Hi everyone

I am suppose to build an electronic stethoscope on "multisim" software
I found the circuit in one of the threads here but I don't know why exactly these stages were used
Can you please tell me why ?!
also, I wanna ask about the input for the circuit. I've been used a microphone but I want to know which frequency best to select that can mimic the heart beat sound?!

This is the circuit I built

thanx in advance

 

Sounds like a school project to me. Hence moved from The Projects Forum to Homework Help.

 

ok thanx

 

Here's a plain English description in a POwerPoint presentation: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0CEAQFjAH&url=https://www.cs.tau.ac.il/~nin/Courses/AdvSem04B/HeartSoundAnalysis.ppt&ei=2YhDVcu2IsLAggSWhoCwDg&usg=AFQjCNE8XkyzC0mbk83dxa6lRbBnAtvgXg

The first and second sounds are different, but mostly, you are looking at relatively low frequency compared to speech.

Here is slide #14 from that source:



John

 

thank you so much john