LM567

[dananderson99]

I need some help.  I would like to make a eletronic key finder that detects a human whistle.  I would like to use a LM567 tone decoder, a 555 timer to turn the circuit on and off, a mircophone to detected a human whistle, i think i will need a op amp increase the signal going into the op-amp, and some type of buzzer or speaker.  I enjoy playing with electronic but i am far from a engineer.  So i am not sure how to put everything together to get it working correctly.  any help is greatly appercaited. 
Dan

 

[audioguru2]

Hi Dan,
Welcome to our forum. ;D
We have an electronic Keys Finder project in our Projects Section:
http://www.electronics-lab.com/projects/misc/002/index.html
It uses the same piezo transducer for the microphone and beeper. I don't know if anybody made it work, and it might not be possible to whistle at the very high resonant frequency of the piezo transducer.

Your idea of using an LM567 as a tuned filter might work better since it can have a lower frequency than a piezo transducer.
We have a Whisle Responder project that is similar to your idea:
http://www.electronics-lab.com/projects/misc/008/index.html
One of our members had trouble making it work.

My daughter bought a cheap Chinese Keys Finder and asked if I could fix it. It had only a custom-made IC and beeped whenever she spoke and whenever the TV was on. I needed to whistle at a certain pitch to make it work.