h and y parameters for CB and CE transistors

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evol_w10lv

Joined Feb 19, 2013
4
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?
 

Jony130

Joined Feb 17, 2009
5,487
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.
 

LvW

Joined Jun 13, 2013
1,752
.......
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?
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?
 
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