Digital Stethoscope Amplifier Explained

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  • เผยแพร่เมื่อ 22 ม.ค. 2025

ความคิดเห็น • 17

  • @ahmedmoustafa6829
    @ahmedmoustafa6829 7 หลายเดือนก่อน +1

    what is the benefit of the 27pf capacitor ?

    • @STEMprof
      @STEMprof  7 หลายเดือนก่อน

      Good question, it provides more stability while also short very high frequency noise components at the input of the circuit. See more sensor circuit examples in this video collection th-cam.com/play/PLrwXF7N522y7Ut9bm8TXAOhIWqL__FGlj.html. Thanks for watching.

  • @t1d100
    @t1d100 7 หลายเดือนก่อน +3

    You offer an appropriate consideration of the circuit. You explain it very well; kudos! What type of pickup sensor is typically used for this application? If it is some type of audio microphone, then it bears mentioning that the type of microphone used would greatly influence the design of the circuit... For example, an Electret microphone uses a different circuit than a Dynamic microphone. At least that is what I know of audio microphone circuit design. Admittedly, I am no expert. I am not fault finding, here. It is just a thought for anyone considering actually building your design. Thank you so much for sharing your expertise, time and effort to teach us.

    • @STEMprof
      @STEMprof  7 หลายเดือนก่อน +1

      @t1d100 Thank you! My pleasure! You have a good practical point and I appreciate sharing your thoughts. I am assuming an Electret microphone in this Stethoscope Amplifier Circuit example. More Sensors Circuits Videos are posted in th-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html video playlist.

  • @lex4478
    @lex4478 7 หลายเดือนก่อน +3

    This is interesting! Thank you for sharing

    • @STEMprof
      @STEMprof  7 หลายเดือนก่อน +1

      You are welcome! Glad that you liked this Digital Stethoscope Amplifier video. I hope you also like the Electric Guitar Amplifier to XLR Audio Signal th-cam.com/video/X4y8cwZdGEk/w-d-xo.html
      and EKG ECG Amplifier with Right Leg Drive Explained th-cam.com/video/1c7KGXPs4do/w-d-xo.html
      Thank you.

  • @STEMprof
    @STEMprof  7 หลายเดือนก่อน +1

    A Digital Stethoscope Amplifier is explained in this video. Here are a few more Sensors and Circuits videos:
    EKG ECG Amplifier with Right Leg Drive Explained th-cam.com/video/1c7KGXPs4do/w-d-xo.html
    Electric Guitar Amplifier to XLR Audio Signal th-cam.com/video/X4y8cwZdGEk/w-d-xo.html
    Bridge Audio Amplifier Explained th-cam.com/video/EDpu6urAtHA/w-d-xo.html
    Thermocouple Amplifier with Cold Junction Compensation Explained th-cam.com/video/-BsDLBI166U/w-d-xo.html
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    VCA Electronic Gain Control (Part 1): Voltage-Controlled Attenuator Overview th-cam.com/video/cFzYZsPEtP0/w-d-xo.html
    Electronic Gain Control for Op Amp Amplifier th-cam.com/video/NoNgQpbj77Y/w-d-xo.html
    Push-Pull Power Amplifier with Darlington Transistors th-cam.com/video/866MYibo8yE/w-d-xo.html
    Thermometer Circuit Design with Op Amp & BJT transistor th-cam.com/video/55YsraFE0rg/w-d-xo.html
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    See more Sensors & Instrumentation Amplifiers videos in th-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html Circuits playlist.

  • @farahabdullah8698
    @farahabdullah8698 2 หลายเดือนก่อน

    I want to do this circuit in Proteus program can you please tell me the type of the component?

    • @STEMprof
      @STEMprof  2 หลายเดือนก่อน

      Glad that this Digital Stethoscope Amplifier is helpful. I highly recommend using a zero offset low noise CMOS Op Amp for this design. Here are a few related signal conditioning videos:
      EKG ECG Amplifier with Right Leg Drive Explained th-cam.com/video/1c7KGXPs4do/w-d-xo.html
      Electric Guitar Amplifier to XLR Audio Signal th-cam.com/video/X4y8cwZdGEk/w-d-xo.html
      Bridge Audio Amplifier Explained th-cam.com/video/EDpu6urAtHA/w-d-xo.html
      Thermocouple Amplifier with Cold Junction Compensation Explained th-cam.com/video/-BsDLBI166U/w-d-xo.html

  • @ldandco
    @ldandco 7 หลายเดือนก่อน +1

    This is great stuff thank you !!
    Would you consider providing analysis on circuits based on viewers requests ?

    • @STEMprof
      @STEMprof  7 หลายเดือนก่อน +1

      My pleasure! Glad that you like this video. Sure, please share circuits you have in mind, and if it's within my expertise I'll analyze it in a video. The list of existing 200+ circuits videos are posted in th-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html videos playlist. Thanks.

  • @Nigel-g3u
    @Nigel-g3u 3 หลายเดือนก่อน +1

    I really like your content. If only I had this kind of detailed explanation of circuits as a young teenager over 50 years ago, when the only access to information I had was from expensive magazines and the local library reference section, which I could not borrow from and could not take home to study. Only one question for you, why is this called a digital stethoscope amplifier when it is just a simple analog amplifier? Is this just marketing BS by the manufacturer?

    • @STEMprof
      @STEMprof  3 หลายเดือนก่อน

      Glad that you like my videos and circuit design examples. I understand, I had similar limitations back in my early days as well. Regarding your question, this is not a marketing theme. A digital stethoscope requires initial analog signal conditioning (filtering and amplification) before analog to digital conversion for further digital post processing. In case you are interested here are additional practical examples:
      Electric Guitar Amplifier to XLR Audio Signal th-cam.com/video/X4y8cwZdGEk/w-d-xo.html
      Bridge Audio Amplifier Explained th-cam.com/video/EDpu6urAtHA/w-d-xo.html
      Thermocouple Amplifier with Cold Junction Compensation Explained th-cam.com/video/-BsDLBI166U/w-d-xo.html
      Electronic Gain Control for Op Amp Amplifier th-cam.com/video/NoNgQpbj77Y/w-d-xo.html
      VCA Electronic Gain Control (Part 1): Voltage-Controlled Attenuator Overview th-cam.com/video/cFzYZsPEtP0/w-d-xo.html
      I hope these circuit videos are interesting as well.

  • @francescobianchin1331
    @francescobianchin1331 7 หลายเดือนก่อน

    Didnt you miss a pole in the origin somewhere?

    • @STEMprof
      @STEMprof  7 หลายเดือนก่อน

      Thanks for watching and your interest in this circuit. As briefly explained in 3:40 and onward, there are large DC decoupling capacitors at the input of the circuit that effectively kills DC indicating that we dominantly have a zero at origin in the circuit. Here is another audio amplifier example: Electric Guitar Amplifier to XLR Audio Signal th-cam.com/video/X4y8cwZdGEk/w-d-xo.html that might be interesting and helpful.

  • @Chupacabras222
    @Chupacabras222 7 หลายเดือนก่อน +1

    Very nice example. Why are those 2 stages with different upper frequency? Does it have some practical advantage? And what is the 27pF input capacitor for?

    • @STEMprof
      @STEMprof  7 หลายเดือนก่อน +1

      Thank you! Good questions. This design method is not unique. There are many alternative techniques and methods to design these amplifiers. One reason for the higher bandwidth of the second amplifier stage is avoiding further magnitude drop at the upper passband edge of the first stage. As for the 27pf capacitor, it provides more stability while also shorting very high frequency noise components at the input of the circuit. More amplifier circuit videos are posted in th-cam.com/play/PLrwXF7N522y5679YAO-lFrNVYqV9XMNTr.html circuits playlist. I hope you like them as well.