICE man

DVDdoug

I assume you're connecting the phone's headphone-output?

Yes, it's signal-only.  You won't damage your phone.

That's a mono amplifier so you'll only get the left or right signal unless you build two (not great for music).   ...And, don't "short" the phone's left & right outputs together.


Quote
Hello, below I will have a picture of a condenser microphone circuit.
Hmmmm…..   There's no power for the condenser mic and the gain is too low for a microphone signal.



tjones9163

#5
Aug 20, 2019, 12:08 am Last Edit: Aug 20, 2019, 12:09 am by tjones9163
I assume you're connecting the phone's headphone-output?

Yes, it's signal-only.  You won't damage your phone.

That's a mono amplifier so you'll only get the left or right signal unless you build two (not great for music).   ...And, don't "short" the phone's left & right outputs together.

Hmmmm…..   There's no power for the condenser mic and the gain is too low for a microphone signal.



Im sorry below is the condensor mic circuit that i got confused with the last post.
Do you see anything wrong with this circuit?

SteveMann

A condenser microphone normally needs a bias to operate because it has an FET pre-amp built in.  The voltage is not critical.  In professional sound systems, the mixer board will provide this bias in the form of "phantom power", typically 48-Volts.

A dynamic microphone generates power relative to the dynamic pressure of the sound striking it, and it needs no bias voltage.

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