need to explain my teacher solved example

Thread Starter

SUN SHINE

Joined Jan 6, 2017
13
Hi

i studied and i do many exersices but i could not be able to undestant my teacher exAMPLE
how did he move from (a) to (b) to the rest

thanks in advance
 

WBahn

Joined Mar 31, 2012
25,071
Hi

i studied and i do many exersices but i could not be able to undestant my teacher exAMPLE
how did he move from (a) to (b) to the rest

thanks in advance
Did you intend to attach a file? If so, it didn't work. Please upload whatever it is that you meant to.
 

DGElder

Joined Apr 3, 2016
351
"...i could not be able to undestant my teacher exAMPLE
how did he move from (a) to (b) to the rest"


We need pertinent data.
Is Mr. exAMPLE a chicken?
And is b) on the opposite side of the road from a) ?
 

Thread Starter

SUN SHINE

Joined Jan 6, 2017
13
ı am sorry ı wrote the question quickly so i missed important parts...

i was trying to say that i'v studied Thevenin's theorem and i did many example from Parta book
but when i tried to solve my teacher example it seem so different
i will re-upload the examples again
 

Attachments

WBahn

Joined Mar 31, 2012
25,071
Thanks for posting some images. It's still a bit hard to follow what you are asking, but we'll work though things as we go. We understand that English is not your native language, as so we will work on any miscommunication as they come up.

The diagram in (a) is missing a pretty important piece of information and it requires you to make an assumption. It is actually pretty meaningless to ask what the Thevenin equivalent of a circuit is because the Thevenin equivalent is a view of the circuit as seen between a particular pair of nodes. Second, the goal is often, but not always, to find the Thevenin equivalent as seen between a particular pair of nodes while treating one or more components connected between those nodes as a load, which requires that those components be removed from the circuit, then the Thevenin equivalent of the rest of the circuit be found when viewing it between those pair of nodes, then the load components be inserted into the Thevenin equivalent. The whole point is to make finding the voltage across and current through the load components much easier than analyzing the entire circuit.

So in this case they are assuming that you will assume that the 1 kΩ resistor is the load component and that you are trying to find the Thevenin equivalent circuit as seen between the two nodes that the 1 kΩ resistor is connected to.

So first remove the 1 kΩ resistor from the circuit. Then turn off all of the independent sources in the circuit. You do this by setting the voltage of any independent voltage sources to 0 V. This allows any current to flow through the source while maintaining 0 V across it, which is exactly the behavior of a short circuit. So you can just replace each independent voltage source with a short circuit. Then you set the current in any independent current source to 0 A. The allows any voltage to appear across it while maintaining 0 V through it, which is exactly the behavior of an open circuit. So you can just replace each independent current source with an open circuit.

Do those things and see if you can understand how they got to (b).
 
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