• Support PF! Buy your school textbooks, materials and every day products Here!

Thevenin equivalent with dependet sources

  • Thread starter elamre
  • Start date
  • #1
3
0

Homework Statement



Hello, i was studying diodes for my exam on monday, but i had some struggle finding the Thevenin equivalent. Here is the circuit:
http://img411.imageshack.us/img411/5336/schakeling.png [Broken]

Homework Equations



I have no clue what to put here?

The Attempt at a Solution



I have made 2 equations with which i should be able to solve it (i think?) But i have no clue if im doing it right! So can somebody check it?

ix = (5-Voc)/1000
and
ix - ix /2 = 5/1000

Homework Statement





Homework Equations





The Attempt at a Solution

 
Last edited by a moderator:

Answers and Replies

  • #2
gneill
Mentor
20,792
2,770
What is the motivation behind your second equation?
 
  • #3
3
0
Well i tried to follow an example out of my book (electrical engineering fifth edition by allan r hambley) And i need my second equiation to solve the first equation. Its just that i cant think of 2 =/.
 
  • #4
gneill
Mentor
20,792
2,770
Well i tried to follow an example out of my book (electrical engineering fifth edition by allan r hambley) And i need my second equiation to solve the first equation. Its just that i cant think of 2 =/.
I see. Well, it doesn't look like a valid equation to me.

Here's a trick that often helps with these types of circuits. If you consider a general Thevenin source it's a voltage supply Vth with a series resistance Rth. When it's connected to some load resistance R, the two resistances will form a voltage divider for the Thevenin voltage source and the voltage across the load will thus be
[tex] Vo = V_{th} \frac{R}{R + R_{th}}[/tex]

Now, if you stick a resistance R onto your circuit on the right as a load, you should be able to apply nodal analysis at the output node and solve for Vo. One equation! If you can then put the result in the form above you can read off both the Thevenin voltage and resistance directly.
 
  • #5
3
0
Well i know that, but what about the dependent source? :)
 
  • #6
gneill
Mentor
20,792
2,770
Well i know that, but what about the dependent source? :)
Solve for Vo with the dependent source in place, of course. You'll be finding the expression for the current Ix through the 1000Ω resistor as part of the node equation analysis, so you can substitute for Ix/2 easily.
 

Related Threads on Thevenin equivalent with dependet sources

Replies
2
Views
467
Replies
7
Views
5K
Replies
4
Views
4K
Replies
1
Views
3K
Replies
5
Views
4K
Replies
13
Views
1K
Replies
19
Views
2K
Replies
12
Views
2K
Top