NPN Transistor with no uncoupling capacitor

Discussion in 'Homework Help' started by ElectricMagician, Dec 2, 2013.

  1. ElectricMagician

    Thread Starter Member

    Jul 26, 2012
    57
    0
    Hello,

    Can we assume the voltage encircled in red to be 3V?
    What about the cuts in the line carrying Ib, do they mean anything? Or simply a printing issue?

    Thanks
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,809
    1,105
    Not exactly, allowing for IB1.
    Ignore the line cuts.
     
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  3. WBahn

    Moderator

    Mar 31, 2012
    17,777
    4,805
    Since you are only looking for the transistor terminal currents, neglecting the base current in determining the base voltage should be fine. The base current is going to be about 3% of the bias circuit current. So you can expect the base to be roughly 3% lower, or about 2.9V.

    If a 3% error in your answers won't cause them to be counted wrong, then you should be okay. But since you have the information you need, you might as well take the base current into account.

    I think the line cut is a printing issue.
     
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  4. LvW

    Active Member

    Jun 13, 2013
    674
    100
    Yes - I agree with WBahn.
    According to my (rough) calculation the base voltage is even closer to 3V as estimated by WBahn. It is about VB~2.96 volts.
     
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