AC-to-DCPower Supply - LTSpice

Discussion in 'Homework Help' started by PsySc0rpi0n, Jun 6, 2014.

  1. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
    1,184
    3
    Hi...

    I'm trying to simulate an AC-to-DC power supply converter. This is just something out of classes subject.

    I have 2 versions. V1 has a Voltage regulator built by someone from this forum. V2 is built with a voltage regulator that I found around he web.

    V1 is almost perfect but still has some ripple. V2 has almost no ripple but produces a peak voltage at the very beginning of the simulation.

    The goal is to have a free ripple AC-to-DC voltage converter with no voltage peaks at the very beginning. I know that these 2 versions has different Vout values but I think we can adjust Vout value to whatever we want.

    V1 is like 12V or 13V at Vout and V2 has Vout around 5V.

    What can I do to improve the setups??


    ...V3.asc is an update to V1.
     
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    380
    hi Psy,
    Being blunt, those three circuits are totally wrong, missing components.

    Get the datasheet for the LM317 and study it.

    Your regulator models do not display correctly on my PC.
     
  3. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
    1,184
    3
    Well, I've followed some tutorial to build it... Why you say it's totally wrong?

    I have just used a voltage regulator because it was suggested. I don't know that component!
     
  4. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi,
    Look at this example, you should have the LM317 model in your LTS.

    Change the 15V battery to a AC source and FW bridge

    E
     
  5. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
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    Under what name can I find the LM317???

    What is an FW bridge???? I don't know anything about FW bridges!
     
  6. Jony130

    AAC Fanatic!

    Feb 17, 2009
    3,963
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    FW = Full wave rectifier
     
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Surprisingly the name is .... LM317 ;). It's in the Power Products folder.

    Edit:
    BTW, you can post .asc sim files rather than .zip (which many people distrust).
     
  8. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
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    I can post .asc files but there were 2 more files, a .sub and a .asy. So, to avoid to upload 6 files, I zipped them!
     
  9. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
    1,184
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    Was this what you meant???
     
    • V1.png
      V1.png
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  10. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi Psy,
    Thats much better.:)

    The next experiment you could do is to add a mains transformer to your circuit.
    Also measure the 'heating' of the LM317 when powering different values of Load and the effect of the Vinp has on the LM317 dissipation.

    E.

    EDIT:
    Added sim and image, it shows a range of transformer ratio's you may find helpful.
     
    Last edited: Jun 7, 2014
  11. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
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    Morning Sir Eric...

    Big thanks for that...

    But I would like to understand why the example I posted couldn't work in real life!!

    Thanks
    Psy
     
  12. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi,
    Look at this marked up image of your circuit.

    E
     
  13. PsySc0rpi0n

    Thread Starter Well-Known Member

    Mar 4, 2014
    1,184
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    I have not enough knowledge to understand your circuit to an AC-DC power supply converter and why couldn't the other one work.

    Maybe later I can understand.

    Now I need to study for my exams!

    Thanks for all the help!
     
  14. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    380
    Hi Psy
    Look at this clip from the LM317 d/s. it may help, it gives some explanation of the components.
    E
     
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