beenuseren
New Member
Could anyone tell me about the re model of a transistor? How is the transistor represented with the re parameters? How to arrive to that model?
Help me please.
Help me please.
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beenuseren said:Before I understand the re model I have another doubt.
Let us consider ,man NPN transistor with CE configuration.
If we connect a load across the collector and the ground, does it change the collector to ground voltage?
I mean does the load current effect the collector current, Vce, and base current?
hjames said:It depends on the load - is it resistive, inductive, capacitive, or some combination of the three? If you just change the output impedance attached to the collector, and keep the collector current the same, what do you think will happen to the voltage at the collector?
The other question you need to be asking is : "If I change the load impedance, do I need to re-bias the transistor?"
beenuseren said:hjams, I am quite confused. Here is my doubt:
For a voltage divider biased circuit( CE config), the operating point doesnot change with the addition of load to the collector and ground. How is it possible? Addition of load should alter the collector current, Vce
and voltage drops across Rc, Re, theoretically.
What I think is , if we donot want to change the operating point, then the load impedence should be very high when compared with the source impedence.(Here the source impedence is the output impedence of the BJT).
Am I right?
If so, how will we know, what load value we can use, for a any biased BJT ?
Is there any calculation?