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hi!....... I am narmatha doing my final year phusics.i take E-Scope as my project.I sent a mail to u on 18th feb and u sent a reply.U suggest me to post my project here.I sent another mail on 22nd feb in this site.But u didn't give any reply.I need ur guidance to my project.The following datas are related to my project.the ckt is not able to copy down here(address is noted).see the datas and help me. I got the blinking of LED but not yet heart beat. the sound like urrrrrrrrr....... was heared.please reply me soon.thank u. http://www.electronics-lab.com/projects/science/019/ Home Projects Science related Electronic Stethoscope 2 Electronic Stethoscope 2 author: Audioguru -------------------------------------------------------------------------------- Circuit Description: • U1a operates as a low-noise microphone preamp. Its gain is only about 3.9 because the high output impedance of the drain of the FET inside the electret microphone causes U1a’s effective input resistor to be about 12.2K. C2 has a fairly high value in order to pass very low frequency (about 20 to 30Hz) heartbeat sounds. • U1b operates as a low-noise Sallen and Key, Butterworth low-pass-filter with a cutoff frequency of about 103Hz. R7 and R8 provide a gain of about 1.6 and allow the use of equal values for C3 and C4 but still producing a sharp Butterworth response. The rolloff rate is 12dB/octave. C3 and C4 can be reduced to 4.7nF to increase the cutoff frequency to 1KHz to hear respiratory or mechanical (automobile engine) sounds. • The U4 circuit is optional and has a gain of 71 to drive the bi-colour LED. • U5 is a 1/4W power amplifier IC with built-in biasing and inputs that are referred to ground. It has a gain of 20. It can drive any type of headphones including low impedance (8 ohms) ones. PRIVATEPart Total Qty. Description R1 1 10K 1/4W Resistor R2 1 2.2K 1/4W Resistor R3, R9 0 Not used R4 1 47K 1/4W Resistor R5, R6, R7 3 33K 1/4W Resistor R8 1 56K 1/4W Resistor R10 1 4.7K 1/4W Resistor R11 1 2.2K to 10K audio-taper (logarithmic) volume control R12 1 330K 1/4W Resistor R13, R15, R16 3 1K 1/4W Resistor R14 1 3.9 Ohm 1/4W Resistor C1, C8 2 470uF/16V Electrolytic Capacitor C2 1 4.7uF/16V Electrolytic Capacitor C3, C4 3 0.047uF/50V Metalized plastic-film Capacitor C5 1 0.1uF/50V Ceramic disc Capacitor C6, C7 2 1000uF/16V Electrolytic Capacitor U1 U2, U3 U4 U5 1 0 1 1 TL072 Low-noise, dual opamp Not used 741 opamp LM386 1/4W power amp MIC 1 Two-wire Electret Microphone J1 1 1/8" Stereo Headphones Jack LED 1 Red/green 2-wire LED Batt1, Batt2 2 9V Alkaline Battery SW 1 2-pole, single throw Power Switch Misc. 1 Stethoscope head or jar lid, Rubber Sleeve for microphone. Assembly: 1) Assemble the circuit using Veroboard (stripboard) or a PCB. 2) Use a shielded cable for the microphone as shown on the schematic. 3) Fasten the microphone to the stethoscope head with a rubber isolating sleeve or use a short piece of rubber tubing on its nipple. A thick jar lid can be used as a stethoscope head. The microphone must be spaced away from the skin but the stethoscope head must be pressed to the skin, sealing the microphone from background noises and avoiding acoustical feedback with your headphones. 4) The microphone/stethoscope head must not be moved while listening to heartbeats to avoid friction noises. 5) Protect your hearing. Keep the microphone away from your headphones to avoid acoustical feedback.

  

hi im doing 2 nd year eie,in engineering,at present sem i like to do a mini project,can u able to send your project to my id please my id : arun_4uever@yahoo.co.in

hi, i and my friends are planing to do this project 4 our iii sem please if u can mail me the ckt. diagram. of digital strethescope. it would be of great help. looking 4ward 4 ur co-operation... my mail id is nirav_biomed@yahoo.co.in Quote by --nirav

  

hi im doing 3rd year ece,in engineering,at present sem i want to this project,can u able to send your project to my id please my id : roufulalam@yahoo.com

  

hi i m 2nd electronics student. iwant to do ur project on electronic stethoscope. but here the circuit diagram is not given . so please send me the circuit diagram as soon as possible.... thank you..........

  

Can i get ur project information frm u..Thanq

  

hi, i am praveena,a final b.tech student in ece.i like ur prjt.i want the details of the prjt.so plz send the details to my mail id praveena_ach@yahoo.co.in