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Functional Casemods?

Posted by Cliff on from the useful-boxen dept.

attercoppe asks: "I'm looking for opinions and advice from Slashdot readers on a case mod idea. I'd like to install a second (small, low heat, no fan) power supply to run a single CD drive. The idea is to basically integrate a CD player into the case, allowing me to ditch my bookshelf stereo (yay convergence!). But I want to be able to use it without having the computer booted (to avoid waste heat and all the associated fan noise - PS, CPU, and two 4" fans). The question is, can I wire an existing drive, and maybe one of the supplemental fans, into both the existing and the new power supplies? Will one PS get feedback from the other through the drive? Do I need a switch to choose which PS to use? I know I won't be able to use the sound card... that's ok. No, I won't have a tuner for radio - that may come later. Tips, ideas, ridicule?"

3 of 54 comments (clear)

  1. As far as audio out... by revmoo · · Score: 2, Informative

    As far as audio out goes, you can splice the audio out cable that runs out the back of the soundcard to whatever you are using to amplify the setup, it outputs a standard line-level signal, so it's perfectly usable, and will save you from having an unsightly cable running out the front from the headphone jack.

    You can get small, fanless power supplies that will give you 12v, you might want to check around hobby supply places, if you get lucky you might find one for pc components with a molex connector, but chances are your most likely find will be a non-pc power supply, which you can use just fine, you'll just need to make sure the voltage and current levels are the what the cd-rom expects, and probably splice an old molex connector to it to connect to the cd-rom properly.

    Good luck in your utterly useless venture :)

    --
    I would expect such blatant racism on Fark, but on Slashdot? Mods please ban this asshole.
  2. No workie by pbox · · Score: 3, Informative

    Connecting outputs of two power supplies directly is a sure way of blowing up one or the other. Think about it this way: one is outputting 5.00V, the other one is 5.02V. You connect them together and the 0.02V difference will have to be resolved. The wires have negligable resistance (let's say 0.01 Ohm), so you will have (I=U/R) current that is 0.02 V / 0.01 Ohm = 2 A ! Doing nothing than disspicating from both PSUs. In real life 5V +/- 5% will give you 0.5 V max difference, and the wires are not much, so it will actually be likely to dissipate much more than my example.

    You can connect diodes from both PSUs, pointing towards the CD, but the diodes have a 0.7V drop...

    Or you can just buy that MSI barebones system, that already has the functionality that you crave...

    Use the Goggle, Luke!

    --
    Code poet, espresso fiend, starter upper.
  3. Why 2 PSU to CD? by Papineau · · Score: 1, Informative

    Why having 2 PSU to the CD? The second one (only for CD) will be able to always power it if the primary is only connected to th MB. Since the CD and MB talk to each other only through the IDE cable, and this cable is meant to convey signals (ie, no current), there shouldn't be any problem with the minimal different voltages both PSU will supply. Of course, that means having the second one always on if you want to use the CD at the same time than the computer.

    Of course, if it all burns in giant flames, don't point me...