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Topic: Can microphones produce a negative voltage? (Read 2052 times) previous topic - next topic


Can microphones produce a negative voltage?


Yes. Don't connect directly to arduino pins or you may destroy the pin.
Don't PM me for help as I will ignore it.


An audio signal is a varying AC (alternating current) signal.  It alternates between positive & negative at a frequency (related to pitch) and at an amplitude (voltage) related to loudness.  (Microphones typically put-out between 10mV and 100mV depending on the sensitivity of the mic, the loudness, and the distance from the sound source.)

There are microphone boards for the Arduino that amplify the signal to around 1V, and add a 2.5V DC bias to the signal for direct connection to the Arduino.  (i.e. With a 1V peak AC signal on top of a 2.5V signal, the voltage will vary between 1.5 & 3.5V.


Can microphones produce a negative voltage?

Not only can they they always do.

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