20mA Current Source

Discussion in 'General Electronics Chat' started by khanna_gunjan, Apr 27, 2006.

  1. khanna_gunjan

    Thread Starter New Member

    Jan 29, 2006
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    0
    I need to design a simple 20 mA current source, can any one tell me how do i do that
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    One fairly simple solution would be to design a current mirror.

    Below is a link to the tutorial on this website that explains this technique using an simple example.

    Current Mirror Tutorial

    After reviewing the information in this tutorial you can then consider the things you need to decide on in addition to the 20ma current source value.

    For example, what dc voltage do you have available to use in generating this current source

    From your post, it seems safe to assume that you are just looking for a constant 20 ma source. Is this a safe assumption?

    hgmjr
     
  3. khanna_gunjan

    Thread Starter New Member

    Jan 29, 2006
    8
    0
    Current Mirror Tutorial

    For example, what dc voltage do you have available to use in generating this current source

    From your post, it seems safe to assume that you are just looking for a constant 20 ma source. Is this a safe assumption?

    hgmjr
    [post=16614]Quoted post[/post]​
    [/quote]
    yes thats right, and the available voltage is 5 V dc.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Get the spec sheet for an LM317 adjustable voltage regulator. It will show you a way to set it up as a current source.
     
  5. khanna_gunjan

    Thread Starter New Member

    Jan 29, 2006
    8
    0
    Thanks !!
     
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