electronic Stethoscope

stethoscope are not useful only for doctor, but home mechanics, exterminators, spies, and other application. standard stethoscope provide no amplifications, which limit their use. our first exiting project uses the ubiquitous op amp to greatly amplify a standard stethoscope, and the circuit shown also incorporates a low pass filter to remove background noise.

the electronic stethoscope is a fun project with many applications. this project can serve many needs, including detecting noises, vibrations, and leaks by using tubing couple to the microphone. by changing the microphone configuration from a tube to a parabola, you could uses this project to eavesdrop on remote conversations, listen to distance bird or animal calls, or help you to track an animal in the woods.

schematic diagram for electronic stethoscope

part list :
1. R1             10K                              
2. R2,R3,R9  2.2K                            
3. R4             47K                              
4. R5,R6,R7  33K                              
5. R8              56 K                            
6. R10            47 K                            
7. R11            10K potensiometer      
8. R12            330K                            
9. R13            1K
10. R14          1.5 K
11. R15          3.9 ohm

12. C1 470uF 35V
13. C2,C3,C4 0.047 uF 35V
14. C5 0.05 uF
15. C6 10 uF
16. C7 0.01 uF
17. C8 220uF

18. D1 bicolor LED
19. S1,S2 SPDT
20. S3 DPST
21. J1,J2 1/8ich phone jack
22. M1 electret microphone
23. 8 ohm speaker
24. u1,u2,u3,u4, LM741 opamp
25. LM386 power Amplifier