EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: stafil on May 31, 2020, 06:49:32 pm
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I learned how to analyze circuits using KVL, KCL. but I am still having trouble with intuition when connecting more that one power sources that may have different potential.
For example consider 2 scenarios for the simple circuit below.
Let's assume in the first scenario the negative of V1 has 0 potential in regards to earth, while the negative of V2 has -5V potential in regards to earth. While in the second scenario they are both 0.
How does it happen that they both solve the same?
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The negative terminals of V1 and V2 are directly connected so they'll always be at the same potential.
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The scenario shown does not have any references to ground indicated which makes the question incomplete and/or ambiguous.
If I were to guess at the question, the solution for an isolated circuit will be the same no matter what the voltage is with respect to earth, so long as there is only one connection to earth (ie - there is no circuit path you can trace back to a different point within the original circuit.)
Except for electrostatic levels, voltages only count when they are part of a circuit (ie - circular topology)