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DC power supply from AC through bridge rectifier

Discussion in 'Electronics Homework Help' started by vick5821, May 22, 2012.

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  1. vick5821

    vick5821

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    Jan 22, 2012
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    I make it something like [REMOVED ANSWER]

    Or something like that. It's a fairly meaningless figure because any additional load or other fluctuations will change it
     
    Last edited: May 22, 2012
  3. gorgon

    gorgon

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    Jun 6, 2011
    Normally the mains voltage will fluctuate a bit over the day/load, I would guess as much as +/-10%. Distance from the nearest distribution transformer will also count.
    To get a stable 6V output from the power you'll need a regulator after the rectifier/capacitor bank. Most linear regulators need a bit of overhead voltage to perform, meaning that the base AC voltage from the transformer need to be a bit higher than the required output voltage.

    The circuit you post will give around 7V unloaded or with a small load. Loading it will reduce the output as Steve said.

    TOK ;)
     
  4. poor mystic

    poor mystic

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    Apr 8, 2011
    :)
    If you're not sure what that all means why not post a cct diagram, which should include the required currents and voltages, and specifications of the transformer you intend to use.
    We could tell you what it needs and how to connect it all up.
     
    Last edited: May 22, 2012
  5. vick5821

    vick5821

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    I used a 6V transformer. And I want to step it from 240V to 6V. Unloaded means how ? the 10k consider as load ? how can I achieve near to 6V for the load ?

    Thank you
     
  6. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    The best way is to use a regulator. Resistors won't do it.
     
  7. vick5821

    vick5821

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    we are not allowed to used regulator :( Just resistor and capacitor. Old time smoothing and filtering
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    And why didn't you post this in the homework help section?

    It's not like you're new around here...
     
  9. vick5821

    vick5821

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    Actually this can be the general electronic stuff too :)
     
  10. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    But if you post your homework in the wrong section you indicate to me that you want answers without doing any work yourself.

    It doesn't make me want to assist you.
     
  11. vick5821

    vick5821

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    Jan 22, 2012
    Ok sorry steve. Please move this thread
     
  12. poor mystic

    poor mystic

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    Apr 8, 2011
    :)
    Anyway, the point of the exercise is probably not for you to make a stable power supply but for you to exercise your mathematical wits to correctly design a filter to specifications laid down in class. That's what I'd teach, if anything.
     
  13. vick5821

    vick5821

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    mathematical wits means ?
     
  14. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Your ability to do arithmetic.
     
  15. poor mystic

    poor mystic

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    Apr 8, 2011
    :)
    I presumed that a mathematical description of filter design had already been part of your course, and I apologise for any offense - .it's just that once you have such an understanding things get easier.
    I may have over-estimated your intelligent laziness.
     
  16. vick5821

    vick5821

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    Jan 22, 2012
    I am trying now..I put 5 series diode after the rectification output and I get around 6.2 + V. Is this practical or appropiate ?
     
  17. poor mystic

    poor mystic

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    Apr 8, 2011
    Ah,
    but post a circuit diagram, please!
    :)
     
  18. vick5821

    vick5821

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    Jan 22, 2012
    Posted in the first post :)
     
  19. davenn

    davenn Moderator

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    That link doesnt work!!

    post the pic in this forum :)

    Dave
     
  20. vick5821

    vick5821

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    Jan 22, 2012
    [​IMG]
     
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