Recent content by f3x

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    Seeking advice for lm386 or similar

    Hi. You probably missunderstoodf what i was saying. 1) I want to do a SPICE simulation of a circuit i have build. 2) This cricuit have a lm386 3) The simulator i have do not have lm386 modeled 4) Searching google for model result in no construtive hint. 5) In fact it only show that alot of ppl...
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    Seeking advice for lm386 or similar

    Hi. I am in the process of making an SPICE simulation of the project Electronic Sthetoscope 2. However i cannot found any model of lm386. Googling at it looks like this is something alot of ppl have dificulty to find. I am wondering if any of you know a chip that have similar utility but...
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    Electronic Stethoscope

    Just seen at digikey that this particular model is in sold in package of 2000+ !! anything else to recomand ?
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    Electronic Stethoscope

    I undestand an opamp can overload... but how can a potentiometer overload ? does it have to do with headphone impedance ? Can i use a preset voltage divider before the lm386 then a potentiometer to reduce a bit the gain ? What are those ? is this a way to setup transistor ? I've seen audio...
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    Electronic Stethoscope

    As you said.... I need an attenuator to reinject chipcorder output to the LM386 I need an attenuator to (optionnally) plug the output of the electronic sthetoscope to computer mic input Both need to be somwhere arround the volume control potentiometter. I somehow fear that there will be too...
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    Electronic Stethoscope

    Yes, i had this question. Can you really plug the output of the lm386 to Microphone input Or you need to go rigth before the volume control to do that ? Your noise sound like aluminium paper being folded near the mic. I hope this isnt the pop and crack that is tipical to opamp audioguru last...
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    Electronic Stethoscope

    from reading the small footnotes and reading other TI datasheet, i am under the impression that 7V means (Vcc+) at 7V and (Vcc-) at ground or Vcc at +- 3.5 v how long does it take to take a 9V battery to 6V ?
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    Electronic Stethoscope

    Hmm, i have one question What do you mean by the TL074 behaving badly when the voltage dropdown to 6V ? Because i have to find some research question on the circuit, and the (Noise/distortion/whatever happen) Vs input voltage seem an interesting subject. Or i can just test experimentally the...
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    Electronic Stethoscope

    Hi ... I have exatcly two guess to make on that topic 1st (less likely ) is the quality of the microphone 2nd ... you have inversed R6 and C4 or C3 and R5 (or R7) making it a highpass filter that cut at 100hz instead of a lowpass filter that keep 0-100hz Pls make sure your capacitor are at the...
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    Electronic Stethoscope

    Well ... i sort of know what i want. I'm building this to identify certain heart song and enphasis them thus a bandpass Oh well i was proud of the opamp i choose as i figured it was good quality etc. I'll wait before doing another digikey order as last one was quite expensive and it's many...
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    Electronic Stethoscope

    I am wrong to beleive that the only place where -9V is needed is at the opamp ? Then the redisign would be in choosing resistance / capacitor values ? In splitted voltage.. the chip i use can work at +- 8V Max recommanded Is there an easy way to get +- 8V from a 9volt battery ? Those two, i...
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    Electronic Stethoscope

    Now, how exatly i assure that the input bias is correctly configured ? If i have ground and 9V... the input bias is 4.5V ? meaning that i need to keep at least 4.5volt anywhere in the circuit ? If so ... i may switch to your positive / negative power source. Sorry to be a noob but what exatly...
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    Electronic Stethoscope

    Thanks you, well i'll see for my quad opamp ... i may change it latter. Is the noise twice as it's a quad versus a double ? If not do you have any quad you recommand ? What do you mean exactly by inbut bias ? I see that you are using some electrolytic capacitor in your circuit. Aren't they...
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    Electronic Stethoscope

    Hi everyone Tanks for the interesting reading (20 pages is A lot ! ) Like many others I have, chosen this stethoscope as a school project. My particular study in the team is about different heart frequency, and thus i need to have multiple optional filters... e.g. No filter, low pass, band...
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