Warning about that sound sensor module

I just wanted to issue a warning about this kind of sound sensor module, which can be found from various sources in the Internet:

http://www.vetco.net/catalog/images/VUPN6319-1.jpg
(link provided only for the module's picture, not to tackle that vendor)

I purchased two pieces and have analysed the schematic.
One could think, the chip on-board could have been an Op amp, and the module would consist of an amplifier and comparator, so it has a digital and analogue output.

What a mistake!

The chip on-board is a pure comparator, providing comparison directly from the microphone signal towards a voltage divider at a few millivolts level only.
There is absolutely no amplification provided and the "analogue output" is in fact directly picked from the microphone, adding all perturbations backwards into the microphone signal to the comparator.

So that module could merely be described as a random signal generator, optionally a temperature switch, since the microphone FET is DC coupled to the comparator. It is also a radiofrequency harvester since there is absolutely no capacitor to reduce interferences.

I could have thrown the few bucks directly into the waste bin...

I believe that this sensor is much like a clap sensor, it can detect only loud noise.

zoomx:
I believe that this sensor is much like a clap sensor, it can detect only loud noise.

Oh no, it can detect much more:

-Temperature
-Wifi signals
-Mobile phone HF
-your Karma
-telluric activity
-and thousand other parameters, including, maybe, to some undefined extend, sound...

:wink:

MiFi:
-your Karma

:grinning:

The module is a "sound sensor", it gives an output when it senses sound.

Appears to be as described.

Weedpharma