# mesh current analysis in bjt circuits

#### Doubtician

Joined Mar 19, 2022
18
How to use mesh current analysis instead of thevenin's theorem here to solve for all currents and voltages in the following bjt circuit?

How should i make the closed loops in order to analyse?

#### ericgibbs

Joined Jan 29, 2010
18,032
Hi D,
E

#### RBR1317

Joined Nov 13, 2010
709
...solve for all currents and voltages in the following bjt circuit?
A good place to start is to replace the BJT with the circuit model of a BJT.

#### Doubtician

Joined Mar 19, 2022
18
Hi D,
E

I tried to find base current by applying kvl in the marked part of the circuit.

Can i use I2 as the base current?

#### ericgibbs

Joined Jan 29, 2010
18,032
hi D,
This simulation should give you a clue that a parameter is missing from the posted question.
E

#### Attachments

• 51.6 KB Views: 11

#### Doubtician

Joined Mar 19, 2022
18
hi D,
This simulation should give you a clue that a parameter is missing from the posted question.
E

Which parameter? beta?

#### ericgibbs

Joined Jan 29, 2010
18,032

#### Attachments

• 1.6 MB Views: 2
Last edited:

#### Doubtician

Joined Mar 19, 2022
18
Hi D,
The current in R3 [Emitter] will be higher than you calculated, due to the gain factor of the transistor.
Do you have a copy of the complete question you could post?
E
example 4 in this link here.
They used thevenin's theorem, i was just trying to find it through mesh analysis.The answer they get for emitter current is 1.29 mA while what i get through mesh analysis is 1.4 mA .