Can somebody tell me the calaculations of this 2 transistor circuit?

[michael1978]

can somebody tell me this circuits calculations, how come 10mA
please

 

[berkeman]

can somebody tell me this circuits calculations, how come 10mA
pleaseView attachment 218125 View attachment 218125 View attachment 218125

Looks pretty straightorward, unless I'm missing something. Label the voltages of each node, and go from there...?

 

[donpacino]

can somebody tell me this circuits calculations, how come 10mA
pleaseView attachment 218125 View attachment 218125 View attachment 218125

To start do you know how to solve for BJT circuits?
If you do know the relationship between the different ports of a BJT, then you can do what berkeman said and dive into the math.

 

[LvW]

Just a short hint:
When you assume a "normal" (classical) value for the voltage across the B-E path of Q6 (linear operation of Q6), it is a very simple task to get a rough estimate for the current through a resistor which is in parallel to this B-E junctiun.

 

[michael1978]

why you make it so difficult?
it easy, i put the problem in other forum
this is the answer for there
The base-emitter voltage of the 2N5401 Q6 is about 0.62V when it begins to turn on. When Q6 turns on it begins to cutoff Q7 so the current in R9 and Q7 is constant at 0.62V/62 ohms= 10mA.

 

[donpacino]

why you make it so difficult?
it easy, i put the problem in other forum
this is the answer for there
The base-emitter voltage of the 2N5401 Q6 is about 0.62V when it begins to turn on. When Q6 turns on it begins to cutoff Q7 so the current in R9 and Q7 is constant at 0.62V/62 ohms= 10mA.

The goal of this forum is to share knowledge and grow the community and members, not to just blindly give you answers. In order to properly help you learn we need to know what level of experience you have, and why you are stuck on a problem. We won't spoon feed you answers if you don't respond to our questions.

 

[berkeman]

why you make it so difficult?

Why do you need to be given answers, when it is so easy to figure them out with our hints. You will not get very far in life with this approach, I'm afraid.

Thread is done.