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Homework Help: NPN Transistor

  1. Apr 29, 2008 #1
    Hey guys, was just wondering if you could clear up some conflicting information i have found. In the v simply NPN transistor circuit, what is responsible for settings the quiscent point? Is it the voltage divider or Rc.

    I no that the voltage divider ensures that the amplifier is 'switched on' while Rc ensures .5Vcc is added to output signal. Therefor, wouldnt Rc be ultimatly responsible for settings the quiescent point?
  2. jcsd
  3. Apr 29, 2008 #2
    If you have an emitter follower, the quiescent output voltage is always a diode drop below the output of the voltage divider.

    With a common emitter amplifier the collector current is set by the voltage divider (and there will be an emitter resistance as well for succesful biasing), but the voltage drop across Rc will be I_c * R_c. So the answer should be: all of them
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