BJT filters and capacitance multipliers

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  • Опубліковано 27 січ 2025

КОМЕНТАРІ • 45

  • @petrusbosman4264
    @petrusbosman4264 9 місяців тому +7

    Thank you again sir for clarifying this industry wide misconception, I have seen this in many electronic books, even from the University.

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      Indeed, Thanks for comment.

  • @icesnk
    @icesnk 9 місяців тому +4

    Hello Professor, thank you for sharing your knowledge, wish you the best from Romania!

  • @gonzalomeabe5256
    @gonzalomeabe5256 9 місяців тому +3

    Hello, professor. Thank you so much for your videos! Very well explained and very informative. Greetings from Argentina!

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      Thank you for your kind note.

  • @electroquests
    @electroquests 9 місяців тому +3

    Thank you for the explanation and analysis! It has been very helpful!

  • @Zetex2000
    @Zetex2000 9 місяців тому +5

    Great video!! Maybe do a video about negative resistance devices and uses?😊

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +2

      Great suggestion! Will try. Thanks.

  • @hardrocklobsterroll395
    @hardrocklobsterroll395 9 місяців тому +3

    Do you have a suggestion for alternative circuits that filter that noise? I feel that it is especially important for suppressing 60hz ripple without having massive capacitors to charge

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      I will try to touch on it in a forthcoming video. Thanks for your comment.

  • @cmuller1441
    @cmuller1441 9 місяців тому +1

    7:21 I wonder if we could add a diode in series with Rf to increase the voltage drop.

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      Thanks for your input. Indeed you can, but better to add resistance to Rf to get a lower frequency break point. On the other hand , if the current drops you may still not have a sufficient voltage drop with the Rf.

  • @cmuller1441
    @cmuller1441 9 місяців тому +1

    13:21 I guess a solution is to combine a normal RC filter with small R to cut high frequencies with the RC+BJT (with higher R) to deal with lower ones (so you don't need a huge C)

    • @sambenyaakov
      @sambenyaakov  9 місяців тому

      But in the 'nirmal' RC filer the current will pass via the R?

    • @cmuller1441
      @cmuller1441 9 місяців тому +1

      @@sambenyaakov unfortunately yes. That's why you have to use a small R and can't filter low frequencies unless you have a ridiculously big capacitor. But that's OK if that tasks is done by the BJT+RC.

  • @Hirouche
    @Hirouche 9 місяців тому +2

    Professor Hello ,Thanks a lot for this clarfication, God bless you .

  • @BenjiShock
    @BenjiShock 9 місяців тому +1

    Ive used this circuit to remove a very small ripple on a 200V DC Supply. I needed to have a very clean output voltage and the load was minimal because it was for a supply for a sensor. What would you recommend instead in this case? I have to say it was a really good solution because it was easy, small and power used was minimal because of low current.

  • @jacksmith-se8lo
    @jacksmith-se8lo 9 місяців тому +2

    Thank you for the great informations
    can you please makes a lecture about capacitor control circuit with dual mosfet for resonance maintaining circuits

  • @vaks2l
    @vaks2l 9 місяців тому +2

    Well, it is not related to filtering, but low output impedance is a fairly important aspect of any power supply and this circuit enables it due to the common-collector configuration of the BJT. Nevertheless, no doubt that there is a huge misconception about the statements given in the Cadence presentation. Suggestion to all electrical engineers - please use relevant references to learn electronics (Sedra-Smith, Gray-Meyer, etc). Thanks for a nice video lecture!

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      👍🙏

    • @foobarables
      @foobarables 6 місяців тому +1

      Companies like Cadence and Altium should stay away from this kind of presentations on subjects they don't fully understand. It would be better if they would both concentrate on delivering quality software. Cadence used to be good. But not so for the latest versions they released. Altium is an other story.

    • @sambenyaakov
      @sambenyaakov  6 місяців тому

      @@foobarables 👍

  • @Cydget
    @Cydget 9 місяців тому +1

    If i'm understanding this correctly, you only consider a miller capacitance to be a capacitor multiplier circuit( capacitor across input to output). The bjt filters merely let you design for lower currents, and thus you can make r smaller without making the capacitor larger. Essentially you can move your pole into higher frequencies without needed a larger capacitor. The misconception being this effect does not actually increase capacitance in any way.

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      Thanks for your comments. There are other cap multiplier circuits that entail current amplification rather than voltage amplification (like base to emitter in BJT).

  • @binong7366
    @binong7366 8 місяців тому +1

    wonderful clarification, thank you

  • @thephantompsychic
    @thephantompsychic 9 місяців тому +1

    Thanks Professor!

  • @k7iq
    @k7iq 9 місяців тому +2

    Awesome !

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +2

      👍🙏

    • @k7iq
      @k7iq 9 місяців тому

      @@sambenyaakov I hope you and your family is safe over there ! Thinking of you

    • @sambenyaakov
      @sambenyaakov  9 місяців тому +1

      @@k7iq thnks. Thanks for concern. We are personally OK but under a lot of tension. Hoping for a resolution soon

    • @k7iq
      @k7iq 9 місяців тому

      @@sambenyaakov Glad you are OK. It has to be hard. Things will be fine, I'm sure.

  • @vicentematricardi3596
    @vicentematricardi3596 9 місяців тому +1

    Gracias !!!!❤

  • @tamaseduard5145
    @tamaseduard5145 9 місяців тому +3

    👍🙏❤️

  • @ЁбрагимИпатенкоибнАдхарма

    Very interesting, thank You!
    and some bla-bla-bla in order to make this content rated as it should