0:00:00.000,0:00:05.525
Now that we know how to calculate the Thebonon equivalent circuit, it's very easy to get the Norton

0:00:05.525,0:00:08.936
from source transformation. The Norton equivalent current is going

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to be V Thevenin divided by R Thebonin, and the parallel resistor here will be

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equal to the series resistor in Febonin. Now let's talk about power transfer.

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When we have our active circuit, which we can model with a Febonin

0:00:24.264,0:00:27.900
equivalent circuit, and our passive circuit, which was modeled just as a load,

0:00:27.900,0:00:32.500
we might very often want to be able to maximize the power that gets to the load.

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Imagine what would happen if we increase this resistance.

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We can see that by increasing the resistance because we've got a voltage divider here,

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we get the larger possible voltage, but we get a much smaller current

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because from Ohm's law that says we have a higher resistance. What if I made the load very small?

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In that case I have a large current but a small voltage. So in fact,

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where's the maximum power transfer? If you calculate the current and you calculate the voltage,

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you'll come up with this equation right here. And if we plot that,

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we'll see that the maximum value happens when the load is equal to the source.

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So our maximum power transfer happens when Rs and RL are matched. You often say matched,

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and this is the maximum power that can be delivered to that load.

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Now here's our electrical engineering circuit analysis toolbox with the addition

0:01:20.920,0:01:25.082
of Thevenin and Norton included. Now, Febin and Norton are very important because

0:01:25.082,0:01:28.914
they allow us to simplify our circuit. They're somewhat like the resistors and

0:01:28.914,0:01:35.658
series and parallel law that allows us to simplify or the superposition. So let's say that this is

0:01:35.658,0:01:41.250
a simplification method, this is a simplification method, and this is a simplification method.

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The other methods can all be used in this Norton and Febin equivalent circuit.

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In fact, you saw us use the node voltage and this equation right here.

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Ohm's law can also be used voltage dividers and current dividers,

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all for doing the analysis that gives us the feminine and Norton equivalent circuits.

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So what did we do today? We talked about how to analyze systems of circuits that might be

0:02:05.345,0:02:08.640
more complicated by breaking them down into simple blocks using the

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concept of input and output resistance. We know that if the output resistance

0:02:12.572,0:02:16.765
is much smaller than the input resistance of the next block that we can

0:02:16.765,0:02:21.100
analyze these individually and if not, we can expect to see voltage loading.

0:02:21.100,0:02:24.152
We analyzed how to calculate feminine

0:02:24.152,0:02:29.780
equivalent circuits by open circuiting

0:02:29.780,0:02:34.660
the points A to B and measuring or simulating or calculating B feminine.

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And then we talked about three different methods of being able to measure our Thevenin.

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We know that we could convert this to a Norton equivalent circuit using source transformation.

0:02:44.700,0:02:49.580
And then we talked about maximum power transfer, which is where the block that has this

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input resistance rather the output resistance is connected to the load

0:02:53.491,0:02:57.948
and these two have to be matched or equal for maximum power transfer. Finally,

0:02:57.948,0:03:02.201
we talked about the updated EC analysis toolbox where we now know that we

0:03:02.201,0:03:05.780
can use Thevenin and Norton as one of our simplification tools and we

0:03:05.780,0:03:10.500
can apply any of the other circuit analysis tools to do our calculation.

0:03:10.500,0:03:17.068
So thanks very much for joining me for the discussion of Thevenin and Norton equivalent circuits.