# Transistor Circuit

1. May 14, 2014

### Tekneek

1. The problem statement, all variables and given/known data
So I am supposed to find Vo in this circuit. Given, Vb-Ve=0.7, ic=100ib, ie=ic+ib

3. The attempt at a solution
In order to solve for Vout i did KVL for the two loops:

Loop 1 (left side, clockwise):

Vb-Ve-ie(416)+2-ib(10*103)=0
0.7-ic(416)-ib(416)+2-ib(10*103)=0
0.7-ib(100)(416)-ib(416)+2-ib(10*103)=0
2.7-52016ib=0
ib=5.19*10-5A

ic=5.19mA
ie=ic+ib=5.2mA
Ve=ie(416)=2.18V (this one i am not sure)

Loop 2 (Right side, anti-clockwise)

10-ic(2*103)-Vo-Ve-ie(416)=0
Subbing in everything i get
Vo=4.7V

But the answer is supposed to be 5 Volts, i am not sure where i made a mistake.

2. May 14, 2014

### phyzguy

The 2V and the 0.7V in the left hand loop are in opposite directions, so they should subtract, not add, so you should get 1.3-52016*Ib=0.

Last edited: May 14, 2014
3. May 14, 2014

### Tekneek

I still don't get the right answer, this time around i get 7.87

4. May 15, 2014

### phyzguy

You've made another mistake in the right hand loop, but you don't really need that. With what I gave you, you should get Ib = 25μA. Ic = 100* Ib = 2.5 mA. Vout = 10.0 - 2.5mA * 2.0 kΩ = 5.0V