Hi,
We just finished covering transistors, i am unsure about how the equations that we use to work out IB, VE etc are derived. Mostly it's KVL but i can't get my head around how it has been done. I am putting up some typical circuits that we are meant to know at our level. It'll be helpful if someone can redraw the diagram with the V sources included. I get more confused when there is dual power supply.
Thanks
I have attached the images along with this post
Q1 (IMG 001)
for this one how would i find IB?
i don't understand how VCC and VEE are part of the KVL loop and what signs they would have? Also why don't we include RCIC and VC whilst doing KVL?
Q2 (IMG 007)
For this one why do we include REIE in the KVL, i thought the closed loop was just the IBRB. Also how would you find VE firstly? Now say there is RC as well then what? Would you go -VEE - VCC + ICRC + VC + IERE + VE = 0? Why do we treat that as a seperate loop?
Q3 (IMG 0022)
Again how would we do include VEE and VCC? Like i were to join this up with sources would the - end of source be connected to ground is that why the bottom point is -VEE? Does the left hand of the circuit join up to loop for IB is that why we include REIE?
Q4 (IMG 003)
For this one i know you do Thevenin, i want to know why is VTH the v drop across R2. NOTE VEE=-VCC. So again how would you do the KVL and this time i know when doing VTH it's VCC-VEE but the lecturer said you add VEE as well why?
Any help is appreciated
We just finished covering transistors, i am unsure about how the equations that we use to work out IB, VE etc are derived. Mostly it's KVL but i can't get my head around how it has been done. I am putting up some typical circuits that we are meant to know at our level. It'll be helpful if someone can redraw the diagram with the V sources included. I get more confused when there is dual power supply.
Thanks
I have attached the images along with this post
Q1 (IMG 001)
for this one how would i find IB?
i don't understand how VCC and VEE are part of the KVL loop and what signs they would have? Also why don't we include RCIC and VC whilst doing KVL?
Q2 (IMG 007)
For this one why do we include REIE in the KVL, i thought the closed loop was just the IBRB. Also how would you find VE firstly? Now say there is RC as well then what? Would you go -VEE - VCC + ICRC + VC + IERE + VE = 0? Why do we treat that as a seperate loop?
Q3 (IMG 0022)
Again how would we do include VEE and VCC? Like i were to join this up with sources would the - end of source be connected to ground is that why the bottom point is -VEE? Does the left hand of the circuit join up to loop for IB is that why we include REIE?
Q4 (IMG 003)
For this one i know you do Thevenin, i want to know why is VTH the v drop across R2. NOTE VEE=-VCC. So again how would you do the KVL and this time i know when doing VTH it's VCC-VEE but the lecturer said you add VEE as well why?
Any help is appreciated
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