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Homework Help: Zener diode and transistor

  1. Apr 16, 2010 #1
    well first i saw this solution of a zener diode problem on net
    A 5.0v stabilised power supply is required from a 12v d.c. input source. The maximum power rating of the Zener diode is 2W. Load resistance = 1 kiloohm Using the circuit above calculate:

    circuit : http://www.electronics-tutorials.ws/diode/diode24.gif

    b) The value of the series resistor, RS


    12-5/(400mA) = 17.5 ohm

    so is the above solution right
    cuz i think it should be

    12-5/(405mA)


    second can somebody explain me a bit about ce transistor circuits
    first a little bit about what it does
    and secondly how does the circuit works
    like why theres grounding
    and also i saw that the emitter is connected to the positive terminal of one battery and the negative terminal of other
    so in that branch how will the current flow
    from postitve terminal of one batter to the negative of the other without passing through emitter? or in some other way
     
  2. jcsd
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