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Thread: How do I change a computer power supplt to give me + - 35v @ about 4amps per rail????

  1. #11
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    Also,I think you will need a circuit to prevent click-on-start and shutdown,if you don't want to blow your speakers.
    I've got a circuit that does that, the speaker output isn't switched on untill the amp has been powered for about 5seconds..

    So, no-one knows a site or has a diagram lying around for a switchmode power supply?? okay..

  2. #12
    FLAC
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    like Jeff said, for alot of things around us there are not easy answers......


    ....most ppl know this at one point or another, I like to call this "life"....

    (not a grinning smart-arse smile... just a refelction to what I wrote)
    Project - GAME OVER :(

  3. #13
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    Not my web page, but something to look at

    Go there, look on the bottom of the page. It is linear, unregulated, basic. Adding a regulator to it will increase your overall power supply rejection ratio (PSRR), hence lower 60hz noise. It is not small, but it is simple.

    If you're really bent on using a switching supply, good luck!

    Transformer basics

    Go there, and learn how to wind your own transformer. I recommend a toroidal as they have the least EMI (good for audio).

    If this is for home use, the size difference from a linear regulator vs switching is not really a big deal. It will be quite a bit heavier though.

    Presslab

  4. #14
    Retired Admin Aaron Cake's Avatar
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    Cool

    No matter what power supply you build, you will need a transformer. It's that simple. Switching power supplies are much harder to build than linear units, so not many people even bother to design them for hobbiest situations. Best bet would be to buy one on the surplus market.
    Player: Pentium 166MMX, Amptron 598LMR MB w/onboard Sound, Video, LAN, 10.2 Gig Fujitsu Laptop HD, Arise 865 DC-DC Converter, Lexan Case, Custom Software w/Voice Interface, MS Access Based Playlists
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  5. #15
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    Well, okay...
    could someone tell me then, how to modify a computer power supply so that the 12volts is 3 times the voltage??? It can be done right???

  6. #16
    Retired Admin Aaron Cake's Avatar
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    Cool

    No, it can't easily be done. If you're going that far, you might as well do it right and design a new supply that is actually meant to provide the higher voltage.
    Player: Pentium 166MMX, Amptron 598LMR MB w/onboard Sound, Video, LAN, 10.2 Gig Fujitsu Laptop HD, Arise 865 DC-DC Converter, Lexan Case, Custom Software w/Voice Interface, MS Access Based Playlists
    Car: 1986 Mazda RX-7 Turbo (highly modded), 1978 RX-7 Beater (Dead, parting out), 2001 Honda Insight
    "If one more body-kitted, cut-spring-lowered, farty-exhausted Civic revs on me at an intersection, I swear I'm going to get out of my car and cram their ridiculous double-decker aluminium wing firmly up their rump."

  7. #17
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    Fine, I'll keep looking around on the net and in books and see what I can find, thanx for the help..

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