Ηλεκτρονικο στηθοσκοπιο

[gunsou]

I dont know what kind of performance u want from the circuit but i still belive a buzzer is a poor choice. At least u should use an electret mic. U should also use a gain stage mb with some very low noise opamps and that will allow you to set the sensitivity and then use the power amplification. Take a look at the circuit by Audioguru http://www.electronics-lab.com/proje...019/index.html The same thing can also be done with only transistors if that is what u prefer. U would need a gain of at least 25dB. Audioguru has also added a filter which is a good thing to keep the noise out of ur headphones.

[joke]

Τα fet τι κοστος έχουνε ?

[chip]

Εξαρτάται από τον τύπο... και φυσικά και το κατάστημα
0,2-0,3 ευρώ....