Help with identifying a transistor

Discussion in 'General Electronics Chat' started by nerdegutta, Mar 22, 2014.

  1. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    Hi.

    Could someone verify that this is a 2N3904 transistor. I do not remember, nor did I label the envelope it's in.

    [​IMG]

    ... and the guys at Google are not helping ... :)
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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  3. t06afre

    AAC Fanatic!

    May 11, 2009
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    Maybe Google did not help you, but by using the Altavista search engine I came up with this:p http://www.s-manuals.com/smd/r1 So I think you are on the correct track. SMD markings are an odd field. But serching on the 3 first letters only and function like "R1A transistor", or "R1A NPN" often bring good results
     
  4. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    I assume it's an 2n3904. Yes, I know:"Assumtions is the mother of all f'ups"

    I'm living on the edge now, taking big risks... :eek:

    Thanks for the replies!
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
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    If you do not live on edge you are taking up to much space:D
     
  6. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    I'm not taking up nearly as much as you, Mister!!:D
     
  7. ian field

    Distinguished Member

    Oct 27, 2012
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    There are various SMD lookups online, some are PDF, you can convert the html ones into PDF with the CutePDF application.

    You have to watch out as some SMD markings are duplicated for 2 or more devices - usually identifying the package style narrows it down.
     
  8. Brevor

    Active Member

    Apr 9, 2011
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    I believe 1A is the marking for a 2N3904, The R may be the manufacturer possibly Rohm I know they make a 2N3904.
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    An "R" suffix can sometimes denote an alternative pin layout - it wasn't uncommon on stud rectifiers.
     
  10. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    The attached datasheet says that

    So I am pretty sure it's an 3904 npn transistor.

    Thanks for the replies!
     
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