LM317 +short circuit protection

Discussion in 'The Projects Forum' started by binod, Apr 6, 2009.

  1. binod

    Thread Starter New Member

    Apr 3, 2009
    4
    0
    Hi this is my first post ,
    i am working with voltage regulator .One that i am using is LM317.
    the problem is that when ever the output is getting shorted,it is drawing a lot of current .
    i want to shutdown LM317 as the output is shorted.
    can anyone advice?
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Go to National Semiconductor's website:
    http://www.national.com
    Download the datasheet for the LM117/LM317 regulator.
    Look on page 19. The 2nd schematic is for a current limited voltage regulator.
     
  3. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Post your circuit.

    How much current does it draws when shorted?
     
  4. binod

    Thread Starter New Member

    Apr 3, 2009
    4
    0
    But why short it? you doing that on purpose ?[/quote]

    I am designing a power supply with three outputs with flyback topology.The Design is such that it can support limited current. One of the output of flyback is connected to LM317 to give constact voltage .

    The output of the Lm317 is connected to a connector having numerous pins.
    There is a chance of getting short circuit at this connector .When ever this short circuit occur it draws huge current overlimiting my flyback current limitation .hence i want that whenever the LM317's output is getting shorted it gets shutdown .

    Help me how it can be done?
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Did you bother to look at the datasheet I suggested?

    A solution is on page 19.
     
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