Hello everybody and thanks always for your help.
This time I would like to ask a more general question related to transistors.
Say you have the following two schematics:
1) What is the difference in functionality between the two? Assuming I want to control the Lamp, which of the two circuits is most recommended?? What are the pros and cons of each one...
I am not good at doing calculations so please tell me if the following are correct.
If V= 10V , Ic is 100mA and the β of Q1 and Q2 is 100
circuit 1:
Ib= 100mA/100 =1mA
R1=(10V-0.7V) /1mA = 9.3kΩ
circuit 2:
Ib= 100mA/100=1mA
I3= 10*Ib = 10mA
I2=Ib+I3=11mA
therefore
R3= 0.7V/10mA= 0.07kΩ=70Ω
R2=(10V-0.7V)/11mA= 0.845kΩ= 845Ω
Is R3 necessary to maintain stability or something??
Thanks in advance for your advice
This time I would like to ask a more general question related to transistors.
Say you have the following two schematics:
1) What is the difference in functionality between the two? Assuming I want to control the Lamp, which of the two circuits is most recommended?? What are the pros and cons of each one...
I am not good at doing calculations so please tell me if the following are correct.
If V= 10V , Ic is 100mA and the β of Q1 and Q2 is 100
circuit 1:
Ib= 100mA/100 =1mA
R1=(10V-0.7V) /1mA = 9.3kΩ
circuit 2:
Ib= 100mA/100=1mA
I3= 10*Ib = 10mA
I2=Ib+I3=11mA
therefore
R3= 0.7V/10mA= 0.07kΩ=70Ω
R2=(10V-0.7V)/11mA= 0.845kΩ= 845Ω
Is R3 necessary to maintain stability or something??
Thanks in advance for your advice