# thevenin equivalent

Discussion in 'Homework Help' started by illidari, Sep 6, 2011.

1. ### illidari Thread Starter New Member

Aug 26, 2011
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I am really lost on how to solve this problem with the current sources in the picture.

I have found the thevenin resistance equivalent to be 571.43 ohms

I am stuck on finding the thevenin voltage.

Could someone explain this to me ? Possibly show me the first few steps?
I was told to turn the voltage into a current by dividing 5V/1kohms = .005A

I'm not sure what to do next.

2. ### cloud18 New Member

Sep 6, 2011
9
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You can try these techniques (Mesh, Nodal or Source Transformation)

3. ### illidari Thread Starter New Member

Aug 26, 2011
3
0
Not exactly familiar with those

Apr 26, 2005
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5. ### illidari Thread Starter New Member

Aug 26, 2011
3
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I tried the node voltage method. I'm stuck on solving it. I attached the work I got done with it.

I'm still lost on how to move forward.

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6. ### Jony130 AAC Fanatic!

Feb 17, 2009
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Now you can turn the 5mA current source into the voltage source

7. ### wo0t New Member

Jan 21, 2011
4
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is the thevenin voltage 2001.67V ?

8. ### Jony130 AAC Fanatic!

Feb 17, 2009
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No
Vth = 8005/7 = 1.143KV

9. ### wo0t New Member

Jan 21, 2011
4
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if you don't mind, can you share with me what is the step to get 1.143kV ? Thanks !

10. ### Jony130 AAC Fanatic!

Feb 17, 2009
3,957
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We can write down the nodal equation directly form the diagram

I1 = Va/R4 + (Va - Vc)/R2

(Va - Vc)/R2 = Vc/R3 + (Vc - V1)/R1

Or we can use source transformation technique

And now we can find Vab voltage

Vab = V2 - I1*R4 = V2 - (( V2 - V1) / ( R4 + R2 + R1||R3 )*R4 ) =

= 2KV - (( 2KV - 5/3) / (1KΩ + 1KΩ + 1KΩ/3 ) *1KΩ ) =

= 2000V - 856.428571V = 1143.57143V

wo0t likes this.
11. ### wo0t New Member

Jan 21, 2011
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Thank you very much !