Connect with us

half wave rectifier + voltage increase

Discussion in 'Electronics Homework Help' started by Mobin, May 4, 2017.

Scroll to continue with content
  1. Mobin

    Mobin

    13
    0
    May 1, 2017
    hi!
    I've been assigned to design the simplest circuit to get the Output voltage(green) from the input(red) and simulate it by OrCAD:

    photo_2017-05-05_01-05-31.jpg

    I have done this: Capture.JPG

    And the output was:
    Capture.JPG
    NOW the problem is that the output starts at about 0.06s and end at 0.44s while it must be between 0.00s and 0.50s
    How can I adjust that?
    Is it a problem of diode model?
    we've just been taught about BJT Transistors and I'm not sure if using them is necessary or not?
     
    Last edited: May 4, 2017
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    11,794
    2,749
    Nov 17, 2011
    When the input voltage is 0 or negative, the diode is not conducting and the output voltage is determined by V3. Therefore V3 = 3 V is correct.

    Your idea of using V2 to offset the input voltage is also correct. The voltage you have chosen is not correct.
    Consider the time t=0 where the AC input voltage is 0 V. What is the voltage you need to apply to V2 to make the diode pass 2 V to R1? It is not 1.6 V.

    Next consider the point where the AC input has its top amplitude (V(V1) = 2 V). What is the output voltage in that case? Hint: it is too high.
    What could you do to reduce the output voltage without afflicting the voltage for V(V1) <= 0V? Hint: Insert another component in the output circuit. Which one and where Is up to you.

    I hope that helps. We'd be glad so see your solution.

    Harald

    btw.: as this is an assignment, I'll move the thread to the appropriate section of our forum.
     
    Mobin likes this.
  3. Mobin

    Mobin

    13
    0
    May 1, 2017
    thank you
    I think i can use a transformer but I'm not sure if it's correct and also how to put one in orcad
     
  4. Harald Kapp

    Harald Kapp Moderator Moderator

    11,794
    2,749
    Nov 17, 2011
    You don't need a transformer, plus a transformer would not let pass the dc offset.
    Look at the output volateg with only R1 (and not the unknown additional component) in place. What is the value? What can you do to reduce teh value without a transformer. Hint: You already have R1 in place.
     
    Mobin likes this.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-