Ways to fry a transistor

Discussion in 'The Projects Forum' started by yamanq, Feb 24, 2016.

  1. yamanq

    Thread Starter New Member

    Feb 24, 2016
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    I am new to circuitry, and while working with transistors, I believe that I have fried them (they are always open). I found online that placing them the wrong way fries them, but does application of a lot of voltage also fry them? Is there a way to fix them?
    I am working with 2N2222A transistors and the voltage that I applied was 9V.
    Thank you in advance

    Edit: Schematic: [​IMG]
     
    Last edited: Feb 24, 2016
  2. ISB123

    Well-Known Member

    May 21, 2014
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    We need schematics. A damaged transistor can not be fixed.
     
  3. yamanq

    Thread Starter New Member

    Feb 24, 2016
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    I apologize, I have added a schematic
     
  4. #12

    Expert

    Nov 30, 2010
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    No resistors means no limit to the current. You have exceeded the current rating of your transistors. They can not be repaired.
     
    yamanq likes this.
  5. yamanq

    Thread Starter New Member

    Feb 24, 2016
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    Thanks for the help
     
  6. WBahn

    Moderator

    Mar 31, 2012
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    Your schematic doesn't make much sense. You are showing a currents in the transistor going the opposite direction they should -- and this is reflected in the very low current gain of one (how realistic that is I'm not sure).

    You also have an emitter-base voltage of 3.6 V. This part was an absolute max for that voltage of just 6 V, so that can get you in trouble, too.
     
    yamanq likes this.
  7. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Nice color beans! Or it is dots? Do they move ? If so, in what direction?

    What if the OP posts a schematics drawn in a non-fancy way?
     
  8. crutschow

    Expert

    Mar 14, 2008
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    (Some) Ways to fry a (BJ) transistor:
    Exceed the base-emitter maximum current rating.
    Exceed the base-emitter maximum reverse-voltage rating.
    Exceed the collector-emitter or collector-base maximum voltage rating.
    Exceed the collector-emitter maximum current rating.
    Exceed the transistor maximum junction temperature (power) rating.

    All of the above values can be found in the transistor data sheet under "Absolute Maximum Ratings".

    Sounds like you may have exceeded at least one of those in your experimenting.

    Note that the normal direction of base-emitter and collector-emitter current flow in a BJT is in the direction of the base-emitter arrow (opposite of what you show).

    Perhaps you should read up some more on how transistors work. :rolleyes:
     
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  9. WBahn

    Moderator

    Mar 31, 2012
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    And don't feel too bad about frying transistors -- it's one of the more effective ways to learn about this stuff and you are asking the right questions.
     
    Roderick Young likes this.
  10. Bordodynov

    Active Member

    May 20, 2015
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    This scheme uses a reversible mode transistor. When using the default transistor, this transistor has Beta_forvard = 100 and Beta_revers=1. Then, the emitter current (revesny mode) is the base current (emitter current=base current x Beta_revers) and collector current is the sum of the base and emitter currents. All this occurs in the presented image.
    I do not understand why is used reverse mode, but each in its perverted. There are relaxation oscillators that use this mode.
     
    yamanq likes this.
  11. Willen

    Member

    Nov 13, 2015
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    Hi ferrari,
    The program is called EveryCircuit and it's android app for android OS phones. The application simulates circuits and these beans moves and wave form swings (visualization of operation of circuit). For the beginner, it seems very nice simulator. But it's not totally free, just single stage of limited drawing area is free.
     
    Last edited: Feb 25, 2016
  12. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    If you are not able to track down any current limiting resistors, Yoou might want to look into a silicon carbide transistor. Able to glow red hot - above 650C - and function normally.

    Good luck.

    http://m.powerelectronics.com/power...rying-pan-fire-no-problem-silicon-carbide-ics
     
  13. yamanq

    Thread Starter New Member

    Feb 24, 2016
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    Thanks everyone for your replies you were very helpful!
     
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