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Transistor Intercom Circuit

  1. Sep 17, 2014 #1
    Attached with this post is a picture of an intercom circuit using only transistors. It is a two-staged coupled amplifier circuit. I have constructed this circuit for my college physics project. But for the report I want to know the functionality of every component of the circuit. I would be really grateful if someone could help me with this. Thank You!

    Attached Files:

  2. jcsd
  3. Sep 17, 2014 #2
    C'mon Taher - you can do better then that.... what do you know already.
  4. Sep 17, 2014 #3
    I've already constructed the PCB of the circuit. And now all I've got to do is to write a report where I must mention the functioning of every component. I'm not so good in electronics. :(
  5. Sep 17, 2014 #4

    jim hardy

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    From the pinned thread just above, titled "Do Not Post Homework or Coursework Questions Here in the EE Forum"

    Is it acceptable in some circles to get classroom credit for intellectual work one hasn't done? That's a surefire way to build incompetence and serves nobody's interest.

    Start at the beginning:

    What is the function of R1?
    How does the microphone work? (hint - it's probably an electret )
  6. Sep 17, 2014 #5
    The 0.1μf capacitor is used to couple the input signal with the base of the Q1 transistor. I don't know why R1 is used.
  7. Sep 17, 2014 #6
    And the mic converts the sound signals into electrical signals to feed to the amplifier circuit.
  8. Sep 17, 2014 #7
    I don't understand why the particular values of the components are used
  9. Sep 17, 2014 #8


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    The thought that comes to my mind is why was this project picked? You said yourself:
    Surely there was something else you could have picked.
  10. Sep 17, 2014 #9

    jim hardy

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