Non-ideal voltage source V-I characteristic

Thread Starter

Xefro1337

Joined Aug 18, 2019
2
Hey all,

I have been going around in circles trying to figure this one out for a couple days now but just cannot seem to wrap my head around it.

From what I can gather the slope is -Rs but I cannot seem to get the correct answers for A and D.

This concept is doing my head in and I feel like it is easier than what I expect.

Any help is greatly appreciated.

Capture.PNG
 

MrChips

Joined Oct 2, 2009
21,041
Welcome to AAC!

R is a linear component that obeys Ohm's Law:

I = V / R

What does this relationship look like when drawn on the V - I graph?
 

Thread Starter

Xefro1337

Joined Aug 18, 2019
2
Welcome to AAC!

R is a linear component that obeys Ohm's Law:

I = V / R

What does this relationship look like when drawn on the V - I graph?
Thanks for the quick reply
I just cannot seem to grasp the relationship of the resistor in respect to the V-I graph and finding the current with the resistor value.
 

Jony130

Joined Feb 17, 2009
5,162
Here you have an example of how to plot a 1Ω resistance into your V-I graph.


untitled.PNG


All you need is a Ohm's law.

1A*1Ω = 1V
2A*1Ω = 2V
3A*1Ω = 3V

And plot in on the graph.


But we can find is analytics.

Simply notice tha that until load current is smaller than 2.5A. Your Non-ideal voltage source act just like an ideal voltage source.

But for a large currents (I > 2.5A) your Non-ideal voltage source act lika a non-ideal current source with internal resistance.

As I show here:

ccc.PNG


Now you can use your V-I graph and solve for Ri resistance and read from the graph the Is value.
 
Last edited:

WBahn

Joined Mar 31, 2012
25,731
Thanks for the quick reply
I just cannot seem to grasp the relationship of the resistor in respect to the V-I graph and finding the current with the resistor value.
I'm guessing that you haven't looked at Hayt Fig 2.23 as was suggested. I haven't seen the figure, but I'm guessing that it is showing how to plot the I-V characteristic of a linear resistor.

What you are being asked to do is to perform a "load line" analysis of the system. You have two parts of a system that are connected together. At the point of the connection they share a common voltage and current. So if you plot the voltage and current of both sides on the same graph, what do you know about the point at which the system is actually operating?
 
Top