Regulators help

Discussion in 'The Projects Forum' started by dominik0801, Jun 3, 2014.

  1. dominik0801

    Thread Starter New Member

    Jun 3, 2014
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    0
    Hi! I'm working on a project, a battery powered PC, but without that picoPSU thing, don't ask why i dont buy it, it has many reasons.

    I just want to know, wich regulators do I need for it.

    I want it like this:

    BAT1
    |
    CAPACITOR (make the voltages stable)
    |--------5vREG----CAPs-------
    |------------12vREG---CAPs---
    |------------3.3vREG---CAPs--


    So, the thing I want to know here, wich regulators i need to make this(wich model, or ?V and ?A), and also
    what regulator to make -12v and -5v(or how to make them)?

    Some info about the PC wich i want to be powered like this:
    miniATX board, no 4pin 12v
    AMD athlon 2200+ underclock to 1GHz, so no fan.
    integrated vga
    1x512mb ddr
    1x20gb 5400rpm hdd

    Please, answer if you really can help, not by telling "impossible" because it is not, or by telling buy picopsu, because then you cant read. thx.
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    The regulators you choose will be dictated by the input voltage and the amount of current you require each one to provide.
    Its up to YOU to tell us how much current each one needs and the voltage of your battery power source.

    example.. Reply with something like (and fill in the axyz)
    My battery voltage is "A"
    My 5 volt rail needs to supply "X" amps max
    My 12 volt rail needs to supply "Y" amps max
    My 3.3 volt rail needs to supply "Z" amps max

    Then do you need through hole or surface mount?
    Do you have plans for heatsinks?
    Do you have plans for fans?
     
  3. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    It would be much easier to provide a useful answer if you would provide pertinent information such as battery voltage, current requirement for each voltage you need, physical size restrictions (because you said no fan and regulators must have heat removed and no fan means larger heatsinks).

    What that boils down to is that I really cannot help since you did not provide enough info. I suggest you gather more data on the unit you want to battery power then you hopefully you will get real answers and not questions and/or guesses as to what might be appropriate.

    So why did I even answer? Because in technical subjects for information transfer to be effective it is extremely important to supply facts so help can be forthcoming. And I just have to ask - "Why don't you just buy it?" Since you did not provide enough info I took the liberty to ask the un-askable.
     
  4. dominik0801

    Thread Starter New Member

    Jun 3, 2014
    7
    0
    My battery voltage is "18"
    My 5 volt rail needs to supply "5" amps max
    My 12 volt rail needs to supply "5" amps max
    My 3.3 volt rail needs to supply "5" amps max

    Then do you need through hole or surface mount? - Don't understand
    Do you have plans for heatsinks? Heatsink for the regulators (a big one)
    Do you have plans for fans? Yes, but if i can, then only try to put 2x8cm fan in

    Sorry for that i'm not really detailed, but i need help, because i'm going to buy the things tomorrow, and i tried to tell it fast.
     
  5. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    "Sorry for that i'm not really detailed, but i need help, because i'm going to buy the things tomorrow, and i tried to tell it fast."

    Not really good to 'not be detailed', or to be in a hurry unless you have lots of money to waste and lots of time to do it over cuz you bought the wrong stuff.

    My advice is to be detailed and take the time to do it right.
     
  6. dominik0801

    Thread Starter New Member

    Jun 3, 2014
    7
    0
    Ahh sorry man, and for everyone, you are right.

    I would like to use heatsink for the regulators, and 1x8cm fan for cooling the heatskin.
    And 1 another 8cm for the CPU.
    The CPU will be underclocked and will use less voltage.
    The VGA will be integrated, with 32MB
    1x5400RPM hdd will be used.
    1x512MB DDR1 stick for the RAM.

    So, the battery voltage is 18V.
    I need the correct regulators for the 5v, the 12v, and the 3.3v rails.
    All rails MAX. 5 amps, i hope i'm right.

    Please don't be mad at me, i will try to be more detailed in the future.
     
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    buy the picoPSU devices. ;)
     
  8. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    So if "The CPU will be underclocked and will use less voltage." does that mean you can get by with a 4 volt regulator, A 11 volt regulator and a 2.9 volt regulator?

    Don't think anyone is mad but pertinent information is key.


    Pertinent - HD speed is extraneous, under clocking, DDR stick, VGA, not helpful facts.

    Not real comforting to just hope you are right on "All rails MAX. 5 amps" That is a very important parameter to properly specify the regulators.

    The size of the fan is not too helpful until you find how much the power the regulators dissipate then the fan CFM and heatsink design come into play so you don't end up letting the smoke out of the regulators and your dear mother board and 5400 RPM HD. The main thing you must do is to keep the smoke on the inside where it properly contributes to reliable operation. Though you have not specified how long you want it to run.
     
  9. dominik0801

    Thread Starter New Member

    Jun 3, 2014
    7
    0
    Hmm, it is 23:00 here, but i still went to collect everything on to my table.

    Remember, that I don't want to use PCI / AGP cards!

    So, the +12v rail:
    HDD: 0.60A
    FANs: 2 x 0.25A

    CPU: Now trying ti figure it out, its an Athlon 2200+ CPU, but i don't know which rail it uses, because the motherboard hasn't get the 4 pin additional 12v for the cpu. But the CPU uses 57-62Watts on stock 1.8GHz speed. (I want to use it at 1.5 or less)

    What other thing uses 12v?

    5v rail:
    HDD 0.55A
    USB mouse + keyboard if it is important.

    3.3v rail:
    Don't know what can use it !

    http://www.tomshardware.com/reviews/power-supply-specifications-atx-reference,3061-2.html
     
  10. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    Do you have an ammeter?

    Actual measurements of consumption would be easier and more inclusive. Could catch things you are not considering.
     
  11. dominik0801

    Thread Starter New Member

    Jun 3, 2014
    7
    0
    Just a question:

    If a do this:

    BAT1---12v3Areg1}__
    |-------12v3Areg2}--|--output--

    Then the output will be at 12V 6A, or will i just get 2 12V rail at 3A current?

    sorry for all these dumb questions.
     
  12. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    I do not understand what you mean by "BAT1---12v3Areg1}__
    |-------12v3Areg2}--|--output--"

    Can you please explain what you mean. A diagram or schematic or more precise description would be helpful.
     
  13. dominik0801

    Thread Starter New Member

    Jun 3, 2014
    7
    0
    O sorry, here is what i mean:

    The "BAT" means the Battery, which is now a 18V source!
    12v3Areg is a regulator, wich is a 12v 3A one.

    But let me show you in a picture:

    [​IMG]

    I want to know, the output will be 12V 3A, or will it add the A together? (12V 6A)
     
  14. pmk

    New Member

    Jun 4, 2014
    1
    0
    I just need exactly the same! Could someone help me/us?

    Will the output be 12V 6A, or 12V 3A?
     
  15. dominik0801

    Thread Starter New Member

    Jun 3, 2014
    7
    0
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