#1851

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КОМЕНТАРІ • 38

  • @JoeGoesXtreme
    @JoeGoesXtreme Місяць тому +19

    Looks great. It might be interesting to pass a sine wave and measure THD at the output and compare it with THD at the input.

    • @cmuller1441
      @cmuller1441 Місяць тому +1

      Yes and this circuit is not designed to pass high frequencies so it's not a surprise that the square wave has overshoot.
      He should also do a bode plot of the frequency response.

    • @AdmiralQuality
      @AdmiralQuality Місяць тому

      @@cmuller1441 I'd think we should see Gibb's phenomena then, which this doesn't look like.

  • @danielatbasementtech
    @danielatbasementtech Місяць тому +3

    Really cool project ... I would have never imagined ... clever HP-ish technique. Would love to see a sine wave and some frequency testing; but I can do that when I build one myself :-)

  • @10100rsn
    @10100rsn Місяць тому +4

    That is a neat circuit. Using a second optocoupler and the feedback of the op amp to correct the signal. Really neat.

  • @mcmurtr79
    @mcmurtr79 Місяць тому +3

    Add a small amount of dc offset to your square wave and you should remove the undershoot.

  • @sentientartificialintelligence
    @sentientartificialintelligence Місяць тому +1

    Wow you are amazing! Hopefuly this channel can develop my passion for electrical engineering

  • @tedknowlegy
    @tedknowlegy Місяць тому +1

    Sony had a TV monitor that used an optocoupler for video and another one for audio, back in the day.

  • @gamerpaddy
    @gamerpaddy Місяць тому +2

    sunfire used a optocoupler to isolated the analog audio signal from the input board to the preamp as the whole internal circuitry was live to get rid of the big heavy transformer and just run the power amp straight from 110v mains. but still had the rca inputs galvanically isolated.
    he didnt use a dual optocoupler but one that has its Base pin broken out to set some sort of pre-bias. well yea it only needed to go up to 150..200hz anyways.
    they put like 15mA onto the led and modulated the signal +-5mA onto it or something

  • @salehsalehi8955
    @salehsalehi8955 Місяць тому

    I like your IR reflow oven !!

  • @roflchopter11
    @roflchopter11 Місяць тому

    Some time ago, I took over a modular battery management system that used 4 optocouples to charge a capacitor from a Li Ion battery and then connect it to an isolated microcontroller to measure. It didn't work great, and I'm amazed it worked as well as it did.

  • @clytle374
    @clytle374 Місяць тому

    Cool project. I found that a couple years back when trying to answer a "how illI do this". iirc it was called servoing a optiocoupler. I also made the assumption that digitizing it and shipping it over fiber would be the correct answer, but I had lots of problems finding the parts ( TX, RX, fiber) I finally thought maybe it would be done with signal transformers for the data. But I dislike that idea for a few reasons. This is for a DC load project I'm halfway through the mental process designing. It's still suffering feature creep like building as modules that could be put in series or parallel keeps coming up, but needs to do 500W and 1000V. I already got 4 mosfets for the job IXFK52N100X. If you have any fiber optic link insights, I would love to hear them.

  • @JoeGoesXtreme
    @JoeGoesXtreme Місяць тому +1

    I forgot to mention, that the spikes you are unable to compensate in the case of the square wave may be due to the bandwidth limitation of the opamp. I think of this because the LED will turn on fast, and so will the phototransistor, but I have doubts about the slewrate of the OPAMP

  • @edmaster3147
    @edmaster3147 Місяць тому

    Really enjoy this linearity demonstration. Perhaps, I don't remember, you covered this, but as I am tinkering a bit with audio stuff, did you measure below 10% of the bandwith of the opamps? It seems to b e a general rule to pick an opamp that has a bandwith of at least ten times the desired bandwith, in order to keep distortion away. But it's quite a science, those opamps ;)

  • @udhayakumara4033
    @udhayakumara4033 Місяць тому +1

    Why triangular only? Can you show us DC accuracy?
    It will be useful for sensor and analog signal isolation.

  • @fsphil
    @fsphil Місяць тому

    Would something like this work with a composite video signal?

  • @johnfox2483
    @johnfox2483 Місяць тому

    RY2 potentiometer doesn't set LED Current ! Current must satisfy feedback loop.
    It regulates opamp output voltage, and indeed - may influence overshoot.
    And input voltage range.

  • @MyProjectBoxChannel
    @MyProjectBoxChannel Місяць тому

    It would be very cool to have a stereo version🧐. Will be great alternative to the audio transformers I'm currently using to get rid of ground loop hum on long cable runs

  • @jakebrodskype
    @jakebrodskype Місяць тому +2

    Would it be practical to reduce the feedback decoupling capacitor? That might be the cause of the undershoot.

    • @sponkii
      @sponkii Місяць тому

      On the contrary, it looks as it has too little phase margin, which will usually cause peaking.
      I hope IMSAIGuy reads this, because I believe that the peaking can be reduced by increasing the capacitor across the op amp feedback.
      The peaking is most likely cause by phase delay through the two optos due to there somewhat slow response, resulting in an overshoot from the opamp "being too fast" ( in reality having gain where there is little phase margin left)

  • @AnalogDude_
    @AnalogDude_ Місяць тому

    Would your try a audio "AGR", Automatic Gain Reduction with that optocoupler PC817 or H11 opto Fet?
    To see what it takes to achieve something like: Teletronix LA-A2 Opto Compressor accept the 290 Volts.

  • @stevenbliss989
    @stevenbliss989 Місяць тому

    The IL-300 / IL300 is better (than two PC817s), and is much higher bandwidth (at least 10x).

  • @Edmorbus
    @Edmorbus 21 день тому

    Thanks for sharing your work
    can you help me to make circuit schematics and code
    I want to read voltage with an isolated ground
    Mine setup is 4x 12v battery and 4x simple solar controllers Aliexpress
    Every battery have the own Solar controller
    I use the Esp32 and 1x ADS1115
    ADS1115 is a 16-bit, 860-SPS, 4-channel, delta-sigma ADC with PGA, oscillator, VREF, comparator and I2C.
    I use voltage divider 4x 6.44K 1% and 30K 1%
    The Solar controllers have switched ground if i connect the ground together i get errors
    The controllers are good it is charging the Batterys good.

  • @andymouse
    @andymouse Місяць тому

    I wonder what will happen if the second opto (U4) was also straddling the gap but the other way round (LED to the right) and the feed back was gathered from the output of U3A and fed across the gap to the first opamp U1A. Then you would have a composite setup where the feedback was global from the very last output back to the first input. In this first form anything the happens in the HV side does not get reported back or I should say 'Fed' back. Any noise created in the HV side does not get treated in the LV side. This is purely a thought and probably of no interest to anyone so please 'Commentators' don't get on my case :)......cheers.

    • @IMSAIGuy
      @IMSAIGuy  Місяць тому +2

      that would be great but you are using a non-linear device to feed back from a non-linear device.

    • @edmaster3147
      @edmaster3147 Місяць тому +1

      a composite setup comes to mind

    • @andymouse
      @andymouse Місяць тому

      @@IMSAIGuy Thanks, nearly bedtime for me but I will give it some thought, thanks again for replying :)

    • @mikebond6328
      @mikebond6328 Місяць тому +1

      I had this thought also but assumed there was a good reason it wasn’t done that way.

    • @andymouse
      @andymouse Місяць тому +2

      @@mikebond6328 Yes I'm struggling to understand but Very Kind IMSAI Guy gave me a thought to think about tommorow ! thanks for your comment :)

  • @scottgilson3247
    @scottgilson3247 Місяць тому

    Nice! How about trying PCBway assembly service? It's very cheap and will save you a lot of time.

  • @JacquesMartini
    @JacquesMartini Місяць тому

    OH NO! He did it again! The rubbish circuit with two optocouplers! WHY? This is pointless in 2024! Use the standard IL300 circuit and be good! And a reflow over for a handfull of SMT components? C'mon! Heat your circuit with hot air to maybe 60-70°C an see it drift!

    • @joseppuig925
      @joseppuig925 Місяць тому +2

      Haha, yes. But for an educational circuit, you can't beat its universality: almost everyone has at least a couple of PC817 optocouplers salvaged from SMPS's!.

    • @andymouse
      @andymouse Місяць тому +4

      This is an educational channel and not an engineering challenge game show. You realy do seem to have missed the point of this circuit and it's purpose :)

    • @JacquesMartini
      @JacquesMartini Місяць тому

      @@andymouse Nobody is useless. He can still be a bad example.

    • @tiagoferreira086
      @tiagoferreira086 Місяць тому

      thanks for the part number, i will get some to test.

  • @shakaibsafvi97
    @shakaibsafvi97 Місяць тому

    Congratulations.
    It works... !!!