Different voltages on the same node?

  • Thread starter yosimba2000
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In summary, the picture shows a circuit with an independent voltage source and a dependent voltage source connected at node A. The voltage at node A is 10V and the dependent source is at 2V. KVL on the left loop shows that the current is 0.2A, which is used to determine the voltage across the dependent source. KVL on the right hand loop can be used to show that the voltages at node A and the dependent source are not inconsistent.
  • #1
yosimba2000
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In this picture: http://imgur.com/lfNiDjL

I see that at node A, the voltage is 10V since it is connected to the independent voltage source. But node A is also connected to the dependent voltage source 10Io.

If I do KVL on the left loop, Io comes out to be 0.2A. Plugging this into the dependent source, the dependent source is at 2V. How is this possible?

The dependent source says Node A is at 10V. But the dependent source says Node A is at 2V. Since both sourcers are connected at the same point, they should be at the same voltages, right?

Which voltage is correct? How am I analyzing this incorrectly?
 
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  • #2
10V at node A, period. That fixes the current through R1, which determines the voltage across the dependent source, which is referenced to node A. The dependent source is 10V on the left side and 12V on the right since there is 2V across it.
 
  • #3
yosimba2000 said:
In this picture: http://imgur.com/lfNiDjL

I see that at node A, the voltage is 10V

A single node cannot have a "voltage".
A voltage always is the potential DIFFERENCE between two nodes.
Only in case one node is grounded we speak about a "node voltage" - without mentioning that this automatically means: Referenced to the grounded node.
 
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  • #4
yosimba2000 said:
I see that at node A, the voltage is 10V...

That is 10V wrt the bottom end of R1.

If I do KVL on the left loop, Io comes out to be 0.2A. Plugging this into the dependent source, the dependent source is at 2V.

That is 2V wrt the node between the dependent source and R2.

So they need not be inconsistent.

Mark these voltages on the drawing and apply KVL to the right hand loop.
 

FAQ: Different voltages on the same node?

1. What is meant by "different voltages on the same node"?

When multiple voltage sources are connected to the same circuit node, the voltage at that node will be determined by the sum of all the voltages acting on it. This can result in a voltage that is different from any of the individual sources.

2. Can different voltages on the same node cause damage to a circuit?

Yes, if the voltages are not compatible or if there is a large difference between them, it can lead to damage or malfunction of the circuit components. This is why it is important to carefully design and regulate the voltages in a circuit.

3. How can different voltages on the same node affect the performance of a circuit?

Different voltages on the same node can affect the performance of a circuit in several ways. It can cause unexpected currents to flow, alter the behavior of components, and change the overall output voltage or current of the circuit.

4. What can be done to mitigate the effects of different voltages on the same node?

There are a few ways to mitigate the effects of different voltages on the same node. One option is to use a voltage regulator to ensure a consistent voltage at the node. Another option is to use voltage dividers to reduce the effects of the different voltages. Additionally, proper circuit design and careful selection of components can also help mitigate the effects of different voltages.

5. Is it possible for different voltages on the same node to cancel each other out?

Yes, it is possible for different voltages on the same node to cancel each other out if they are equal in magnitude and opposite in direction. This is known as a voltage balance or voltage cancellation and can be used in certain circuit designs to achieve specific results.

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