Current too much low ...

Discussion in 'Power Electronics' started by Rawand, Feb 17, 2017.

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  1. Rawand

    Thread Starter New Member

    Feb 17, 2017
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    Hello ... I wanna help, my modem d-link work with 12v, 1A .... i have telephone line contain 48v i want uses the power for my modem , i use voltage regulator l7812cv , it convert 48v to 12v , but modem doesn't work i think the source current is too low therefor modem does not work , so how can boost current or any solution
     
  2. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    You can not use the telephone line to power a modem.
    When you draw to much current, the telephone line might get disconnected.

    Bertus
     
  3. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    3,502
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    At 12v, you may only get 60mA. Likely not enough to run a modem.

    Also, in the US and Canada, this is illegal. You don't mention where you are from.
     
  4. Kjeldgaard

    Member

    Apr 7, 2016
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    Other sources states Off-Hook as about 3 to 9 volts, and 15 to 20 milliamps of DC.
     
  5. Rawand

    Thread Starter New Member

    Feb 17, 2017
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    Hello ... Thanks 4 fast reply .. Am from kurdistan " north iraq " we have problem in electricity , i saw tutorial in youtube it use phone line to rechatge cell phone converting voltage to 5v
     
  6. MrChips

    Moderator

    Oct 2, 2009
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    It doesn't matter what you saw on youtube, it is still illegal.
     
  7. Rawand

    Thread Starter New Member

    Feb 17, 2017
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    Thanks 4 Reply ... I saw tutorial in youtube it use telephone line for recharge cell phone same idia , he use voltage regulator to convert to 5v
     
  8. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    In many countries it is forbidden to use the power from the telephone line.
    Check the rules in your country.

    Bertus
     
  9. Rawand

    Thread Starter New Member

    Feb 17, 2017
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  10. Rawand

    Thread Starter New Member

    Feb 17, 2017
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    Ok i understand but i want know if possible to increase or amplify current without change in voltage.
     
  11. MrChips

    Moderator

    Oct 2, 2009
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    The answer is no.
    Your modem needs 12W of power. You are not going to get 12W from the phone line.
     
  12. Rawand

    Thread Starter New Member

    Feb 17, 2017
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  13. Rawand

    Thread Starter New Member

    Feb 17, 2017
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    O
    Ok thanks, by the way i'm Architect but electronic is my hobby
     
  14. bertus

    Administrator

    Apr 5, 2008
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    Time to close the thread.
    We will not support illegal activities.

    Bertus
     
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