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Thread: HomeMade powerSupply with Noise ...

  1. #1
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    Question HomeMade powerSupply with Noise ...


  2. #2
    Variable Bitrate
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    Hi, could you post your schematic? for two reasons..

    first: this way people have some more insight to what you're talking about

    second: I'm really interrested in how you made this, so I can copy it of you

    cheers!
    If at first you don't succeed.........
    destroy all evidence you tried

    for info on t6369c LCD or Presslab's powersupply check:
    http://www.namms.tk <=updated!!

  3. #3
    Dustin Haug
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    What kind of noise is it? Can you describe what it sounds like (i.e. a whine or hum). How do you have it connected to the car's electrical system?

  4. #4
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    Hello

    For marsjell : here is the url where I upload the schematic : http://www.nioux.fr.fm/mp3car/alim/alim.htm ( alim in french says PowerSupply )
    If you make the same with changes, email me please. i would like to improve it ...

    For Dustin Haug:
    Sorry I'm french and don't understand whine or hum.
    There are two noise. A helicopter noise in the background. and another noise only when the engine is on.


    Thanks ...

  5. #5
    Maximum Bitrate Raas's Avatar
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    Hi,
    As you said on your website (where the 12v rail is.) The psu probably needs 14v to operate.. True, It needs 14.2v to be exact...

    Quote from the datasheet:
    The input voltage must remain typically 2.2v above the output voltage even during the low point on the input ripple voltage
    There are two noise. A helicopter noise in the background. and another noise only when the engine is on.
    I think this 'helicopter' sound is the hard-disk spinning, I heard it once, but I don't know what you can do about it.. maybe get a better soundcard, as this one does not 'isolate' the sound too well, noises from the computer are picked up by the soundcard.

    I don't know about this hum. Normally you would have a hum like this when you are using an inverter. (grounding all electronic part to the SAME ground usually solves this).
    But I think you are using your own dc-dc-psu (if not, let us know). Still.... Ground everything to the same spot and make sure it is a decent ground.
    If this doesn't eliminate the noise you could always use a Ground-Loop-Isolator to remove the noise from the audio-signal-cable, but this is not preferable as this is just a solution to the noise, but it doesn't solve the origin of the noise.

    Hope this helps you out !

    Greetz
    Raas - The Netherlands
    ME: VIA epia m10000, lilliput 7', opus 150w, 80gb<br>
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  6. #6
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    Originally posted by Nioux:
    <STRONG>Hello, i have built a AT-PS but i have some problems with.

    I use MAX787 for 5V, MC78T12 for 12V and LM2575T-12 for -12V (see datasheet if you want schematic ...) and a L7905.

    My main problem is the noise. There is a noise. What should I do for this.

    Thanks ...

    PS. If anyone knows how to increase sound under linux, i would be interested ...

    Nioux [email protected] </STRONG>
    YOur distro should of came with a program called "aumix" run it and turn up the volume on PCM and mixer/master.
    24 y/o w/ Silver/Red
    2000 Honda S2000

    http://www.squeezer.net

  7. #7
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    Hi and thanks everyone.

    I have two power supply ( not all in the same time ). I have my own PS and the Sproggy One.

    My hard disk is very old (it's for tests) but with a AC-DC PS (250V in Europe), there is no noise. Maybe with the DC-DC PS, it could produce problems.

    What is a Ground-Loop-Isolator ? Is it possible to built one ?

    If I ground the GroundWireSound, could it remove noise.

    My card is an 5 years old Sound Blaster Pro 2
    If anyone has no problems withthis card, tell me.

    Thanks ...

    Nioux

  8. #8
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    I forgot to say that with the Sproggy PS, there is a Spoutnik Noise, bip, bip, bip, bip. And this noise doesn't depend on the Autoradio Volume ...

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