Want to build a 12v bench supply for car audio equipment

Discussion in 'The Projects Forum' started by earthtodan, Sep 6, 2010.

  1. earthtodan

    Thread Starter Member

    Dec 3, 2008
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    I'm slowly integrating spare car audio equipment into the stereo in my garage, using a car battery and charger as my source. I'd like to build a proper power supply with sufficient current available to power a basic system with a speaker and sub amp (say 25A to 50A). I would also use it to test equipment, etc - anything requiring 12 volts. There are a lot of schematics available online, but I don't know enough about power supplies to know which is right for me. Does anyone know of a good buildable supply appropriate for this application?

    Dan
     
  2. marshallf3

    Well-Known Member

    Jul 26, 2010
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    I couldn't recommend any one over the other. Is this just for garage music or do you plan on servicing items in the future?
     
  3. earthtodan

    Thread Starter Member

    Dec 3, 2008
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    Main application will be powering two car audio amps for up to 2-3 hours at a time, not super loud. Anything else I happen to do with it will probably have a much lower current draw.
     
  4. sceadwian

    New Member

    Jun 1, 2009
    499
    37
    Buy new amps that work on mains... The speakers can probably be reused.

    You could use an ATX supply however you'll need some SERIOUS filter caps and inductors to keep the supplies noise low at full power. The lastest ATX specs provide... large currents on the 12 volt rails.

    If you can keep the ATX supply from tripping into a short circuit condition during turn on (charging the power filter caps) you'll get more power out of it over a car system by quiet a bit.
     
  5. marshallf3

    Well-Known Member

    Jul 26, 2010
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    This will of course depend on the power amps, some of those things are rather ineffficient and can draw peak currents so high that you'd end up needing a monster power supply.

    I think you'd be far better keeping an old car battery hidden under the bench with a trickle charger.
     
  6. earthtodan

    Thread Starter Member

    Dec 3, 2008
    24
    0
    This is exactly what I have now, powering the sub amp on 12V, while the garage speakers are on 120VAC. I could probably add a speaker amp on the 12V battery supply but it just seems kind of janky. Plus, I don't think the battery would last through an all-afternoon garage session.
     
  7. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    605
    24
    You could build a pwoer supply designed for amateur radio. Some of those can deliver 30A easily. They will be 13.8V as well. I have one (VK power mate) and it is awesome.
     
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