Get PC MIC input

[S.Nirmal]

Hi,

Am trying to read the PC mic input. And i can able to read some waveform with change in amplitude.

But the amplitude is going maximum upto 1v only. Is there any specific reason for that. I want to know whether i can able to measure more than 1v of amplitude?

[LV_Pro]

Microphone signals are usually a pretty low level signal, under 1V, so no, reading voltages directly, above 1v isn't possible, and is likely to damage the mic input. It might be possible to build a calibrated voltage divider with a couple of matched, accurate, resistors. Applying the input to the resistors and measuring the output at their junction will give you a voltage that is their ratio, i.e. if both are the same value, the voltage at the junction is 1/2 the input. A number of considerations need to be dealt with, the primary one being that they have to be accurate resistors, the second being that you want their values to be sufficiently high to not "load down" the signal source. Then you have the issue that microphone inputs are generally "High impedance", basically having a high input resistance as above, to not load down their normal source, a microphone.

Here is an article that discusses some of this.

[S.Nirmal]

Hi,

Thanks for your valuable information.