i need some help on finding a suitable eletret microphone circuit to detect 10khz-40khz. I search on the internet. but sadly i dun have a clue what should i find.
So hopefully anyone from this forum can help find for me and paste the circuit diagram or the website URL for me. Thank you very much.
if can, prefer to be a not so complicated circuit and commons components which are widley available. Thank you.
Microphones are for audio which goes as high as 20kHz. They are not spec'd for ultrasonic frequencies.
Here is the frequency response curve of a pretty good electret mic but the trace stops at about 17kHz.
i need some help on finding a suitable eletret microphone circuit to detect 10khz-40khz. I search on the internet. but sadly i dun have a clue what should i find.
Apparently you can use hearing aid microphones for ultrasound. They start to roll-off a 3dB per decade around 15kHz but you can get round this by adding a high-pass filter with the inverse response. Someone I went to college with used a hearing aid microphone in his bat detector project.