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Thread: 12volts @ 3 amps........any ideas?

  1. #1
    Constant Bitrate
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    12volts @ 3 amps........any ideas?

    I need this circuit to power my 12 inch lcd. It doesnt matter if the low voltage is 11-12 volts, as long as it can handle the 13.9 volts I get while my car is running. ANY help would be appreciated.

    I figure that it wouldnt take much more than an 4 or 5 components, but this isnt my area.
    If someone could draw a small diagram that would be great.

    Eagerly awaiting someones help.

  2. #2
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    I personally think that the best way to do this would be to parallel 3 or 4 1amp low dropout voltage regulators... Why use 3 lower powered regulators when you can use a higher powered one??? I have tried this before (using one 5amp 12volt, low dropout regulator, and was unable to get a stable voltage even when the car was being revved.... Using regulators in parallel will mean a much more stable output with a lover voltage input.. 13volts should give you stable.. where as, with the 5amp IC, with over a 14volt input, the voltage was still low... (around 11volts i think) So, someone like to start an argument???

  3. #3
    FLAC Mastero's Avatar
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    genesis use the LM1084-12 (National ) IC they are 12volt 5amps low dropout works like a charm in my setup ..... you will find a application design on their site ..

    And james chill .......


    Mastero

  4. #4
    Constant Bitrate
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    Thanks Mastero, looks good.

  5. #5
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    Thats the IC I used.. :P the LM1084-12 and it wouldn't give me clean regulation without atleast a 14volt input.. try it if you want, might work, might not...

  6. #6
    Retired Admin Aaron Cake's Avatar
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    There is a 3A version of the LM7812 in a TO-3 style case. I have used it with success at about 2.5A. Note that you will need a nice sized heatsink. Sorry I don't know the exact part number.

    Paralleling 3 1A regulators is a bad idea, as has been explained 300 times on this board already. It may work, it may not.
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  7. #7
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    It should work, but you will have excess heat produced as the regulators will "fight" with each other..

  8. #8
    FLAC Mastero's Avatar
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    sometimes people just dont want the easy way out....!

    aaron forget it .. dont argue

    god is great
    mastero

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