5V to 12V DC:DC Circuit

Discussion in 'The Projects Forum' started by dj_johnnyg, Jun 20, 2009.

  1. dj_johnnyg

    Thread Starter New Member

    Jun 20, 2009
    Hi All,

    Been scratching my head over this for a few weeks now, and finally had the courage to sign up & ask the experts.

    I am wanting to run a small PC in an arcade machine.

    The PC is going to be run from a picoPSU, which converts all the necessary voltages for the PC from a single 12V input. The input current is 5A.

    Now, the PSU I have in the arcade cabinet has the following outputs:
    3.3V@12A, 5V@10A, 12V@2A

    My initial thought was to use a 5V to 12V DC to DC converter, such as the
    AM2D-0512. The issue is that the output current is only 167mA.

    Can I just use a transistor (or Darlington Pair) to up the current, or am I going about this totally the wrong way.

    Many Thanks

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Is there some reason why the PC (understood as meaning Personal Computer) does not have a functional power supply? Most PC supplies output dual polarity voltages, such as +/- 5VDC, +/-12 VDC.

    Perhaps I have misunderstood what -
    - means.
  3. dj_johnnyg

    Thread Starter New Member

    Jun 20, 2009

    I have a Sega Arcade machine, which has a SUN PSU giving the outputs mentioned above.

    I have a case from an old Arcade Game motherboard (Sega Naomi) which I am putting a mini-itx motherboard into, to run some older arcade games.

    To make things easier for me, and to avoid having to have multiple PSUs in the cabinet, I want to use the PSU in the cabinet to run the PC.

    If the 12V supply had a high enough current, then I'd have no issues, but I need to get a 5A 12V output from any of the PSU outputs, so I can run the PicoPSU.

    So basically I need to get 12V 5A DC from any of the following:
    3.3V@12A, 5V@10A, 12V@2A



    You are correct, PC - Personal Computer
  4. steinar96

    Active Member

    Apr 18, 2009
    You say you need 12V, 5A. Thats 60W of power. Proplem is

    3.3V@12 is ~ 40W
    5V@10A ~ 50W
    12V@2A ~ 24W

    Technicly if you could settle for ~ 12V, 4A you could use a dc:dc converter on the 5V@10A output and thus end up with aprox 45W if its pretty efficient.
    Last edited: Jun 21, 2009
  5. SgtWookie


    Jul 17, 2007
    You'd need a 5v to 12v boost converter that's at least 96% efficient at 4A output. That's going to be difficult to find.