h and y parameters for CB and CE transistors

Discussion in 'Homework Help' started by evol_w10lv, Nov 21, 2013.

  1. evol_w10lv

    Thread Starter New Member

    Feb 19, 2013
    When I measure CB ciruit:
    I have got these results:

    And here CE:

    So.. here is table, how to calculate h parameters:

    But I don't understand, am I using it correctly. When I use results of my table where results are 0, then always h parameters is 0 or infinity.
    Both circuit is without resistance.. so Hie should be 0?
    How to calculate there parameters correctly?
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
    You h parameters table don't show everything you need
    hie = ΔVbe/ΔIb at Vce constant.
    So from you measurement table we have

    hie = (0.3V - 0V)/(1mA - 0A) = 0.3V/1mA = 300Ω at Vce = 5V

    hfe = ΔIc/ΔIb at Vce constant = 9mA/0.3mA = 30 at Vce = 5V

    hoe = ΔIc/ΔVce at Ib = constant, hoe = (11mA - 7mA)/(17V - 0V) = 4mA/17V = 235μS at Ib = 0.3mA

    And I also think that your measurement are compliantly wrong or you use germanium transistor.
  3. LvW

    Well-Known Member

    Jun 13, 2013
    And I do not understand your question.
    What do you expect when you "use results of my table where results are 0" ?
    More than that, what is YOUR table? Only the last one?

    EDIT: What is the reason for selecting Vbe values between 0 and (only) 0.3 volts?
    Last edited: Nov 21, 2013