Can you build your own Electronic Stethoscope? Learn how to build and amplifier circuit

In this activity you will build an electronic stethoscope - ok its basically just an audio amplifier that uses physical amplification. We show you how to test the circuit and build the circuit. At the end we will show the signal on an oscilloscope. The electronic stethoscope electrical schematic will be used to build the first part of the circuit - which is an electret microphone. The microphone will be checked to verify it is working. Next we build the amplifier circuit and check to verify it is working correctly - we briefly how how the whole setup can work with a speaker - but the build for that part is going to be in a second video.
If you are looking for similar equipment to use
Milwaukee (without thermocouple) - amzn.to/37lJBT6
Best Wire Cutters - amzn.to/3xbgf4v
Function generator - amzn.to/38yEuj3
200 MHz Digital Oscilloscope 2 Channels, Grey - amzn.to/3x0KTxu
Timestamps
0:00 Intro
0:27 Electrical Schematic
1:14 Microphone Circuit
2:15 Microphone Circuit Power Check
3:55 Microphone Output
6:12 Amplifier Circuit
7:40 Amplifier Power Check
8:30 Amplifier Output
12:08 Connecting the Circuit
12:00 Measuring Amplified Signal
14:40 Physical Amplification
16:10 Heartbeat Signal
18:10 Optional Speaker
What you will need
• Resistors 1 kOhm and 100 kOhm
• Capacitors 1uF
• Breadboard(s)
• Jumper wires
• Amplifier LF 353 or alternative
• Power supply
• Resistors two 10 kOhm
• Electret Microphone
Optional
• Oscilloscope
• Function Generator
• Transistors and a Speaker if you want to try the schematic shown at the end
Here are some basic refreshers that are helpful to be able to complete this DIY project
Reading Electrical Schematics
• • Collin's Lab: Schematics
• • How to Read a Schematic
Using bread boards
• • Intro to Prototyping B...
Amplifiers
• www.khanacademy.org/science/e...
Gain
• www.allaboutcircuits.com/text...
• www.allaboutcircuits.com/text...
Stay connected!
RUclips Channel - / @htmworkshop
Instagram - / htmworkshop
Twitter - / htmworkshop
Facebook - / htm-workshop-101784815...
Website - HTM-workshop.com

[@pierpa_76pierpaolo]

Interesting but I want to add more sensitivity to the microphone by increasing the dB adjustable by potentiometer. I need it to hear sounds, voices in contact with surfaces (walls, metals, wood, etc). Let me know. Thank you very much.

[@syahirindanial5988]

Hi great video. May I know if you have made an improvement on the circuit to reduce audio issue? and im thinking of upgrading the circuit and use neural network to make a simple diagnosis of diseases. Can you perhaps make a video for it or give any recommendation for the upgrade? Thanks.

[@adithyarajapakshe3791]

Brilliant idea💡 can you please tell wht the exact mic you use for this prototype?

[@HTMWorkshop]

I can't remember the exact component - I believe the diameter may have been around 10 mm.

[@adithyarajapakshe3791]

@@HTMWorkshop Thank you for ur concern!!
S

[@user-qz2jg1vs4g]

Напишите пожалуйста какую микросхему Вы использовали?

[@ivanlim8817]

Hello, may i ask what speaker model are you using?

[@HTMWorkshop]

I believe it was Philmore 4" Square Replacement Speaker with Weatherproof Mylar Cone, 8 Ohm, 5W; TS45

[@fernandohernandeza8850]

What components you used in the driver?

[@HTMWorkshop]

Check the link for the schematic I have used - it needs a couple corrections so check the comments in reddit for the corrections www.reddit.com/r/diyelectronics/comments/opl629/electronic_stethoscope_audio_amplifier_but_we_did/?context=3

[@soriatel]

How to add volume control? how to increase power?
The class b amplifier has zero crossing deformation. how to correct this?

[@HTMWorkshop]

Hmmm, well volume control could probably be added using a potentiometer later in the circuit. I am actually still trying to work out a new circuit for this so that it is more consistent and has less audio issues. Hope I can get it working soon.

[@HTMWorkshop]

More projects are found at HTM-Workshop.com
Note: I used pin 3 as the ground and pin 2 as my incoming signal - the schematic in the beginning shows these two switched.
If you are looking for similar equipment to use
Milwaukee (without thermocouple) - amzn.to/37lJBT6
Best Wire Cutters - amzn.to/3xbgf4v
Function generator - amzn.to/38yEuj3
200 MHz Digital Oscilloscope 2 Channels, Grey - amzn.to/3x0KTxu

[@MajidKhan-hx8uh]

Use hearing aid in sthetoscope

[@FaulddrLaerynn]

you cna wlays look for a think labs 1 or an eco duo, but if you arel ookign for a cheaper solution, i am not really sure other than making an electoprnic stethoscope that also supports your eharing aids, but he stethosocpes i mentioned work for hearing aiods, and also, my girlfirend is also deaf and hard of eharing she uses a think labs 1 , she also has a littmann 3000 and a littmann 3200 stethoscope, hope this helps, :) @@MajidKhan-hx8uh

[@mikefromflorida8357]

Please kilohm is pronounced kilohm, not kil-a-ohm. Yes it matters. It has been around longer than you and I have been alive - show it some respect.