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Help to ID transistor...

Discussion in 'Electronic Components' started by GPE, May 3, 2007.

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  1. GPE

    GPE Guest

    Hi --

    I have recently purchased several hundred TO-3 transistors from a well known
    parts dealer. I prefer not to give their name right now pending resolution
    to this issue...

    I noticed these transistors were very nice looking, clean NOS Motorola's and
    thought nothing of them for awhile. In fact, I have already gone thru 200 of
    them....
    Tonight - I noticed variations in package (tooling, etc) as well as
    differences in insulation around transistor leads. Normally - I would think
    nothing of this either. BUT -- all these transistors have the exact same
    date code -- 0223. And - didn't Motorola change over to On Semiconductor
    in 1999?
    Counterfeits?!?! Aw [email protected]!!!!

    The parts seem to work well in a simple, low current power supply. Pretty
    much any similar NPN transistor would work. However, this is in a
    relatively high voltage supply -- 160 to 240VDC. Part may be good for gain
    and current but could still be rated for max of 60 volts of some awful low
    value. These parts work but I don't want a ticking time bomb by using
    voltages 4x what the parts are rated for....

    Is there a way I can find out what these transistors really are?
    If you pop the top - do any transistors have part marking internally on the
    die itself (i.e. etched in the corner)?

    -- Ed
     
  2. Mark Harriss

    Mark Harriss Guest


    You could cut one open and take a look for things like two die wired in
    parallel. Also take a look at : http://sound.westhost.com/counterfeit.htm
     
  3. Graham W

    Graham W Guest

  4. Eeyore

    Eeyore Guest

    Quite likely.

    If you pop the lid ( I saw it off) the differences will be remarkable. Things
    like the die being a fraction of the size for example.

    Just the difference in cans makes it clear to me they're knock-offs btw.
    Motorola's cans were always identical. And yes, the devices became ON ages back.

    They're not audio output devices are they ? A very popular counterfeit.
    MJ15003/4, MJ15023/4. Very popular indeed.
    http://sound.westhost.com/counterfeit.htm
    http://www.google.com/search?hl=en&...sult&cd=1&q=counterfeit+semiconductor&spell=1

    Graham
     
  5. GPE

    GPE Guest

    I'll do this, take some pix and post links to what I find this weekend (if I
    get time).


    These are actually simple NPN power transistors. Used for high voltage
    regulator.

    -- Ed
     
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