If you had a 12V DC 35A power supply laying around... what would you do with it?

Discussion in 'Home Theater Projects' started by RichardHOS, Mar 12, 2003.

  1. RichardHOS

    RichardHOS Second Unit

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    It's pretty nice, weighs a ton, but I can't think of a really good use for it. Seems like it should have some good use in a HT?

    If it were yours, what crazy thing(s) would you do with it?
     
  2. Seth_L

    Seth_L Screenwriter

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    You could try to power a car amp to use in your HT.

    However I would probably save it to power peltiers or watercooling equipment for my PC. [​IMG]

    Seth
     
  3. Dave Milne

    Dave Milne Supporting Actor

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    You could power some cool 12V halogen lighting without having to worry about expensive, humming transformers or non-dimmable solid-state converters...

    ...or how about a battery charger in case your car dies...

    ...or sell it to me for twenty bucks...I'm sure I can find a use for it.
     
  4. RichardHOS

    RichardHOS Second Unit

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    Twenty bucks huh? [​IMG]

    Hmm... halogen lighting. Yeah, I hadn't considered lighting applications. Now the wheels are turning again...

    One thought was a DC motor for a DIY electric screen. That could be complex though.
     
  5. Robert_Gaither

    Robert_Gaither Screenwriter

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    For a while I did have mine charging a car battery and running a car amp to push my first DIY home subs in my theater about 5 years ago, currently it's collecting dust but I'm thinking about buying one of those DC to AC inverters and try a cheap/generic Diy of the PSaudio power plant.
     
  6. Dave Milne

    Dave Milne Supporting Actor

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    Robert,
    Don't even think about it.

    First, inverters produce square waves so you'd be feeding your equipment very noisy power.

    Second, converting AC to DC and then back to AC has got to be the most expensive way I can think of... of doing absolutely nothing... except adding source impedance, noise, and a lot of heat. Unless your AC mains has frequent and egregious brownouts, you're not gaining anything.

    Put the money where it will do some good, like better speakers or room treatments.
     
  7. Dave Milne

    Dave Milne Supporting Actor

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    edit.... double post
     
  8. Mark gas

    Mark gas Second Unit

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    sell it!
     
  9. RichardHOS

    RichardHOS Second Unit

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    I would sell it, but being a mechanical engineer and constant tinkerer, I find that it comes in very handy from time to time. Like... when I start winding my own motor coils "just to see" what a particular winding does. Or whatever hair-brained crap I might come up with.

    But, mostly, it just sits in the closet collecting dust, only coming out every few months for a short burst of muscle flexing and eyebrow raising, and then back to its closet. It sits next to the pair of one farad capacitors...

    Seems like I could find something useful for it to do when it's "off duty." [​IMG]
     
  10. NikhilC

    NikhilC Auditioning

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    Depending on the transformer's construction, you could just rewind the secondary with more turns and a center tap - as the primary can already handle 420VA at least, it could be a nice 25-0-25 supply at 8 amps or so, with +/- 35v rails after rectification. More than enough to permit, say, four LM3886 amps to operate at full output into 8 ohm loads (~50-60 watts).

    It'd be a good chance to play around with active crossovers and biamplification - for example, the Alesis amp modules at Apex Jr. would be a great starting point. Active crossovers + two amps for $5, plus $4 for a second LM3886 to run both amps on the same power supply.

    Just one of many options...

    -Nikhil
     
  11. RichardHOS

    RichardHOS Second Unit

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    Another interesting thought. [​IMG] An active crossover might be very useful indeed.
     
  12. Hank Frankenberg

    Hank Frankenberg Cinematographer

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    Trade it for something useful.
     
  13. Francesco Chu

    Francesco Chu Auditioning

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    12V DC is very useful for motors...so why not motorized masking system. Couple with a bunch of microcontrollers and motors and you are laughing.
     
  14. Leo Kerr

    Leo Kerr Screenwriter

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    I second the lighting idea. Most 12v transformers that come on the halogen lighting from Home Depot are usually pretty bad.

    420 watts of 12v... that gives you 21 normal fixtures, or 42 small ones....

    Leo Kerr
     

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