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Thread: bILDA DAC doesn't work with ATX power supplies

  1. #1
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    Default bILDA DAC doesn't work with ATX power supplies

    The bILDA DAC board is designed to work with a power supply that will supply 12V, -12V, and 5V on the Molex connector, whereas a normal ATX power supply only supplies 12V and 5v!

    Do European power supplies all have a blue wire like in the bILDA prototype photos?

    http://www.linux-laser.org/images/bilda/bilda1.jpg

  2. #2
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    Nope, thats just a rewired molex conn.

    to get +12 and -12 V:

    take two +12 power supplies, tie together +12 from one supply with ground from the other like so:

    +12v (+12v and ground) ground

    and youll get:

    +12v, 0v, -12v when measured from either side to 0v with a voltmeter

    Do not consider 0v to be a "good" ground point... its a differential, but im just being nitpicky.

  3. #3
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    hehe,

    just get a open frane switchmode psu. I think its going to be alot neater than 2 coimputer psu's

  4. #4
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    Quote Originally Posted by Spec
    Nope, thats just a rewired molex conn.

    to get +12 and -12 V:

    take two +12 power supplies, tie together +12 from one supply with ground from the other like so:

    +12v (+12v and ground) ground

    and youll get:

    +12v, 0v, -12v when measured from either side to 0v with a voltmeter

    Do not consider 0v to be a "good" ground point... its a differential, but im just being nitpicky.
    Yes but be prudent ! some power supply have ground (0V) connected to earth and when you will connect them you will short 12V and 0V by the earth.

    If you want to use a PC power supply, use yellow (+12V) black (0V) and blue (-12V) (for atx psu verify before ). You can find the blue wire on the motherboard connector.
    and if you use a dedicated PC ATX psu you can short the green wire to a black wire (with a switch) to power it on.

    sorry for my bad english.

  5. #5
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    If you're building it in case, get an ATX extension cable to grab the power from
    it, if you doing it external box, buy a dedicated PSU +5/+12/-12, they run $10
    so are cheaper and far cuter than ATX power supplies (unless you already
    have one and don't mind a bix box)

  6. #6
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    Default Re: bILDA DAC doesn't work with ATX power supplies

    Quote Originally Posted by eric343
    Do European power supplies all have a blue wire like in the bILDA prototype photos?
    Yes, bILDA uses a modified Molex connector. I have chosen the molex plug as power supply connector because it is usually easy to get and cheap.
    And to make it work with an AT(X) power supply you only need to exchange the ground wire (black) next to the +12V wire (yellow) with the blue -12V wire from the motherboard connector.
    You would not be the first who connects bILDA to a standard floppy connector. This will not damage bILDA, but all outputs will stay at 0V. People then usally figure out what is wrong quickly when looking at the schematic.
    I've updated the documentation on linux-laser.org with a section on "power supply".

    bILDA2, which I've recently finished, is USB powered - no more power supply hassles.


    Greetings,
    afrob

  7. #7
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    Very small and clean! I like it! Is that block in the corner a DC/DC converter?

  8. #8
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    Quote Originally Posted by yaddatrance
    Very small and clean! I like it! Is that block in the corner a DC/DC converter?
    Thanks. Yes, the block is a DC/DC converter. It has some magic inside to generate +12V and -12V from the 5V USB supply.

    Greetings,
    afrob

  9. #9
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    You able to source enough current from the USB rail for that processor there and the dc/dc supply?

    Im no electronics expert, but that device is considerably more complicated than your average webcam

    Damn good work.

  10. #10
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    Yeah very great !!

    Are other modifications like resolutions ?

    I have seen : USB powered and colors channels ameliorations and of course the size of the board (because it's fully cms coponents ?)

    When we can get schematics ? and the price of the realisation is more expansive than the V1.0 ? (more harder but maybe not more expansive ?)

    thanks a lot

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