CarPSU - 12V wide Input and 6V Buck (StepDown)

Discussion in 'The Projects Forum' started by tudstudent, Jun 6, 2009.

  1. tudstudent

    Thread Starter Member

    Jun 6, 2009
    20
    1
    Hi all,

    My first post, so I hope you can help.

    I am trying to make my own PSU for various tasks in my car (TFT, Servos and some other stuff). This PSU has to be able to deliver 6V/10A and 12V/10A.

    For this I have found 2 schematics:

    12V Wide input with buffer:
    http://dren.dk/carpower.html

    It is version 3 at the bottom of the page. Only problem is that they use some sort of inductors and 1 transformer (if I am right). I am not very well known with those 2 components so I need your help in here:

    L1 and L2 minimal 12mH, so I was planning to buy:
    http://nl.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMsg%252by3WlYCkU6t7%2fE41dbzj2tFL3C%2fMkl8%3d

    For the other coil I have no Idea, there is stated:
    - RM10
    - Gap 0,003"
    - 13:13

    6V Buck (StepDown):
    http://cds.linear.com/docs/Datasheet/3800fb.pdf
    Page 20 is the schematic 6,5V-55V converted to 5V 10A

    By changing R1 and R2 I can change the output to 6V if I am correct.

    The components in this electric circuit I am not sure about are:
    DS3 = B160

    C5 = Sanyo Poscap 6TP220M
    Could I use: http://nl.farnell.com/sanyo/6tpb220ml/capacitor-220uf-6-3v/dp/9188584

    May be someone can help me on these questions? If you need additional Information just let me know. I am hanging on this data before I can design my PCB and control circuits!
     
    Last edited: Jun 6, 2009
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,346
    Hello,

    The link to mouser does not work.
    Perhaps a partnumber will help.

    For R1 AND R2 : you are correct, teh reference voltage is about 1.23 Volts.
    You correct the values (voltagedivider) to have 6 Volts as output voltage.

    [​IMG]

    As for C5 AND C6: I would take capacitors with at least 10 Volts.

    Greetings,
    Bertus

    PS Groeten uit Amsterdam.
     
  3. tudstudent

    Thread Starter Member

    Jun 6, 2009
    20
    1
    Changed the link in first post to:
    http://nl.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMsg%252by3WlYCkU6t7%2fE41dbzj2tFL3C%2fMkl8%3d

    The ones I selected are from the TPB branch, the one the LM3800 has stated is a TP branch one, which is not on the site anymore.

    Have you also looked at the tranformer coil 13:13 don't have a clue what to do with it!

    Ps. Hi from Den Bosch
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,346
    Hello,

    For the 13:13 I think they mean to use a ferrit clamp.
    See the PDF for the page from mouser.
    Take two wires twist them together.
    Wind them 13 times round the clamp.
    close the clamp with some space between the ferrit parts.

    Greetings,
    Bertus
     
    roztech likes this.
  5. tudstudent

    Thread Starter Member

    Jun 6, 2009
    20
    1
    I understand, but I was looking for a nice and shiny PCB solution.
    What about my other questions in regarding to the other components I use?
     
  6. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,346
    Hello,

    The inductors will be fine.
    The capacitors , like I said , take the 10 Volts version.
    For the double inductor (transformer) perhaps there is someting in the attached PDF.
    The PDF comes from mouser (so the chokes will be sold there).

    Greetings,
    Bertus
     
  7. tudstudent

    Thread Starter Member

    Jun 6, 2009
    20
    1
    For the 12V power suply I have switched to an other schematic:

    http://cds.linear.com/docs/Datasheet/3780fe.pdf

    Page 28. It is 5A, which is enough for my TFT.
    I Switched because all components needed to be on the same PCB and did not want to be forced to build my own transformer.
     
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