#### khatus

##### Member level 2

Hello guys, I want to calculate the value of resistor R1 in the figure. But while doing the calculation I face the following problem

First, see the pictures below,

In my calculation, VBE =0.7 = I1* R1 to turn the transistor on. But here, but Here I1 = IREG was taken, so that

R1 * IREG = 0.7 volts.

I did not understand this part, In my calculation,

At the junction,

I1+IB = IREG

IREG - IB = I1

Now the Beta of the transistor is known and From the output current I can calculate IC and I can find IB from IC.

a) So I1 and IREG are not the same. So how did equal this two here?

b) Where can I find the maximum value of IREG?

c) To calculate the output current I need at least two quantities from ( I1, IB, IREG). How i can determine these two quantities

First, see the pictures below,

In my calculation, VBE =0.7 = I1* R1 to turn the transistor on. But here, but Here I1 = IREG was taken, so that

R1 * IREG = 0.7 volts.

I did not understand this part, In my calculation,

At the junction,

I1+IB = IREG

IREG - IB = I1

Now the Beta of the transistor is known and From the output current I can calculate IC and I can find IB from IC.

a) So I1 and IREG are not the same. So how did equal this two here?

b) Where can I find the maximum value of IREG?

c) To calculate the output current I need at least two quantities from ( I1, IB, IREG). How i can determine these two quantities

Last edited: